Stephanie Norris Architects

Stephanie Norris Architects

BROWNE’S HOSPITAL: STAINED GLASS CONSERVATION

For the Trustees of Browne’s Hospital

SPECIFICATION & SCHEDULE OF WORKS July 2020

Browne’s Hospital: Stained Glass Conservation: Specification & Schedule of Works

1924-SPEC-020720 Page 2 of 49

STEPHANIE NORRIS

BA(Hons) BArch DipAM RIBA AABC

Stephanie Norris Architects Ltd

8 The Coppice

Impington

Cambridge CB24 9PP

Tel: 07786 360552

[email protected]

All rights in this work are reserved. No part of this work may be reproduced, stored or

transmitted in any form or by any means (including without limitation by photocopying or

placing on a website) without the prior permission in writing of Stephanie Norris Architects Ltd

except in accordance with the provisions of the Copyright, Designs and Patents Act 1988.

mailto:[email protected]


1924-SPEC-020720 Page 3 of 49

CONTENTS

1.0 Preliminaries 4

2.0 General Obligations 8

3.0 Specification: Trade Clauses 16

4.0 Schedule of Works 28

5.0 Collection Page 36

Appendix 1: Photographs 37

Appendix 2: The CVMA Numbering System 46

Appendix 3: List of abbreviations to be used on stained glass diagrams 47

Appendix 4: Form of Tender 48

Appendix 5: The York Glaziers Trust Report and Condition Advice 2017 (separate doc)


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PRELIMINARIES

A1 NAMES AND ADDRESSES

Employer:

The Trustees of Browne’s Hospital, Stamford

c/o Mr David Wallington (Trustee) 67a Casterton Road

Stamford

PE9 2UB

07721 343618

[email protected]

Architect:

Stephanie Norris

Stephanie Norris Architects Ltd

8 The Coppice

Impington

Cambridge CB24 9PP

07786 360552

[email protected]

Principal Designer:

Philip Waller

Philip Waller Consulting

Meadow House

Longmeadow

Brundall

Norwich NR13 5LY

01603 959788 | 07471 655642

[email protected]

A2 DESCRIPTION OF SITE

Location of site: Browne’s Hospital, Broad Street, Stamford PE9 1PF

Access and confines of working area for Contractor, to be agreed at Pre-contract site

meeting.

The Contractor is deemed to have visited the site, to have taken into consideration all

local and existing conditions and to have made himself thoroughly acquainted with the

position and accessibility of the proposed works and the conditions under which they will

have to be carried out. Arrangements for visiting the site shall be by appointment only.


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A3 DESCRIPTION OF THE WORKS

The work is to include the necessary conservation glazing repairs and fabrication and

installation of an environmental protective glazing (EPG) system to Chapel windows sII

and sIII, Audit Room windows sII, sIII and sIV and nII, and the small Entrance passage

window (un-numbered – ‘EPW’). See locations on dwgs 1924/101 and 102.

The work to also include a few, relatively minor, stonework repairs needed to some

mullions, tracery and stone surrounds.

A4 CONTRACT DOCUMENTS

The Contract Documents will be the same as the tender documents, incorporating the

main contractors priced schedule of work, and will be as follows:

1. The Specification & Schedule of Work (hereafter called the Specification).

2. The JCT Minor Works Contract 2016 Edition, as described in specification item A5.

3. The following drawings: 1924/101, 102, 103, 104

A5 CONTRACT PARTICULARS

The form of contract will be the JCT Minor Works Building Contract, 2016 Edition. The

following is operative:

Attestation The agreement will be executed under hand.

4th Recital &

Schedule 2

Base date 3 working days prior to the

date for tender return

4th Recital &

Clause 4.2

Construction Industry Scheme (CIS) Employer at Base Date is

not a contractor for the

purposes of the CIS

5th Recital CDM Regulations The project is not

notifiable

6th Recital Framework Agreement N/A

7th Recital &

Schedule 3

Supplemental Provisions

Collaborative working Supplemental Provision 1

applies

Health and safety Supplemental Provision 2

applies

Cost savings and value improvements Supplemental Provision 3

does not apply

Sustainable development and environmental

considerations

Supplemental Provision 4

does not apply


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Performance indicators and monitoring Supplemental Provision 5

does not apply

Notification and negotiation of disputes

Supplemental Provision 6

does not apply

Article 7 Arbitration Article 7 and Schedule 1

(Arbitration) apply

2.2 Works commencement date To be agreed

2.2 Date for Completion To be agreed

2.8 Liquidated damages At £100 per week

2.10 Rectification Period 12 months from the date

of Practical Completion

4.3 Interim payments: Interim Valuation Dates The first Interim Valuation

Date is TBC and

thereafter at intervals of

1 month

Payments due prior to practical completion –

percentage of the total value of work etc.

95%

Payments becoming due on or after practical

completion – percentage of the total amount

to be paid to the Contractor

97.5%

4.3 & 4.8 Fluctuations provision no fluctuations provision

applies

Percentage addition for Schedule 2 N/A

4.8.1 Supply of documentation for computation of

amount to be finally certified

3 months from the date

of Practical Completion

5.3 Contractor’s Public Liability Insurance: injury

to persons or property (for any one

occurrence or series of occurrences arising

out of one event)

£5M for each and every

claim

5.4A, 5.4B & 5.4C Insurance of the Works etc. – alternative

provisions

Clause 5.4B applies

(Works & existing

structure insurance by

Employer in Joint Names)

5.4A.1, 5.4B.1 &

5.4C.1

Percentage to cover professional fees 15%

9.4.1 Adjudication The Arbitrator is the

President or Vice-

President of the Royal

Institute of British

Architects

The Conditions Contract Guarantee Bond Not required


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A6 TENDERING

Tendering procedure

In accordance with the principles of: JCT Practice Note 6 (Series 2) 'Main Contract

Tendering'.

Arithmetical errors: Alternative 1 is to apply.

General: Tenders must include for all work shown or described in the tender documents

as a whole or clearly apparent as being necessary for the complete and proper

execution of the Works.

Exclusions

Inability to tender: Immediately inform if any parts of the work as defined in the tender

documents cannot be tendered.

Relevant parts of the work: Define those parts, stating reasons for the inability to tender.

Acceptance of tender

No guarantee is offered that any tender will be recommended for acceptance or be

accepted, or that reasons for non-acceptance will be given.

Costs: No liability is accepted for any cost incurred in the preparation of any tender.

Period of validity

After submission, keep tender open for consideration for not less than 12 weeks.

Priced documents

Alterations: Do not alter or qualify the priced documents without written consent. Tenders

containing unauthorised alterations or qualifications may be rejected.

Measurements: Where not stated, ascertain from the drawings.

Deemed included: Costs relating to items which are not priced, will be deemed to have

been included elsewhere in the tender.


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GENERAL OBLIGATIONS

Statutory

Obligations

Comply with statutory obligations and regulations, give all notices, pay all

fees and charges required by any Local Authority, Public Service or Statutory

Undertaker, Police, Safety, Health and Welfare.

Give notice to the Local Authority for inspections at all necessary stages

required under the Building Regulations. Ensure a Notice of Completion is

issued by the Local Authority to the Employer as soon after Practical

Completion as possible.

Prevention of

Accident/

Nuisance

Take all reasonable precautions necessary to prevent accidents or nuisance

due to fire, noise, dust, smoke, water, rubbish etc.

No radios to be used on site.

Prevention of

Damage/Loss

a) Public and Private Services

Notify all service authorities of proposed works before commencing site

operations. So far as reasonable ascertain location of services or confirm that

none exist in the vicinity of the works.

b) Maintenance of Roads etc.

Make good any damage beyond fair wear and tear caused by site traffic or

site operations to Employer’s private roads and footpaths.

Keep approaches to the site clear of mud and debris.

c) Trees and Shrubs

Protect and preserve all trees and shrubs except those to be removed, in

accordance with BS 5837 Trees in relation to design, demolition &

construction. Large shrubs growing on the walls are to be pulled back

carefully and given temporary support wherever possible.

d) Existing Features

Protect existing buildings, fences, gates, walls, paved areas and other site

features that are to remain in position during execution of the works.

Asbestos

Containing

Materials

Report immediately any suspected materials discovered during execution of

the Works.

Do not disturb.

Agree methods for safe removal or encapsulation.

Progress a) Programme

Prepare in an approved form a programme chart for the works, including

work of all domestic and nominated subcontractors and other work

concurrent with the Contract.

Submit three copies of programme to the Architect at least one week prior

to contract commencement and keep one copy in the site office.

Record progress on the site office copy and update/redraft as circumstances

arise and submit all revisions to the Architect.


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b) Site Meetings

Hold monthly progress site meetings and attend weekly site visits.

Resources,

Temporary

Works & Services

a) General

Maintain, alter, adapt and move temporary works and services as necessary.

Clear away when no longer required and make good.

b) Buildings

Provide as necessary temporary facilities for offices, mess rooms, sanitary

accommodation, secure stores for materials etc as required for your own use.

c) General Scaffolding

Provide as necessary general scaffolding for the execution of the works.

d) Name Board

Obtain approval for and provide a suitable temporary name board

displaying consultants and contractors name plates.

e) Telephone

Provide temporary telephone facilities for your own use.

f) Water, Lighting & Power

Provide clean, fresh water, electricity and all equipment for lighting and

power for the works, make temporary arrangements for storage (water) and

distribution about the site. Provide lighting for any temporary hoardings and

the like.

g) Plant Costs

Provide all plant, tools and vehicles for the execution of the works.

h) Labour Costs

Allow for all labour on costs.

Commodities & Workmanship

Quality, Testing

& Approvals

a) Commodities

To be new unless otherwise specified. Handle, store and fix commodities with

care to ensure that they are in perfect condition when incorporated into the

work.

b) Manufacturers’ Recommendations

Handle, store and fix each commodity in accordance with manufacturers’

recommendations. Inform Architect if this conflicts with any other specified

requirement. Submit copies of manufacturers’ recommendations to

Architect when requested.

c) British Standards

For commodities specified to a British Standard obtain certificates of

compliance from manufacturers when requested by Architect.


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d) Samples: Commodities

Where approval of commodities is specified submit samples. Do not confirm

orders for commodities until approval has been obtained. Retain approved

samples on site for comparison with commodities used in the Works. Remove

when no longer required.

e) Samples: Finished Work

Where samples of finished work are specified obtain approval before

proceeding with the works. Retain approved samples on site for comparison

with the works. Remove when no longer required.

f) Building Regulations

Main Contractor to ensure regular site visits by Building Inspector as required

under Building Regulations and obtain the Completion Certificate at the end

of works.

Accuracy a) Setting Out

Set out the works accurately from information provided by the Architect.

Inform the Architect when overall setting out is complete and before

commencing construction.

b) Dimensions

Check all dimensions both on drawings and site, particularly the correlation

between components and the work in place. Drawings must not be scaled,

work only to figured dimensions.

c) Discrepancies

The Architect must be notified of any discrepancies in the drawings or

specification immediately.

Protection a) The Site

Safeguard the site, works, materials and plant from damage and theft. Take

all reasonable precautions to prevent unauthorised access to the site, works

and adjoining property.

b) Cleanliness

Keep the site and works clean and tidy. Clear away debris and surplus

material as it accumulates.

Drying Allow for drying the works.

Completion Leave the works clean and tidy at completion.

Nominated Firms/Public Bodies

Prime Cost or

Provisional Sums

For all work to be executed or commodities to be supplied by nominated

subcontractors, nominated suppliers or public bodies have been included

elsewhere in the contract documents.

Warranties Forms of Warranty will be sought by the Employer from all nominated firms.

You should not enter into subcontracts until you are satisfied that Forms of

Warranty exist.


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General

Attendance

Provide general attendance on nominated firms and public bodies

including:

a) Use of standing scaffolding.

b) Use of general facilities.

c) Space for office accommodation, storage of plant and of materials.

d) Light, power and water.

e) Clearing away rubbish.

Supervision &

Administration

Accept responsibility for the supervision, administration, co-ordination and

integration of work of all subcontractors, suppliers and public bodies.

A complete set of legible contract drawings must be kept on site at all times.

Update as necessary and make available for Architect’s use as required.

Daywork No additional work is to be carried out the value of which cannot be

ascertained from the priced specification without the prior agreement of the

Architect except where this would prevent the Contractor fulfilling his

obligation under the Contract.

Maintenance

Instructions

Copies of maintenance instructions and guarantees shall be obtained from

subcontractors and manufacturers as required and given to the Architect

within 14 days of Practical Completion.

Fire Precautions Take all necessary precautions to prevent personal injury, death and

damage to property and the fabric from fire. This care is to include:

a) No smoking on site.

b) No burning of rubbish on site. All rubbish must be removed from site.

c) Inflammable materials must not be stored on site.

d) Hot Work

The general rule is that hot work is prohibited on site. In certain circumstances

permission may be given where there is no practical alternative. If the

Contractor wishes to carry out hot work he should make a prior application

to the Architect for written consent.

Hot work is defined as operations involving:

Flame, hot air or arc welding and cutting equipment brazing and soldering,

blowlamps, bitumen boilers, electrical element burners and other equipment

producing naked flame and heat (e.g. high-speed drilling of any hard

material which may be combustible or near combustible material).

Where the Architect’s written permission has been received the contractor is

to take all precautions to minimise fire risks.

Where prefabrication and Hot Work e.g. lead burning can be carried out at

a minimum distance of 6 metres outside the building, on the ground and with

no combustible materials within 6 metres of the Hot Work operation, it should

be. Only as a last resort should hot work be carried out from the scaffolding

or in the building.

Precautions to minimise fire risks should include:

i) Removal of combustible materials as agreed with Architect. Cleaning the

area to remove dust and rubbish.

ii) Ventilation of enclosed spaces.


1924-SPEC-020720 Page 12 of 49

iii) Prior saturation with water of combustible materials that cannot be

removed as agreed with Architect.

iv) Temporary covering of immovable combustible surfaces with a 50-75mm

thickness of damp sand as agreed with Architect.

v) Removal of containers of inflammable gases or compressed gases.

vi) Protection of surrounding areas with flame retardant boards or other

suitable fire-resistant material.

vii) The use of butane and not paraffin lamps where appropriate.

viii) Confining the Hot Work to mornings only.

The Contractor is to provide firefighting equipment including:

i) Two portable extinguishers, buckets of water or sand to be immediately to

hand.

ii) Fire hoses to hand (where appropriate and practical).

iii) Adequacy of water supply, and water pressure.

iv) Knowing the location of the nearest telephone. Builder’s tools for opening

up roofs, walls, telephone floors, etc.

v) Alerting the fire brigade of the time and location of the Hot Work.

Where the building has automatic fire detection systems the Contractor

should make themselves aware of the Fire Instructions and procedures to be

followed in the event of a fire.

The operatives to carry out the Hot Work are to be suitably qualified and

experienced.

Numbers to be involved never to be less than 3 (i.e. 2 in addition to the

experienced operative for standby surveillance).

Following Hot Work the contractor shall remain at the location for at least 1

hour after completion of the task (except for any essential minimum break, in

which event alternative cover must be provided), during which time

continuous inspections of the work shall be made with particular reference to

the surrounding area to ascertain that there is no ignition.

A further inspection shall be made approximately 2 hours after the cessation

of the Hot Work by the Contractor in conjunction with one of the standby

operatives.

A record shall be made of the Hot Work by the Contractor and shall be sent

to the Architect for filing with original written consent. This record is to include

times, locations and subsequent checking information.

Fire extinguishers and appropriate fire-fighting equipment must be to hand

during the whole of the attendance time.

NOTE: It may be prudent to advise Insurers in advance of the Hot Work

operation so that they can inspect and, if necessary, approve procedures to

be adopted.


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Policy Note

(Fire) 4/92

Use of Portable Halogen Lamps

The use of portable halogen lamps for building and conservation works is

barred. This does not affect the use of halogen lamps that are permanently

secured, for such uses as floodlighting security lighting or emergency lighting.

In these instances:

i) The angle of the lamp must be secured.

ii) The lamp must be fitted with a metal guard to avoid contact with any form

of material.

iii) No combustible material or fitting which may be used for attaching

combustible material shall be within two metres.

Hand held battery operated halogen lamps for conservation inspection work

are not affected by this instruction.

Fluorescent, single or multi tube fittings are a low heat producing source and

is one acceptable alternative.

Bats The Wildlife and Country Act 1981 gives full protection to bats. It is illegal to kill,

injure or handle bats and to intentionally damage or destroy a place used by

bats for shelter or protection, or to obstruct access to such a place.

Information on looking for bats etc in buildings is available from Natural

England. Ensure employees and visitors to the site receive suitable instruction

and awareness training.

During the works, if the Contractor finds evidence of bats in the building he is

to immediately:

i) Stop work.

ii) Contact Natural England.

iii) Inform the Architect.

The Contractor is not to proceed with work until instructed by the Architect in

writing.

Timber Treatment

Under no circumstances shall organochlorine woodwork killers (eg lindane)

and fungicides be used. Synthetic pyrethroid insecticide, such as permethrin

and cypermethrin can be used by an approved timber specialist.

Antiquities and

Excavations

Any fossils and other objects of interest or value which may be found on site

or within the fabric of the building or during excavations are the property of

the Employer. On discovery of such objects the Contractor must immediately:

a) Cease work. Keep objects in the exact position and condition in which

they were found.

b) Advise the Architect immediately. It may be necessary to call in an

Archaeological Advisor to inspect.

The Contractor is not to proceed with work in the area until instructed by the

Architect in writing.

Health & Safety CDM Regulations 2015

The Contractor must take all reasonable steps to ensure the Health & Safety

of those working on and visiting the construction site in accordance with all

relevant Codes of Practice.


1924-SPEC-020720 Page 14 of 49

The Contractor must allow for full compliance with the current CDM

Regulations and, where required, give notice of the project to the Health &

Safety Executive prior to construction work commencing (normally for work

lasting more than 30 days and involving 20 or more workers at any one time).

Where projects are notifiable or where more than one contractor is involved

in the works or the Contractor is to employ one or more subcontractors, then

the Contractor, unless otherwise stated, must allow for providing the role of

Principal Contractor (PC) within the meaning of the CDM Regulations. This will

involve liaising with the separate contractors on all matters concerning health

and safety on the site and ensuring proper coordination of all the work on

site.

Where more than one contractor is involved in the works or the Contractor is

to employ one or more subcontractors, the Employer will ensure that a

Principal Designer (PD) is appointed for the project and they will be

responsible for issuing Pre-Construction Information and ensure that a Health

and Safety File for the project is prepared on completion.

At the time of tender, Contractors must allow for full compliance and Health

and Safety obligations.

The PC when appointed must:

a) Prepare a Construction Phase Plan (CPP) prior to starting work. The CPP

must be acceptable to the PD and submitted in good time.

b) Discuss and advise all subcontractors with regard to the requirements of

the CPP.

c) Demand the full co-operation of all subcontractors.

d) Ensure that all subcontractors employees are informed of on-site risk and

know enough about the CPP to comply with it.

e) Perform the same function with all of his own direct employees.

f) Take reasonable steps to keep unauthorised persons off site.

g) Update the CPP throughout the duration of the job.

h) Provide the necessary information to the PD to enable him to include that

information in the Health and Safety File.

i) Provide adequate training to all site operatives.

j) Consider all site generated risks and hazards including those arising from the

design. These should be notified to the PD.

k) The Health & Safety Executive no longer deems the use of ladders and

working on flat roofs to be safe. They recommend that no work is carried out

from a ladder over five metres high. If the ladder is over five metres it must be

secured to approved and tested fixings, it is not acceptable to have an

operative footing a ladder. Flat roofs must have parapets a minimum of 1100

mm high. If this is not the case a handrail must be erected, whatever the size

of the project. It is no longer acceptable to work overhand, for example

bedding coping stones unless a safety line exists.


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SPECIFICATION: TRADE CLAUSES

LEADED LIGHT GLAZING

To be read in conjunction with Preliminaries and Schedule of Work

Outline Scope of Work for existing stained glass leaded lights

Stained glass and leaded light glazing to only be carried out by an approved specialist glazier

with ICON accreditation to appropriate level.

Removal of stained glass and installation of protective glazing

In situ

photographic

recording

Photograph digitally all panels internally from the scaffold access in

transmitted and reflected light and externally in reflected light. These

general overall photographs must be supplemented with detail

photographs of any damage, defects or discoveries made before

removal.

a) Each photograph is to be named giving its window and panel number

and filed within folders for each window.

b) Three copies of these photographic records are to be prepared on CD

or DVD, one set for the Client, one for the Architect and one for the

contracted conservation studio.

Numbering of

glazing panels

Each glazing panel is to be numbered following the CVMA numbering

system. (See Appendix 2.) Acid free labels with each window and panel

number clearly printed on them are to be attached to the external face

of the panels. Ensure that the selected position to apply the label is free

from surface dust and has no back painting.

Inspection and

recording insitu

Inspect glazing and record existing damage, defects and support systems.

Inspect each panel and related fabric. Make written record of site specific

conditions such as saddle bar installations, noting material, profile, sizes

and location; cill, head and jamb details; damage and discoveries.

Provide 2no. hard copies of the inspection report to the Architect.

Protection of the

works area

Prior to commencing of removal works, protect the work area by dust sheet

covering the scaffold boards and the stained glass where necessary with

Correx box sheeting to prevent damage from mortar debris. Provide safe

panel racking system to store removed stained glass on the scaffolding on

removal, prior to lowering to the ground.

Removal of

mortar and putty

Remove mortar from the glazing grooves using conventional hammer and

chisel techniques aided where found helpful with a Fein oscillating tool or

equivalent. Keep work areas regularly clean by sweeping up debris and

bagging for disposal. Note: the mortar may be cement rich and hard.

Proceed carefully to avoid undue damage to the stonework.

Remove putty from saddle bars as found necessary to enable safe removal

with hand tools or Fein oscillating tool or equivalent. Keep work area

regularly clean by sweeping up debris and bagging for disposal.


1924-SPEC-020720 Page 16 of 49

Taking of

templates

Take all required measurements and templates of window opening, jamb,

mullion and cill profiles. Consider bar positions and take measurements to

calculate parallax compensations for the protective glazing layer.

Fabrication of

protective

glazing

New clear external protective glazing:

Manufacture protective glazing panels to suit existing stone window

surrounds made from clear Glashütte Lamberts restauro glass and milled

lead. Alternative glasses may be used by agreement of client, architect and

other stakeholders. Provide new bronze saddle bars, matching sizes of

saddle bars to stained glass panels,

Design of leadwork setting out for each window to be as set out in the

Schedule of Works.

The head and tracery shapes are to be in full panes but may be divided at

critical stress points presented by the tracery shapes.

The protective glazing is to be leaded with perimeter cames in 5/8″ flat profile

with ½″ uneven & U lead divisions and 3/16″ break leads within the tracery

shapes.

Prior to leading protective glazing, allow for a bead of neutral curing silicone

to be run along the heart of the perimeter came before inserting the sheets.

The protective glazing cames to be hand sealed after the silicone has cured

with black linseed oil putty.

If lead condensate trays are scheduled to be provided, account for these

within new glazing panels.

Condensation

trays

Provide where instructed by the Schedule of Works.

Provide at each window cill bay in code 5 sand cast lead, with 35mm

upstand, dressing neatly into junctions with horizontal and vertical surfaces.

Provide 2 no. lead wedges to each light below the bottom edge came to

hold glazing panel above condensation groove.

Preparation on

site for

transportation

/Panel removal

Prepare panels for transportation by securing any fractured pieces that are

considered at risk by taping on the unpainted side with 3M Magic tape.

a) Prepare suitable identification labels and attach to the support bars

prior to removal.

b) Prior to removal, cut through the copper wire ties from around the

support bars of each panel and fold back.

c) Ease perimeter lead cames and carefully remove the glazing from the

openings.

d) Snip off the excess copper wire ties to as near to the soldered joint as

possible and ease back to avoid any damage from protruding points.

e) Set aside the removed panels in a safe and unobtrusive position on the

scaffolding on the secure racking.

f) In appropriate stages manually carry the removed panels from the

scaffolding. Store in temporary racking system ready for transportation to

the studio.


1924-SPEC-020720 Page 17 of 49

g) Chip out around the through bar pockets and carefully remove the

saddle bars from the stonework.

A conservation record sheet is to be attached with each panel and

tracery section. Specified documentation will be listed on the sheet

covering its period of treatment. Fill in each sheet with the specified

information required prior to studio treatment.

Each panel to be transported in suitable packing cases or glass rack. The

panels are to be packed in such a way to ensure that no packing is in

contact of the glass surfaces. Use Coroplast board for packing or

equivalent non-acidic board.

Transport window and through bar to studio for treatment.

Installation of

protective

glazing (within

existing stone

grooves)

Fix code 5 lead condensation trays with 35mm up-stand to the cills of the

window openings.

Fix the new protective glazing within the existing stone grooves.

The pointing of the protective glazing to be in hydraulic lime mortar or to

the architect’s specifications. The pointing must allow for possible structural

movement.

The lead condensation tray to be filled with aquarium gravel to a level

sufficient to prevent ingress of air from the exterior.

Cleaning of

plain glazing

All diamond quarry pattern plain glazing to be cleaned to both interior and

exterior sides.

Panels to be brushed down with soft brushes to remove surface dust and

cobwebs before swabbing with deionised water on microfibre cloths.

Studio Work

Assessment In the studio and prior to any conservation work each panel is to be

thoroughly assessed using binocular microscopes to ensure that no further

damage is caused during the cleaning process.

Post removal

photographic

recording

Photograph each panel on the light box in both transmitted and reflected

light conditions.

a) Additional detailed photographs are to be taken of areas of damage

or special interest.

b) The photographs are to be taken in a high resolution digital format. Each

photograph is to be named giving its window and panel number and filed

within folders for each window.

c) Three sets per window of the digital images are to be saved on CD or

DVD. Provide one set for the Client, one for the Architect and one for the

contracted conservation studio. Two complete sets of all the images are

to be downloaded onto external hard drives.

Condition

record -

rubbings

Make two sets of pre-conservation full size rubbings of each panel on detail

paper. One set as a re-leading working sheet and another as a record,

annotated with details listed with information detailed in the list of

abbreviations to be used on stained glass diagrams. (See Appendix 3)


1924-SPEC-020720 Page 18 of 49

a) Mark each rubbing with the following information across the top band

of each rubbing in a clear, readable manner.

1. Window number and panel number.

2. Measured full size of the panel.

3. A ruled marking strip to indicate scale details.

b) On completion of the re-leading take a post conservation rubbing and

annotate with details listed with information detailed in the list of

abbreviations to be used on stained glass diagrams.

Leading Re-leading of the panels is not required; however allow for the renewal of

damaged perimeter cames and others removed to undertake bonding

repairs to edge pieces.

Further interventions to be discussed and agreed on a panel by panel

basis. Such interventions may include, for example:

• Repair leads inserted during the last re-leading to have their leafs either

totally removed to expose the fine line of the came heart or pared back

to reduce the visual impact. The decision made by the conservator to

undertake these procedures must ensure that the glass pieces are held

mechanically within the main leadwork.

• Pieces that are star fractured or severely disfigured by the addition of

dense mending leads are to be repaired within the panels. Allow for either

partial dismantling of the panel to expose the repair pieces or remove the

face leaf to extract the pieces from the repair section. Repair disturbed

leading as found necessary after completing and reinstating the glass

repairs. Any necessary repair leads that are required are to be as fine as

practicable (1/8″ or less).

Sections of lead work disturbed during the process of repair are to be hand-

sealed with traditional black putty to the external came leaves only.

Stained Glass

repairs and

cleaning

Fractured pieces removed from the panels for repair are to be edge-

bonded where clean break edges are exposed with CAF3 silicone

adhesive or approved alternative silicone.

Multi-fractured bonded pieces not held mechanically by the lead came

or other mechanical methods are to be supported by a kiln-moulded 1mm

backing plate. The edges of the backing plate and the bonded pieces are

to be sealed with neutral curing silicone.

Cleaning of the glass surfaces should be carried out with the aid of

binocular microscopes. The suggested cleaning method may be applied

generally but it is important that the conservator overseeing the project

inspects each piece and makes considered judgements as to whether

swabbing is safe to undertake. If it is considered that the swabbing will

remove or damage the pigment, the cleaning of these pieces should be

restricted to light dusting down only.

The glass which only has light deposits of grime on the external surface is to

be cleaned by swabbing with deionised water. Further cleaning to remove

mortar splashes, heavier deposits of grime and deposits of corrosion may

be removed by light brushing with stiff bristle brushes or scalpels as found

necessary.


1924-SPEC-020720 Page 19 of 49

The internal painted surfaces are found with light deposits of dust and

cobwebs. The internal surface may be safely cleaned by first dusting down

with soft hair brushes to remove the light dust and cobwebs. The sooty

deposit can be removed by lightly patting the surface with cotton wool

swabs, dampened with deionised water. The addition of ethanol to

deionised water (50:50) may be employed to assist with the cleaning if

found necessary. (Note: no wiping action is permitted to clean the painted

surfaces).

Stained Glass

framing

Frame the main light stained glass panels to form unit sections in 10 x 12 x

2mm ‘U’ profile manganese bronze to the perimeters of each main light.

Tracery shapes with acute curves to be framed in 6 x 12 x 2mm ‘U’ profile

manganese bronze.

Fix flexible 1 x 10mm phosphor bronze fixing brackets with 4.5mm fixing

holes formed within them to the sides of the U section. The brackets to be

positioned at approximately 200-250mm intervals and secured to the U

section with solid copper rivets and soldered.

The division of the frames to be made in ½″ x ½″ x 1/16″ bronzed brass ‘T’

section to form a stacking method.

Cut new intermediate support bars in either ½″ x ¼″ or ⅜″ x ¼″ rectangular

section bronzed bar to match the profile and dimensions of the existing

support bars. The new bars to be soldered directly to the inner profile of the

‘U’ sections; alternatively mechanical joining methods may be employed.

Re-band the panels during assembly into the frames in tinned 3/16″ flat

copper strip.

Solder bracing plates across all joints of the framed sections; alternatively

mechanical joining methods may be employed.

Solder 1″ leaf lead light shields to the perimeters of the external face of the

framed sections.

Reinstallation of Stained glass

Transportation

from studio to

site

Each panel to be transported back to site in suitable packing cases for

glass and bronze frame. The panels are to be packed in such a way to

ensure that no packing is in contact of the glass surfaces.

Use Coroplast board for packing or equivalent non-acidic board.

Protect the components during transportation.

Reinstate

stained glass

panels

Offer the framed sections to the front face of the openings to determine

the best position whilst maintaining an equal gap to perimeter to allow

passage of airflow.

Drill the marked positions with a 6mm drill bit and insert a suitable stone

anchoring nylon plug, such as those produced by Fischer.

Screw the framed sections in position with brass, bronze, stainless steel or

other suitable non-ferrous screws.

Fold the leaf lead light shields down to the stonework to hide any side light

and ease open at appropriate positions to form small gaps to allow

adequate ventilation to top and bottom of each window opening.


1924-SPEC-020720 Page 20 of 49

STONEMASON

Materials

Stone generally Stone is to be sandstone or limestone, free from natural defects including

hairline fractures, quarried without the use of explosives and selected by the

quarry and stonemason for the use and position in which it will be

incorporated in the finished work.

All stone is to be selected, worked and marked so that it will be laid in position

in the building on its natural bed, except for copings, string courses, hood

moulds and tracery heads, where the stone bed must be perpendicular to

the weathered face, and voussoirs or arches where the bed shall be

perpendicular to the line of thrust.

Generally provide samples of new stone to match existing surface texture,

finish or special detail.

Limestone Clipsham from Stamford Stone Co., Swaddywell Quarry, Stamford Road,

Helpston PE6 7EL.

Note: Stone to be sourced from former Clipsham Quarry Company, Clipsham

Hall, Clipsham, Oakham, Rutland LE15 7SE; contractor to provide evidence

that material has been obtained from this quarry, not 'Medwells Quarry'.

Ironstone Supplier: The Great Tew Estate, The Estate Office, New Road, Great Tew,

Chipping Norton, Oxon OX7 4AH.

Cramps &

Dowels

All new work, repairs, rebuilt work are to be properly cramped and dowelled

together and to adjoining fabric.

Cramps and dowels are to be stainless steel or phosphor bronze

(specification PB102), purpose made and recommended by the

manufacturer for the particular application and site conditions.

Allow for careful removal of all existing iron cramps etc found in existing work

where repairs are being undertaken. Replace removed cramps etc with

stainless steel or phosphor bronze where necessary.

If old cramps cannot easily be removed without damaging adjacent

stonework, wire brush and treat with 2 coats Fertan Rust converter from:

Fertan UK, King & Queen House, High Street, Hamble, SO31 4HA

Tel 02380 456600, Email [email protected]

Workmanship

General The work is to be carried out by qualified stonemasons working for an

approved stonemasonry contractor.

Identification Arrange review inspection with Architect before starting work. Confirm

type and extent of work required.

Mark identified stones clearly, but not indelibly, on face of masonry units or

parts of units to be cut out and replaced and cross-reference to drawings/

photographs.

Before starting work, use measurements and photographs as appropriate

to record bonding patterns, joint widths, special features, etc.

mailto:[email protected]


1924-SPEC-020720 Page 21 of 49

No stone shall be ordered until the stone for replacement has been

identified on site by the Architect who reserves the right to substitute repairs

for replacement of selected stones.

The stonemason is responsible for taking his own site dimensions and making

his own templates and preparing stonework and shop drawings. Shop

drawings to be submitted to the Architect for approval.

Piece Repairs

Where string courses and hoodmoulds are to be piece repaired, the specialist

stonemason is to cut the existing stone back by a minimum depth of 125mm

to a square surface, and dowel and glue the new stone to the remaining

existing stone.

The Architect may give directions for complete replacement if the depth of

existing stones in the wall is less than 200mm.

All piece repairs to weathering surfaces are to be cut under existing flintwork

or stonework by a minimum of 75mm to prevent rain penetrating behind

repairs.

All adhesive used is to be acrylic resin recommended for masonry work by

the manufacturers, such as Sebralit Solid or equal approved, and used strictly

in accordance with the manufacturer’s recommendations.

In connection with stonework repairs allow for all cutting out, numbering of

stones etc, removal of glazing/louvres etc where appropriate and for refitting

same after work complete.

Resin pinning

fractured stone

Use Acrylic resin for piecing in and fixing cramps, bar reinforcement,

armatures etc. Manufacturer and reference: Sebralit Solid

Pins to be Stairib 460 Deformed Round Bar 6mm diameter in Grade 18/8

Austenitic Stainless Steel 460 Nmm². By George Clark (Sheffield) Ltd or similar

supplier approved by the CA.

Mortar Repairs

generally

The stone mixture is to be in a 3:1 mix aggregate: lime. The defective stone is

to be cut back to a firm base drilled and laced with stainless steel wire or

grade 316 pins to provide a skeleton framework for the repairs. The wire must

not come closer than 25mm (1”) to the finished stone surface. Where

necessary polyester adhesives are used to hold the armature in place.

Masonry joints are to be retained in the finished repair and the mix adjusted

to match the existing stone in colour and texture, without using cement

colourings. Where repair is too shallow for an armature, key by drilling into the

stone and wet surface before applying the lime mortars.

Mortar Repairs

application

Pre-clean all retained work to match surrounding cleaned work.

Carry out consolidation as agreed on site with the Architect.

Friable stone faces to be descaled and defrassed. Undercut top edges to

protect feather edges from weather and to vertical and bottom edges

provide slurry/mortar repair to discourage ingress of water.

The area to be repaired should be well wetted and particularly friable stone

should be treated with 3 coats of slurry mix.

Water is added to this mix to achieve a thin creamy consistency.


1924-SPEC-020720 Page 22 of 49

Brush on the slurry coat and work well into the stone. Allow to tack dry before

applying second and third slightly thicker coats.

Repair mortar should be as dry as possible. Repair mortar to be applied using

small trowels and spatulas to a depth of no more than 12mm per application.

Repairs to be tended between applications, and each stage allowed to go

off to a leathery consistency but still green before application of the next coat

Repairs to be tapped by hand to establish any areas of failure. Each stage

must be sound before work can continue.

Repairs to be kept damp and protected from frost, wind and direct sunlight

to prevent rapid drying out and subsequent cracking, shrinking, and failure.

Use damp hessian as protection. Particular attention needs to be paid to

overnight protection.

Modelling, finish and texture of repairs: care to be taken over final tending

and finishing off. Texture repairs to match adjacent stonework by working

over with hessian, spatulas, plaster modelling and sculpture tools to the

approval of the Architect.

Redundant

fittings/fixtures

Remove all redundant fixtures and fixings and make good with lime mortar

unless otherwise specified. Minimize disturbance to surrounding surfaces.

Where identified, fill hole with lime mortar; for apertures larger than 50x50mm

piece in stone to match adjacent.

Repointing

Mortar Mixes Shall be generally 1:2.5 lime: sand or stonedust as specified. Pozzolanic

materials are to be used where specified. Other specifications of mortars

are to be used where specified.

For ashlar pointing and bedding use 1:3 mix.

Lime To be St Astier NHL 3.5 Hydraulic Lime (NHL 5 for copings or other exposed

locations and NHL 2.0 for ashlar walling and dressings or repair mortar slurry

coat).

Sand Shall be washed coarse, sharp sand from a local source approved by

Architect, complying with the relevant provisions of BS1199.

Aggregate must be added to the sand to improve match with the existing

material. Aggregate may be obtained from natural sands, gravels, brick,

shells, chalk or flint as appropriate. Existing original mortars are to be crushed

and examined to check contents of original aggregate and are to be

matched as much as possible.

Water Water must be clean, fresh and from the piped main.

Mixing Mortar must be carefully batched, gauged and mixed in accordance with

best current practice. Additives shall not be used. Whenever possible

coarse stuff must be left for minimum 24 hours before gauging with cement.

Mixing shall preferably be carried out by one man to produce consistent

results.

Lime putty should be made and stored in the traditional way and left for a

minimum of 24 hours to fatten up.


1924-SPEC-020720 Page 23 of 49

All bricks shall be well buttered with mortar before being laid with all joints

flushed up as the work proceeds. Bricks with frogs to be laid frog up.

Facework shall be kept perfectly clean and no rubbing down will be

allowed.

Adverse

weather

Do not bed masonry units or repoint in air temperatures:

• In cement gauged mortars when at or below 3°C and falling or unless

it is at least 1°C and rising (unless mortar has a temperature of not less

than 4°C when laid and the masonry is thoroughly protected)

• In hydraulic lime:sand mortars when at or below 5°C and falling or

unless it is at least 3°C and rising

• In nonhydraulic lime:sand mortars in cold weather without approval

Temperature of the work: Maintain above freezing until mortar has fully set.

Rain and snow: Protect masonry by covering during precipitation and at all

times when work is not proceeding.

Hot conditions and drying winds: Prevent masonry from drying out too rapidly.

Newly placed or pointed work shall be protected where necessary from

damage by night frost and drying effects of sun and wind with sacking or

canvas frames applied to wall surfaces. Protect all newly repaired/erected

work from inclement weather for minimum of seven days after completion.

New mortar damaged by frost: Rake out and replace.

Trial Areas Allow for trial areas of repointing for the Architect’s approval before

general repointing work proceeds.

Biocide for

Vegetable

Growth

Brush off all loose moss and lichen growth and apply Murasol 20 by

Cementone Beaver, or equal approved, in accordance with the

manufacturer’s instructions. Allow minimum 48 hours between completion

of treatment and repointing.

Masonry joint

treatment

Carefully rake out loose and open joints to a sound surface backing (twice

the thickness of the joint but minimum depth of 35 mm), wet and repoint using

a 1:3 lime:sand or stone dust as specified. Joints to be flush but feather edging

of mortar must be avoided by recessing the joint slightly as necessary. Finish

joints flush with a rag, stick or brush.

For wide joints with coarse aggregate mortar the joints should be stippled with

a bristle brush to roughen the surface and tighten the joints.

Finish joints ensuring consistency of colour, texture, profile, and overall

appearance to match the existing surrounding mortar.

Set joint face flush with the face of stonework unless:

• this is at difference with the existing surrounding mortar, and/or

• the joints are very wide or arises are broken; and/or

• the Architect instructs otherwise.

Where masonry arises are eroded, set joint face further back, but avoiding

the creation of ledges, which may trap or hold water.


1924-SPEC-020720 Page 24 of 49

Grouting of

Voids in Existing

Structures

Grout mixes may contain constituents from the following list and mix designs

will be agreed on site:

Water, fine sand, lime, pulverised fuel ash (PFA), polyester resin.

Minor grouting operations of surface fractures, cracks and minor voids will

usually be carried out using traditional hand/gravity methods. More detailed

guidance is available from the Architect.

Where larger scale grouting operations are specified the Contractor shall

engage a suitable specialist subcontractor experienced in the type of work

to be undertaken. The specialist subcontractor will be required to make

detailed proposals for the materials, technique and procedures to be used

in the grouting operations for the design team’s approval. The Contractor

must consult his subcontractor before submitting his tender and shall include

a statement of method of grouting, proposed to be adopted, with his tender.

The tender price for grouting must clearly show the breakdown of cost

between the specialist’s price and the main Contractor’s work in connection

with grouting, attendance etc.

In all grouting operations there will be the following general requirements:

a) Provide constant supervision and monitoring for leaks of water and grout,

structural movement etc. Provide all temporary works.

b) Keep accurate records showing volumes, mixes and pressures of water

and grout used at each injection point. Copies of these records to be

provided for the Architect and Engineer as soon as possible after each

section of grouting.

c) Allow for all building work and materials in connection with preparation for

grouting and making good wall faces after and for cleaning off all grout

stains etc. In gravity grouting operations allow for raising all materials to

suitable level above grouting injection points.

d) Flush out with clean water to remove loose material and thoroughly wet

voids.

e) Ensure that 100% grouting is being achieved by constantly checking results

and regrouting as necessary.

SCAFFOLDER

Health & Safety Contractors must comply with the Health and Safety at Work etc Act 1974,

the Management of Health and Safety at Work Regulations 1999, the Work

at Height Regulations 2005 and the Construction (Design and

Management) (CDM) Regulations 2015. Access and working scaffolds

should be designed, constructed and used in accordance with BS EN

12811-1 Temporary works equipment. Scaffolds. Performance requirements

and general design. Method statements, where required, from the

scaffolding subcontractor for the purpose of the Construction Phase Plan

should be submitted to the Principal Contractor, well in advance of the

commencement date. No change from an approved method should be

permitted without a written agreement clearly stipulating the changes. The


1924-SPEC-020720 Page 25 of 49

Principal Contractor is responsible for safety standards during erecting and

dismantling of scaffolds.

Structural

Requirements

To comply with the Working at Height regulations 2005, all scaffolds must

be assembled to NASC Technical Guidance TG20:13 Good Practice

Guidance for Tube and Fitting Scaffolding or be designed by bespoke

calculation, by a competent person to ensure it will have adequate

strength rigidity and stability while it is erected , used and dismantled. All

scaffold designs must be engineered in accordance with the most up to

date British Standards, Codes of Practice and other guidance notes.

Temporary Roofs

& Sheeting

Temporary roofs should be designed to resist wind uplift forces. Their

supporting structure will therefore have to be held down. It is essential to

ensure that where holding force is derived from kentledge, anchors or

connections to a sufficient mass of masonry, the holding devices and

connections to them are in place and effective before roofing sheets and

site sheets, if used, are installed. Use of water filled drums for kentledge

should be avoided due to possible leakage, freezing or vandalism. Roof

coverings should generally be new galvanise steel corrugated sheeting,

fixed with special clips to avoid drilling through tops of corrugation. Include

adequate method of disposal of rainwater from temporary roofs. Sheeting

to be 2500mm high solid boarding with entrance gates as necessary,

painted in colour to be agreed with the Architect.

Fixings & Ties Fixings and ties are not allowed except with the express approval of the

Employer and the Architect. Where metal sockets are agreed and left for

future maintenance, they must be of stainless steel, grade 304 or other non-

ferrous material.

Subcontractor’s

Design

It will be the overall responsibility of the Principal Contractor to plan, manage,

monitor and co-ordinate health and safety during construction. Allow for fire

precautions, security, access, safety areas, buttressing, lighting protection etc

together with criteria common to all designs such as design wind speed and

snow loading.

The Principal Contractor will be responsible for ascertaining the requirements

of all sub-contractors including the use of each platform, the number to be

fully boarded, those to be fully boarded, those to be sheeted, location and

purpose of hoists, fans, hoardings, loading bases and the length of time it will

be in position, together with other relevant information.

The Principal Contractor be responsible for obtaining a documented design

with calculations for the erection, use and dismantling of the scaffold

structure and for the integration of these activities within the overall work

programme. It is the duty of the Principal Contractor to check the design.

The Principal Contractor is to submit details of the following, when requested

to do so:

a) design

b) full set of drawings

c) calculations

d) number and location of working levels

e) loading bays

f) manufacturer’s details for specialist equipment such as ladder beams etc.

g) method statement covering erection, use and dismantling.


1924-SPEC-020720 Page 26 of 49

In certain cases, before work starts, there will be an independent check by a

competent person.

Control of Work

on Site

Notwithstanding the overall responsibilities of the Principal Contractor for

site activities and health and safety, adequate supervision must be

provided by the scaffolding subcontractor at all times during erection and

dismantling of scaffolding and temporary structures. All scaffolds and

structures should be inspected at least every seven days (and after

weather conditions likely to have affected their strength or stability) by a

competent person. Records of such inspections together with necessary

action must be made and signed by the person making the inspection. No

alterations must be made at any time without written authority from the

Architect. Any proposed modification or alteration that takes a scaffold

outside the scope of a generally recognised standard configuration should

be designed by a competent person and proven by calculation. At all

times during erection, dismantling or alteration to scaffold structures,

access to the working areas needs to be clearly defined by suitable barriers

and notices. Notices warning ‘incomplete scaffold’ should be secured as

necessary in an appropriate place. Stop all work on external scaffolding

during a thunderstorm.

Ensure that the scaffold is erected early enough and/or dismantled late

enough and has sufficient boards in place to suit the programmes of all

subcontractors and the Architect’s inspection programme.

Historic Buildings The Principal Contractor is to alert the scaffolding subcontractor that the

building is of historic importance and any damage whatsoever is

unacceptable. Extreme care is to be taken during erection and

dismantling and the work is to be supervised by a competent person.

Protection Tubes bearing on masonry should be provided with suitable timber bearers.

Against leadwork, felt or other material suitable packing should be used

between the timber and leadwork. Scaffold tube ends which are likely to

come into contact with the fabric of the building during erection,

dismantling or as a consequence of lateral movement should be provided

with plastic end caps. All putlogs to be kept at least 50mm away from the

building and fitted with plastic end caps. All scaffolding and temporary

structures must be adequately earthed against lightning strikes.

All scaffolding and temporary structures must be adequately earthed against

lightning strikes.

Public Access During erection, modification or dismantling, care must be taken to exclude

the public from a clearly defined area around the work. Authorised access

thoroughfares must have effective protection in the form of fans, netting,

sheetings, brickguards etc to protect persons from falling objects.

Ladders and tower scaffolds must not be left unattended when accessible

to the public.

Ladders at ground floor level and other risk areas and tower scaffolds must

be removed and securely locked away at the end of each working day.


1924-SPEC-020720 Page 27 of 49

SCHEDULE OF WORKS

ITEM DESCRIPTION COST (£)

1.0 General Notes

1.1 Brief History

The following is an excerpt from Appendix 3, The York Glaziers Trust

Report and Condition Advice 2017:

Browne’s Hospital in Broad Street, Stamford, was founded by William

Browne, merchant of the Calais Staple, and his wife Margaret, for the

relief of 12 paupers of the town. The buildings were completed by 1475,

and extensively restored in 1870. After William and Margaret’s deaths in

1489, the management of the hospital passed to Margaret’s brother,

Thomas Stokke, canon of York and rector of nearby Easton-on-the-Hill.

New letters patent were issued, and the chapel was dedicated on 22

December 1494. Statutes for the management of the institution were

issued on 9 October 1495. Stokke gifted to the hospital its silver seal,

which bears his arms. Thomas Stokke’s rebus of a stork on its nest with

the inscription /+ me sped(e)/ appears in the stained glass of the

Chapel, the Entrance Passage and in the Audit Room.

The medieval stained glass is located in two windows in the south wall

of the Chapel (sII and sIII), in a single window in the Entrance Passage

(west window) and in three windows in the first floor Audit Room (nII, sII,

sIII). The glass has been the subject of two scholarly publications, which

have established its high historical and iconographical significance. The

chapel glazing has been dated to c.1475, with the glazing of the Audit

Room and Entrance Passage to the years after 1489.

By 1822 the glass throughout the Hospital was in a very poor state of

repair. It was restored in 1869, when some new glass was supplied (eg

chapel sII, panel 2c and Audit Room sIV). The glass was cleaned,

releaded and rearranged by G. King & Sons in 1967, with art historical

advice from Dr P A Newton and financial support from the Pilgrim Trust.

Overview of condition

The stained glass is structurally sound and in a stable condition.

However, deterioration due to environmental moisture is evident in the

form of widespread internal microcracking and discolouration of

glasses, pitting of the glass surfaces, and loss of fired paint pigment.

The stained glass in the Chapel and Audit Room is currently protected

by external wire guards, which are in good condition. The Entrance

Passage window has no external protection.

1.2 The glazier undertaking the specified works is to be ICON accredited to

the appropriate level for work on 15th-century stained glass. The glazier

is to provide with their tender a profile of the studio, which should

include details of all the team members who will be carrying out the

works including their level of experience, skills and accreditation.

1.3 Sub-contracting any part of the glazing package of works to another

specialist glazing studio is not permitted.


1924-SPEC-020720 Page 28 of 49

1.4 All aspects of the work to the stained glass should follow the CVMA

guidelines for conservation.

1.5 The glazing contractor is to provide a perimeter pointing sample for the

Architect’s consideration and approval prior to repointing the glazing

panels. The pointing sample is to be prepared to a 1000mm long section

internally and externally and is to be carried out in the approved

hydraulic lime mortar mix. Subject to the Architect’s approval, the

pointing sample may be retained as part of the works. Allow to rake out

as necessary.

The perimeter pointing to the glazing can be carried out by either a

skilled mason or the glazing contractor. Any more extensive perimeter

pointing and flaunching required is to be carried out by a skilled mason.

1.6 The desired goals of the project are:

• The documentation and recording of the stained glass and

conservation materials and procedures

• The cleaning of both sides of the stained glass in a conservative

manner so as not to damage or lose the existing painted detail

• The stabilization of the stained glass panels, retaining the existing

lead work

• Improvements to the appearance by the reduction of mending

leads

• The environmental protection of the stained glass through the

construction of a purpose-made bronze frame with support bars

• The in-situ cleaning of the existing diamond quarry glazing

accessible during the conservation and environmental

protection works

1.7 It is crucial that the proposals are addressed on a window by window basis

to limit the impact of the EPG. Exactly how the impact of the EPG is

mitigated is for the selected glass conservators to work up during the

tender process. The overall view of the south elevation of the Hospital from

Broad Street, and internal views of the windows in the chapel and the

Audit room will also be important considerations for the glass conservator

in the details of the final proposals.

It is intended that the glass conservator will include their own thoughts and

proposals on detailing and positioning of the EPG with their tender return.

1.8 Documentation and recording required and produced should broadly

follow the Guidelines of The Churches Building Council:

https://www.churchofengland.org/sites/default/files/2018-

12/CCB_Conservation-reports.pdf

2.0 General Preliminaries

2.1 Allow for all preliminaries, access equipment, temporary works and

protection.

2.2 Protect all parts of the existing fabric of the building from damage

during the works. Minimise dust and noise during the works. Clear away

https://www.churchofengland.org/sites/default/files/2018-12/CCB_Conservation-reports.pdf

https://www.churchofengland.org/sites/default/files/2018-12/CCB_Conservation-reports.pdf


1924-SPEC-020720 Page 29 of 49

debris and surplus materials as it accumulates. Specifically protect

adjacent windows and historic joinery.

2.3 Comply with all CDM regulations. Develop the Health & Safety plan and

compile a Health & Safety File.

2.4 Keep the site safe and secure during the works and out of hours. Stored

materials should be secured out of hours.

2.5 Electricity and water are available on site. Maintain, alter and adapt

temporary works as necessary. The contractor should provide suitable

on site welfare facilities.

The client is willing for contractors to use a wc and kitchenette within

the Hospital, to be designated for their sole use during the works.

2.6 Minimise dust and noise during the works.

2.7 The site is to be a no smoking and no radios site.

2.8 Great care must be taken to keep roads and paths safe and clean of

debris. Contractor parking, deliveries to site, plant and the storage of

materials must be carefully considered in relation to other road and

path users and suitable allowances made.

There is no onsite parking. Some parking spaces may be able to be

coned off roadside at the front of the building with agreement from the

County Council.

2.9 All proprietary products and materials to be employed in accordance

with the manufacturer’s recommendations, codes of practice, etc and

good conservation practice.

2.10 Read the architect’s specification and drawings together and allow for

all parts of the work shown and described.

2.11 Liaise with the Curator over keys, times of working, cleaning up for

services, access, location of welfare facilities etc.

2.12 Following completion of the works the contractor must ensure that road

ways and paths are returned to the condition they were in prior to the

work commencing. Leave the works clean and tidy on completion.

2.13 Prior to commencement of the works undertake dilapidation

photographs, cross referenced to the plan and issue to the Architect

and Client electronically via USB stick each.

2.14 Labour

The Contractor shall insert hourly rates and/or percentages as below

and shall include the total within the tender sum. The inserted rates and

percentages shall remain fixed for the duration of the contract.

A. Building labour (unskilled) 5 x £ _________ =

B. Building labour (skilled) 5 x £ _________ =

Note: The Contractor must complete both (A) & (B) above.


1924-SPEC-020720 Page 30 of 49

2.15 Material & Goods

C. Include the sum of £100 for materials and goods.

D. Add % for incidental costs, overheads and profit _______%.

2.16 Rates (do not include within tender sum)

Indicate here for Main Contractor’s % rate for profit and attendance on

sub-contractors __________%.

Indicate extra over cost for lime repointing of 1m length £________ __.

2.17 Contingencies

Allow a provisional sum of £5,000 for contingencies, to be expended at

the direction of the Architect.

£5,000.00

3.0 Scaffolding

3.1 Erect and maintain access scaffolding necessary to complete the

specified works to undertake sizes and templates, removal of wire

guards, removal of panels, installation of protective glazing, cleaning of

plain glazing, reinstallation of wire guards and reinstallation of stained

glass. To be in accordance with the requirements set out within the

Project Preliminaries, current Health & Safety and British Standards.

3.2 For any areas of permanent external scaffolding where required,

provide new 3 metre high metal sheet fencing to bottom of each fixed

scaffold to enclose the working area, provided with a secure access

door which is to be locked at the end of each working day.

Contractor to supply a scaffolding alarm system for any permanent

scaffolding, with telephone call out to suit client requirements.

3.3 Indicate here weekly hire cost for scaffolding if contract period is

extended £______ ____ (do not include within tender sum).

4.0 Chapel windows sII and sIII

4.1 All works items are to be in accordance with Specification Leaded Light

Glazing trade clauses.

4.2 Issues and constraints

The majority of the stained glass is in Chapel window sII. There is limited

stained glass in the tracery only of sIII.

The clear leaded light quarries to sIII are to be left insitu. The external

wire guards are in good condition and are to be retained.

The glazing conservator is to mitigate the impact of the EPG through

considering the type of glass, leading pattern design, method of

framing and positioning of the EPG and the original window.

The EPG for the stained glass in sII needs to be considered in conjunction

with the clear leaded light window of sIII in terms of internal and external

views and positioning of the EPG. Following discussions with Historic


1924-SPEC-020720 Page 31 of 49

England’s specialist advisor, consideration is to be given to installing the

stained glass framed panels of sII on the same line as the existing clear

glazing of sIII with the new outer protective glazing to sII to be fitted

between the stained glass line and the external window guard line. See

sketch diagram 1924/104. Careful consideration to be given to

potential fixing methods for the EPG if not using the existing glazing

groove.

Standard tender to be returned on that basis.

Alternative tender price to be submitted with tender return if glazing

conservator wishes to propose an alternative approach.

See photos 01-08.

4.3 Undertake in-situ photographic record and inspection of glazing, take

sizes and templates.

4.4 Provisionally allow to produce mock up of potential solution(s) to be set

up and viewed and agreed with all key stakeholders on site before full

fabrication – read with 4.3 below.

4.5 Fabricate new code 5 lead condensation trays and outer protective

glazing as Specification.

Following discussions with Historic England’s specialist advisor,

consideration to be given to providing outer protected glazing as

diamond quarry glazing, reflecting the largely diamond quarry glazing

to window sIII and to historic buildings on other side of Broad Street.




4.6 Return to site to temporarily remove existing wire guards, remove

stained glass panels, install lead condensation trays and new outer

protective glazing, and reinstall wire guards externally, renewing fixings

with stainless steel clips and screws as may be necessary.

4.7 Clean diamond quarry glazing to window sIII in-situ.

4.8 Undertake studio works to stained glass: recording, leading, glass repairs

and cleaning, all as Specification.

4.9 Frame stained glass panels as Specification.

4.10 Return to site and reinstall framed stained glass.

4.11 Supply copies of all in-situ, pre and post conservation documentation

and photographic records to client and architect.

4.12 Masonry repairs

Allow provisional sum of £1000 to undertake minor areas of lime mortar

consolidation repair of window stonework. To be agreed on site once

scaffold is in place.

£1,000.00


1924-SPEC-020720 Page 32 of 49

5.0 Audit Room windows sII, sIII, sIV




The medieval stained glass in the Audit Room is located in the upper

sections of each window.

The lower sections are modern clear leaded light diamond quarries

which are to be left insitu. There are opening casements in the lower

right plain glazed section of Audit Room windows sII and sIV.

The external wire guards are in good condition and are to be retained.




The EPG for the stained glass to Audit Room windows sII, sIII, sIV needs

to be considered in conjunction with Chapel windows of sII and sIII in

terms of overall external views and positioning of the EPG. Following

discussions with Historic England’s specialist advisor, consideration is to

be given to installing the stained glass framed panels on the same line

as existing, to maintain a continuous glazing line viewed internally with

the quarry glazing below, with the new outer protective glazing to be

fitted between the stained glass line and the external window guard

line. See sketch diagram 1924/104. Careful consideration to be given to

potential fixing methods for the EPG if not using the existing glazing

groove.




See photos 09-14.



5.4 Provisionally allow to produce mock up of potential solution(s) to be set

up and viewed and agreed with all key stakeholders on site before full

fabrication – read with 4.2, 4.3 and 5.3 below.





diamond quarry glazing, reflecting the diamond quarry glazing to the

lower window sections and to historic buildings on other side of Broad

Street.





1924-SPEC-020720 Page 33 of 49


stained glass panels, install lead condensation trays and new outer

protective glazing, and reinstall wire guards externally, renewing fixings

with stainless steel clips and screws as may be necessary.

5.7 Clean diamond quarry glazing to all windows in-situ.

Ease opening lights and ensure they are left in working order.









consolidation repair and pinning of fractured window stonework. To be

agreed on site once scaffold is in place.

£1,500.00

6.0 Audit Room window nII




The medieval stained glass in Audit Room nII is located in the tracery

section A1 only.

The remaining lower sections are modern clear leaded light diamond

quarries which are to be left insitu. There is an opening casement in the

lower right plain glazed section.

The external wire guards are in good condition and are to be retained.



framing and positioning of the EPG and the original tracery glazing.

See photo 15.


sizes and template for tracery section A1.

6.4 Fabricate new outer protective glazing for tracery section A1 as

Specification.


tracery section A1, install new outer protective glazing, and reinstall wire

guards externally, renewing fixings with stainless steel clips and screws

as may be necessary.


1924-SPEC-020720 Page 34 of 49

6.6 Clean diamond quarry glazing in-situ.

Ease opening light and ensure it is left in working order.

6.7 Undertake studio works: recording, leading, glass repairs and cleaning

of tracery section A1.

6.8 Frame tracery section A1 as Specification.

6.9 Return to site and reinstall framed tracery section A1.



7.0 Entrance Passage window (un-numbered – EPW)




The medieval stained glass in the Entrance Passge is in the middle two

of the four main lights, and in all four tracery sections.

The sections of clear leaded light diamond quarries are to be left insitu.

The Entrance Passage window has no external protection.




The EPG for the Entrance Passage window needs to be considered in

conjunction with the clear leaded light glazing sections in terms of

overall external views and positioning of the EPG. Following discussions

with Historic England’s specialist advisor, consideration is to be given to

installing the stained glass framed panels on the same line as existing,

to maintain a continuous glazing line viewed internally with the quarry

glazing, with the new outer protective glazing to be fitted between the

stained glass line and the external window guard line. See sketch

diagram 1924/104. Careful consideration to be given to potential fixing

methods for the EPG if not using the existing glazing groove.




See photos 16-19.







diamond quarry glazing, reflecting the diamond quarry glazing to the


1924-SPEC-020720 Page 35 of 49

lower window sections and to historic buildings on other side of Broad

Street.




7.5 Return to site to remove stained glass panels, install lead condensation

trays and new outer protective glazing.

7.6 Provide new external window guards to all lights.

Type/material: Stainless steel wire guards (as approved by Historic

England)

Size/gauge: 12 gauge with a 75mm (vertical) x 12mm (horizontal) pitch

with a 6mm frame all round.

Finish: Powder coated black.

Fixing: Black powder coated stainless steel clips fixed into mortar joints with

black coated / Japanned stainless steel screws.

Other requirements: Protections to be located between mullions / tracery

ie. to each bay, not in front of frame.

Provide a sample panel for Architect's approval prior to works

commencing on site, if approved this may be incorporated as part of the

works.

7.7 Clean diamond quarry glazing in-situ.









consolidation repair of window stonework. To be agreed on site once

scaffold is in place.

£500.00


1924-SPEC-020720 Page 36 of 49

COLLECTION PAGE

COST (£)

1.0 General Notes

2.0 General Preliminaries

3.0 Scaffolding

4.0 Chapel windows sII and sIII

5.0 Audit Room windows sII, sIII, sIV

6.0 Audit Room window nII

7.0 Entrance Passage window

8.0 Other Preliminaries not included in Schedule of Works

9.0 Profit and Attendance

10.0 Any works not included in items above

Total of Tender (excluding VAT)


1924-SPEC-020720 Page 37 of 49

APPENDIX 1: PHOTOGRAPHS

Photo 1: internal view of Chapel window sII and

part of sIII

Photo 2: Chapel window sIII stained glass tracery

Photo 3: Chapel window sII upper section Photo 4: Chapel window sII lower section


1924-SPEC-020720 Page 38 of 49

Photo 5: Chapel window sIII tracery stained glass

Photo 6: Chapel window sII external with guards Photo 7: Chapel window sII external close up


1924-SPEC-020720 Page 39 of 49

Photo 8: internal view of Stained glass to Chapel sII


1924-SPEC-020720 Page 40 of 49

Photo 9: overall view of Audit Room windows sII, sIII, sIV

Photo 10: Audit Room window sII – 2a, 2b and A1


1924-SPEC-020720 Page 41 of 49

Photo 11: Audit Room window sIII – 2a, 2b and A1


1924-SPEC-020720 Page 42 of 49

Photo 12: Audit Room window sIV – 2a, 2b and A1

Photo 13: Plastic Masonry repairs needed to Audit Room Photo 14: Pinned Masonry repairs needed to Audit Room


1924-SPEC-020720 Page 43 of 49

Photo 15: Audit Room nII – A1

Photo 16: Entrance Passage – extent of stained glass


1924-SPEC-020720 Page 44 of 49

Photo 17: Entrance Passage – tracery detail

Photo 18: Entrance Passage window side-on view Photo 19: Entrance Passage – detail of mullion and cill


1924-SPEC-020720 Page 45 of 49

Photo 20: Hospital viewed along Broad St from the west Photo 21: Hospital viewed along Broad St from the east

Photo 22: Hospital viewed across Broad St from the south


1924-SPEC-020720 Page 46 of 49

APPENDIX 2: CVMA NUMBERING SYSTEM


1924-SPEC-020720 Page 47 of 49

APPENDIX 3: LIST OF ABBREVIATIONS TO BE USED ON STAINED GLASS DIAGRAMS

Cracks Indicate with dotted lines used in conjunction with M, Pi, Po, or Ps to denote

application

Ea Edge joined by adhesive – specify in written record

Eb Edge joined by copper foil

L Leaf lead or strap lead

F Artificial filling – specify in written record

P Previous repairs or insertions

Gr Glass installed reversed – specify in written record if previous or new

Gu Re-used glass newly inserted (state source if known)

T Pieces transferred within panel or window (state previous location)

M Modern glass newly inserted

Pi Plated on front (inside)

Po Plated on back (outside)

Ps Plated on both sides

If plating is tinted or coloured, ‘t’ may be added

A New paint pigments (fired)

New painted areas are only permitted on plating or new glass.

Pc Paint consolidation – specify in written record

Please add other symbols if necessary, for individual projects.

Note

Submitted diagrams must be printed large enough to enable them to read easily.

The purpose of this diagram is to provide factual information on work included in the current

programme of conservation, rather than an assessment of the date of every piece of glass in

the window. Art historical observations that can be gained only whilst the glass is on the

bench should nevertheless be recorded.


1924-SPEC-020720 Page 48 of 49

APPENDIX 4: FORM OF TENDER


1924-SPEC-020720 Page 49 of 49

FORM OF TENDER

Project: 1924 Browne’s Hospital: Stained Glass Conservation

This tender is to be delivered to the office of Stephanie Norris Architects Ltd within a sealed

envelope and must arrive by 4pm on XXXX August 2020.

Facsimile copies will not be accepted.

I/We having read the Conditions Of Contract, Specification and drawings delivered to us and

having visited the site and inspected the proposed works, do hereby offer to execute the

whole of the works in accordance with those Documents including Provisional Sums and

Contingencies for the sum of:

______________________________________________________________________________

__________________________________________ (£ p) exclusive of VAT

I/We undertake, in the event of your acceptance, to execute with your client a form of

contract embodying all the conditions and terms contained in the offer to the reasonable

satisfaction of the Architects: Stephanie Norris Architects Ltd, 8 The Coppice, Impington

Cambridge CB24 9PP

I/We agree that should obvious errors in pricing or arithmetical errors be discovered in the

specification submitted by me/us before acceptance of this offer, that these errors will be

dealt with in accordance with the Alternative 1, contained in Section 6 of the NJCC ‘Code of

Procedure for Single Stage Selective Tendering’ 1996.

I/We understand that I am/we are tendering at my/our expense and that neither the lowest,

nor any other tender will necessarily be accepted.

Alternative contract period if requested in the Specification: ______________________________

Alternative start date if requested in the Specification: ___________________________________

Date this _____________________ day of _______________________________ 20__________

Signed: ______________________________________ Role in Company: ___________________

For and on behalf of: ______________________________________________________________

Address: _______________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

Telephone No: _____________________________ Fax No: _____________________________

E-mail Address: _________________________________________________________________