Agrément Certificate 2008/348 - Agrément South Africa€¦ · Agrément Certificate 2008/348 : ... and quality management documentation. ... manage the quality management system

Agrément Certificate 2008/348: Izoblok Building System Page 1 of 21

Copyright © Agrément South Africa, October 2008

The master copy of this document appears on the website: www.agrement.co.za

Validity

Users of any Agrément certificate should check its status: all currently valid certificates are listed on the website. In addition, check whether the certificate is Active or Inactive.

The certificate holder is in possession of a confirmation certificate attesting to his/her status.

PO Box 395, Pretoria 0001

Telephone: 012 841 3708

Fax: 012 841 2539

Email : [email protected]

Web : www.agrement.co.za/

Subject:

IZOBLOK BUILDING SYSTEM

Certificate holder:

Meeting of Minds cc 22 Ireland Road, Pietermaritzburg

KwaZulu-Natal 3201

Telephone: 033 260 6268 Fax: 033 260 6150

&

Infraset a Business unit of Aveng (Africa) Ltd

PO Box 751752 Garden View 2047

Power Street, Industries West, Germiston

Telephone: 011 876 5538 Fax: 011 872 1713

Use

The certificate covers the use of the Izoblok Building System for single and double storey building structures in all areas of South Africa for occupancy classes set out below (SANS 10400 table 1, regulation A(20)(1)):

• Places of instruction (A3)

• Worship (A4)

• Moderate and low-risk commercial service buildings (B2 and B3)

• Exhibition hall (C1)

• Moderate and low-risk industrials buildings (D2 and D3)

Agrément Certificate 2008/348

Quick guide

Contents page 4

Preamble page 5

Conditions of certification page 6

Assessment page 8

Technical description page 12

SANS 10400 The application of the National Building Regulations

Agrément Certificate 2008/348:Izoblok Building System Page 2 of 21

• Other institutional (residential) (E3)

• Shops and wholesaler’s store (F1, F2 and F3)

• Offices (G1)

• Hotel and dormitory (HI and H2)

• Domestic residence (H3)

• Dwelling house (H4)

The certificate and Agrément South Africa assessment apply only to the Izoblok Building System designed and constructed as described and illustrated in this certificate, and where the terms and conditions of certification are complied with.

General description

The Izoblok Building System is constructed under the supervision of a professional engineer or approved competent person who:

• Prepares a rational design that :

o ensures the structural integrity of the entire building

o adheres to the conditions of certification of this certificate and the certificate holders’ specification and quality management documentation.

The Izoblok Building System uses walls made of hollow ribbed wood/cement blocks that are filled with concrete. The foundation and roof are conventional. The blocks function as permanent shuttering and insulation material. At the ground-floor level the walls are constructed in a conventional manner with a damp proof course. The blocks are laid in stretcher bond, four courses at a time. Vertical alignment of inner ribs assists in placing of concrete fill and its compaction. Concrete (15 MPa) is cast into the block cavities, compacted and allowed to cure. Care is taken to maintain the stability of the blocks during the concrete casting. The walls (internal and external) are finished on both sides with 12 mm thick cement/sand plaster and painted. In single storey and first-floor structures, reinforced concrete lintels or ring beams as per the engineer’s details, are formed over windows, doors, eaves and gable walls. In double storey structures the first-floor slab is the conventional reinforced concrete slab, designed and constructed as per the engineer’s details. Foundations and the surface bed are conventional and designed by a professional engineer or approved competent person. Roof construction is conventional timber roof trusses. Windows, doors and services are conventional.

Agrément Certificate 2008/ 348: Izoblok Building System Page 3 of 21

FIGURE 1: TYPICAL SECTION THROUGH FOUNDATION, EXTERNAL WALL AND ROOF STRUCTURE


CONTENTS

PREAMBLE

PART 1: CONDITIONS OF CERTIFICATION

PART 2: ASSESSMENT

Scope of assessment

The assessment

Compliance with the National Building Regulations

Table 1: Performance

Table 2: Habitability

Table 3: Quality management system

PART 3: TECHNICAL SPECIFICATION

General description

Wood/cement blocks

Erection

Installation of service ducts

Plaster and finishes


PREAMBLE The certificate is issued by Agrément South Africa in terms of the powers granted to it by the Minister of Public Works. The certificate:

• has been granted after a technical appraisal of the performance of the Izoblok Building System for the uses covered by the certificate

• is independent of any patent rights that may or may not subsist in the subject of the certificate, and

• does not relieve the certificate holder from the obligation to obtain prior approval of the building authority concerned for the use of the subject.

Agrément South Africa considers that the quality and performance of the Izoblok Building System will be satisfactory provided that the requirements stipulated in the certificate are adhered to. However, Agrément South Africa does not on behalf of itself, or the state, or any of its employees or agents guarantee such quality or performance.

Responsibility for compliance with the requirements of the certificate and the quality of the finished buildings resides with the certificate holder.

No action for damages, or any other claim whatsoever, lies against Agrément South Africa, its members, the state or any of its employees should the said components and materials fail to comply with the standard set out in the certificate.

Building authorities or users who are in any doubt about any details or variation, should contact Agrément South Africa.

The validity of the certificate is reviewed every three years. The certificate shall remain valid as long as Agrément South Africa is satisfied that:

• the certificate holder complies with the general and specific conditions of certification and the technical requirements stipulated in the certificate

• the performance-in-use of the building system is acceptable

• any changes in building legislation, regulations, relevant standards or Agrément performance criteria have not invalidated the technical assessment, which formed the basis of certification.

Agrément South Africa reserves the right to withdraw the certificate at any time, should reasonable cause exist.

Notices affecting the validity of this certificate will be published in the Government Gazette.


PART 1: CONDITIONS OF CERTIFICATION

The Izoblok Building System described in this certificate must:

• be constructed by the certificate holder or a licensee

• be constructed in accordance with the technical description (see Part 3) and the certificate holder’s detailed specifications and quality management system

• comply with the Conditions of Certification.


• prepares a rational design that :


o adheres to the conditions of certification of this certificate and the certificate holders’ specifications and quality management documentation.

Any person required to check on details of construction shall refer to the documentation listed above, which are available from the certificate holder.

The Izoblok Building System is a combination of innovative and conventional construction. A change to any one aspect could result in one or more of the other aspects no longer complying with Agrément South Africa’s performance criteria. For these reasons, no change may be made to the Izoblok Building System as described and illustrated in this certificate unless such change is approved in writing by Agrément South Africa before it is implemented.

General conditions

Marking

A plaque of at least 100 x 75 mm, with Agrément South Africa’s identification logo together with the number of this certificate, as depicted, must be fixed at an appropriate position to an external wall of all the Izoblok Building System buildings.

Reappraisal

• Must be requested by the certificate holder before making changes to the building system

• Will be required by Agrement South Africa if there are changes to the National Building Regulations or to Agrement criteria

• Will be required by Agrement South Africa if the wood/cement blocks are locally manufactured.

The certificate may be withdrawn if the certificate holder or a registered licensee fails to comply with these requirements.

Licensee - any person or company appointed by the certificate holder and registered with Agrément South Africa to construct the Izoblok Building System in accordance with this certificate and authorised by him/her to claim compliance with the certificate. It is the certificate holder’s responsibility to ensure that the licensee carries out the works in compliance with this certificate and in accordance with the approved quality system.

Izoblok Building System

Tested and approved fit for purpose when constructed as

specified in

CERTIFICATE 2008/348


Validity

The continued validity of the certificate is subject to a satisfactory review by Agrément South Africa every three years.

Quality monitoring

The certificate holder is required to participate in Agrément South Africa’s post-certification quality management scheme, which requires:

• that the certificate holder shall continue to implement and manage the quality management system approved by Agrément South Africa in the assessment of the Izoblok Building System

• the co-operation of the certificate holder in facilitating post-certification quality monitoring by Agrément South Africa or its authorised agents.

Requirements of Supplement to certificates that must be met

The Supplement to certificates: good building practice (revised 2001) applies to those conventional aspects of the Izoblok Building System that have not been specifically assessed (see Part 2: Scope of assessment on next page). Cognisance should be taken of the recommendations contained in the Supplement to certificates to ensure that an acceptable standard of construction is maintained consistently.

On behalf of the Board of Agrément South Africa

Signed

Chairperson 22 October 2008


PART 2: ASSESSMENT

Scope of assessment

The assessment applies to those innovative aspects of the Izoblok Building System described in Part 3 of the certificate. It also applies to those conventional aspects of the building system which, in the opinion of Agrément South Africa, are influenced by the innovative aspects. The innovative aspects referred to is the use of hollow ribbed wood/cement blocks as permanent shuttering to concrete walls in buildings.

The assessment

In the opinion of Agrément South Africa, the Izoblok Building System as described in the certificate is suitable for use for occupancy class types specified (page 1).

The performance-in-use of buildings erected with this system will be such that it will satisfy:

• the relevant requirements for safety and health prescribed by Agrément South Africa

• where stated in Table 1, the requirements of the National Building Regulations

• Agrément South Africa’s performance criteria and requirements for durability and habitability.

The detailed comments on the assessment are set out in Tables 1, 2 and 3 below. Each aspect of performance was assessed by experts in that field.

Compliance with National Building Regulations

The innovative aspects of the Izoblok Building System that relate to the National Building Regulations are as set out in Table 1. Any regulation not specifically referred to is considered to be outside the scope of the certificate and must be applied by the local authority in the normal manner.

The conventional aspects of the construction are subject to the rules of good building practice (typically as described and

illustrated in Agrément South Africa’s Supplement to certificates and in the Home building manual Parts 1, 2 and 3 issued by the National Home Builders Registration Council), and must comply with the National Building Regulations.

For details see Agrément South Africa’s Assessment criteria: building and walling systems.

Republic of South Africa. National Building Regulations, Government Notice R. 2378, Government Gazette No 12780, Pretoria, South Africa, 12 October 1990


Table 1: Safety and health

Aspects of performance

Opinion of Agrément South Africa

National Building Regulations satisfied

Fitness-for-purpose of materials used

The quality and suitability of the materials as described in Part 3 meet the requirements of the regulations

Regulation A13(1)(a) Materials

Behaviour in fire Satisfactory: The 150 mm thick Izoblok walls are classified as non-combustible (type FR) with a fire rating of 90 minutes. The building system can be used for single and double storey attached and detached applications, including fire separating or division separating elements up to 90 minutes.

K4 walls

T1(1)(b) and (c) and insofar as the walls are concerned are satisfied.

Comments made in Supplement to certificates must be taken into account when building plans are scrutinised by local authorities to check compliance with Regulations T1(1)(a), T1(1)(d) with regard to spread of smoke, and T1(1)(e).

Deemed-to-satisfy rules TT5.1(c) and TT5.2 (c) of Section 3 of SANS 10400 have been met.

Structural strength and stability

Satisfactory: Provided the technical specification as described in Part 3 of this certificate are adhered to.

K1, K3 and K4 Wall

L1 (a) and (b) Roof

Regulations B 1 (1) and (2) are deemed to be satisfied. The structural design of each building is the responsibility of a professional engineer or a proved competent person and deemed-to-satisfy rule BB4 of SANS 10400 is applicable.

Regulations H1(1) and (2)), Foundations, are deemed to be satisfied as follows:

H1(1) on non-problematic soils; H1(2) in all buildings where foundations are designed by a professional engineer or approved competent person and deemed-to-satisfy rule HH1(a) applies.

Water penetration and rising damp

Satisfactory: Izoblok Building System meet Agrément South Africa’s criteria for resistance to rainwater penetration and rising damp throughout South Africa.

K2 Walls

J1(4) Floors


Table 2: Habitability



Explanatory notes

Thermal performance and energy usage

Satisfactory: When compared to Agrément Standard Brick House

The maximum temperatures in summer in the Izoblok Building System insulated ceiling will be less.

The energy required to heat dwelling units constructed of the Izoblok Building System with insulated ceiling in winter will be considerably less than that required for a standard brick house.

Agrément South Africa’s opinion is based on the calculated likely maximum indoor air temperature in summer in a 53 m2 Izoblok Building System in Cape Town, Durban and Johannesburg, and the calculated energy required to maintain an indoor temperature of 160 in winter in Cape Town and Johannesburg.

When assessing the thermal performance of a dwelling, the calculated performance of the subject is compared with that of the standard brick house. This is of similar size, orientation and fenestration as the Izoblok Building System and has:

• external walls of 230 mm brick and internal walls of 110 mm brickwork

• plastered internal wall surfaces

• a concrete floor

• a sheeted roof that is fitted with a ceiling without insulation.

Condensation Satisfactory: The Izoblok building System with insulated ceiling performs better than the Agrément Standard Brick House

Condensation is generally a problem in the Southern Coastal Condensation Problem Area (SCCP Area). The assessment of this aspect of performance applies only to dwellings in this area. Agrément South Africa requires that the minimum standard of performance be equivalent to that of the standard brick dwelling, which is itself not immune to condensation problems.

Acoustic Satisfactory: Agrément South Africa’s performance criteria for sound attenuation between adjacent rooms and between adjacent dwellings have been met.

Agrément South Africa opinion is based on computer simulation. The in situ airborne sound insulation that is likely to be obtained between adjacent rooms 53 dB for 200 mm load-bearing partition walls and 51 dB for 150 mm non-load bearing internal walls.

These values meet Agrément South Africa’s criteria and most of the recommended sound insulation values set out in SANS 10218: Part 1

A description of the degree of acoustic privacy that can be expected between specific rooms for various degrees of sound insulation is given in Supplement to certificates.

SANS 10218: Part 1: Acoustic properties of buildings


Table 2: Habitability (continued)

Durability

Satisfactory: Provided water penetration and rising damp are adequately prevented and normal use and adequate and regular maintenance are applied.

Agrément South Africa’s opinion is based on the knowledge of the materials used and on inspection of buildings constructed using Izoblok Building System

Note that in much of South Africa, suitable plaster sand is not readily available. As high quality sand is critical to durability aspects of this system, it may be necessary to blend sands. Provided proper attention is paid to the quality and grading of the sand and adequate curing of plaster durability will be acceptable. The Izoblok Building System should not require more frequent repairs than the conventional plastered brick house. Hairline cracks may appear but these should not be of major concern as they have no structural significance. Water will not penetrate to the inside of the building, nor will the Izobloks deteriorate. Should plastered areas be damaged, these can be readily repaired (see Part 3)

Table 3: Quality management



Explanatory notes

Quality management

System

The certificate holder’s quality management system complies with Agrement South Africa’s requirements. If properly applied, it will ensure that quality in design and construction of the Izoblok Building Systems will be consistently maintained.

Agrement South Africa’s requirements are based on SANS 9001

SANS 9001: Quality management systems – Requirements’


PART 3: TECHNICAL SPECIFICATION

3.1 General description


• prepares a rational design that :


o adheres to the conditions of certification of this certificate and the certificate holder’s specifications and quality management documentation

The Izoblok Building System uses walls made of hollow ribbed wood/cement blocks that are filled with concrete. The foundation and roof are conventional. The blocks function as permanent shuttering and insulation material. At the ground-floor level the walls are constructed in a conventional manner with a damp proof course. The blocks are laid in stretcher bond, four courses at a time. Vertical alignment of inner ribs assists in placing of concrete fill and its compaction. Concrete (15 MPa) is cast into the block cavities, compacted and allowed to cure. Care is taken to maintain the stability of the blocks during the concrete casting. The walls (internal and external) are finished on both sides with 12 mm thick cement/sand plaster and painted. In single storey and first-floor structures reinforced concrete lintels or ring beams as per the engineer’s detail are formed over windows, doors, eaves and gable walls. In double storey structures the first-floor slab is the conventional reinforced concrete slab, designed and constructed as per the engineer’s details. Foundations and the surface bed are conventional and designed by a professional engineer or approved competent person. Roof construction is conventional timber roof trusses. Windows, doors and services are conventional.

3.2 The wood/cement blocks

The wood / cement blocks (figure 6 ) are manufactured in the Czech Republic in compliance with Austrian Specification ÖNORM B 3208. In addition the blocks are manufactured in accordance with the European guideline ETAG 009 issued by the European Organisation for Technical Approvals – EOTA. The typical block sizes are 1000 mm long x 250 mm high x 200 mm wide (minimum) for exterior walls and 1 000 x 250 x 150 mm for the interior walls.

The raw materials for the manufacture of the Izoblok blocks are:

• wood chips and sawdust (up to 20 % by mass maximum), preferably from softwood

• ordinary Portland cement type I or II


• fly-ash optional up to 20 % replacement level of cement

• aluminium sulphate as the accelerator (and compatibility enhancer)

Wood chips and sawdust are mixed and fed into a hammer mill to achieve fibres of suitable size and conveyed into storage bins. The wood fibres are mixed together with cement, fly-ash, aluminium sulphate solution and water in a batch concrete mixer of a suitable type (e.g. pan or horizontal rotor mixers) in suitable ratios and blended evenly. The mix is conveyed into the block-making machine that is specifically modified for production of wood/cement blocks. After the initial seven day cure the blocks are accurately machined into the applicable sizes. The blocks are further cured and stored on pallets for an additional three weeks and are then ready for use.

3.3 Foundations and surface bed

The Izoblok Building System uses conventional foundations (figure 2 ). A competent person classifies the site in accordance with the site class designation set out in table 3 of the South African Institute of Engineering Geologists (SAIGE) publication titled Guidelines for Urban Engineering and Geological Investigations. Foundations are always designed by a professional engineer in accordance with the requirements of SANS 10161 and constructed accordingly. In normal ground conditions (site class designation H and R) two types of foundation design can typically be used:

o Cast in situ concrete surface bed with thickened edge beam (figure 2b and 2c)

o Conventional concrete strip footing and foundation walls (figure 2a).

A damp-proof membrane in accordance with SANS 952 or one covered by a valid Agrément certificate is laid on the compacted fill under the surface bed and taken under the external walls. The surface bed is 85 mm thick (minimum) cast in situ concrete with a minimum compressive strength of 15 MPa at 28 days when screeded and 25 MPa when power floated. When specified, weld-mesh reinforcing is incorporated in the surface bed. Cement used is either CEM 1 or CEM IIA and meets the requirements of SANS 50197-1.

3.4 Erection

The surface beds immediately below all walls are provided with a damp proofing course in a conventional manner. The blocks are laid in stretcher bond, four courses at a time and filled with concrete. Concrete 15 MPa is considered generally adequate for single and double storey structures in accordance with the requirements of SANS 10400, Part K table 2. The consistency of concrete is such that it flows and fills the cavities in all directions (vertical and horizontal) freely. The concrete is compacted with

SANS 10161: The design of foundations for buildings

SANS 952: Polyolefin film for damp and waterproofing in buildings

SANS 50197-1: Cement Part composition, specifications and conformity criteria for common cements


suitable vibrating equipments or by hand with a wooden slat and allowed to cure. Care is taken to maintain the stability of the blocks during concreting. The walls (internal and external) are plastered with 12 mm thick cement/sand mortar on both faces. To achieve satisfactory integrity partition walls are connected to the outer wall in the following two methods (figure 3 ):

• Cutting a slot in the inner face of the block corresponding to the width of the inner walls to facilitate insertion

• Use of suitable metal ties or reinforcing bars to connect the block ends of the inner walls to the outer wall.

In single storey and first-floor structures reinforced concrete lintels are formed over windows and doors to spread the load to the adjacent walls. In double storey buildings the structural elements are designed and constructed as per the engineer’s details. At the top of the wall, at roof level, a ring beam is formed.

Standard pre-cast concrete lintels suitably dimensioned are used or lintels are cast in situ using the wood/cement blocks as per the engineer’s details. In the case of pre-cast lintels, the ends should be inserted into the cavities of the adjacent wood/cement wall blocks and concreted. In case of casting the lintels on site, reinforcing steel determined by the engineer (usually 2Y10 reinforcing bars) are placed into the block rebates and the blocks closed off and supported by shuttering boards from below and concreted. The bars should be of sufficient length, so as to ensure adequate anchorage (usually 750 mm over the size of the opening at the top and 300 mm at the bottom on each end) in the adjacent wall sections. The lintels are formed by concrete fill (figures 4 and 5).

3.5 Installation of service ducts

For the installation of service ducts that are thinner than the thickness of the sides of wood/cement blocks, slots can be cut or milled directly with suitable wood cutting tools (e.g. small chain saw), after the concrete fill has hardened sufficiently. When service ducts of greater depth than the block face thickness are required, the following procedure is recommended:

• Place an insert (from wood or polystyrene) of suitable dimensions and with slightly sloped side edges into the vertical cavity of the wall prior to pouring of concrete. The broader face of the insert should be in contact with the inner face of the block wall on the side from which the duct is to be accessed. After the concrete fill has hardened, the wood/cement wall is cut so that the insert can be removed. The dimensions of ducts formed like this should be taken into consideration in the design to compensate for potential effect on the strength and integrity of the formed concrete wall.


3.6 Plaster and finishes

To perform properly, the plaster should adhere to the blocks and any cracking or other defects must be prevented. The sand for the plaster should comply with the requirements set out in SANS 1090 and the cement should be CEM I 42.5 or CEM II 32.5, mixed in ratios of 1:5 to 1:8. The plaster must be applied by experienced plasterers and suitably protected by painting. The plaster must be properly cured (time and methods to depend on the specific regions in South Africa) before painting. The surface of the walls must be adequately firm and dry, without loose particles or dust, prior to plastering. The core concrete must be properly bonded with the wood/cement blocks; a minimum of 28 days is essential to attain the desired strength. The actual drying of the walls may however take a much longer time to cure.

Prior to plastering of the walls, the roof structure and all the internal walls, door and window frames must be installed and the service installations fixed in place in order to prevent any damage to the plaster due to any additional modifications that might be necessary. In dry or windy weather and air temperatures above +20oC, the plaster must be cured for at least five days after the application, protected against direct sunlight and wind in order to prevent cracking due to quick drying.

SANS 1090: Aggregates from natural sources – Fine aggregates for plaster and mortar







Documents

Agrément Certificate 2008/348 - Agrément South Africa€¦ · Agrément Certificate 2008/348 : ... and quality management documentation. ... manage the quality management system