Electronic Copy - RIBA Product Selector · 2005-06-30 · In the opinion of the British Board of Agrément, Catnic Cavity Wall Ties and Insulation Retaining Clips are satisfactory

Readers are advised to check the validity of this Certificate by either referring to the Index of Current BBA Publications or contactingthe BBA direct (Telephone Hotline 01923 665400).

Catnic LimitedPontygwindy EstateCaerphillyMid-Glamorgan CF8 2WJTel: 01222 885955

AgrémentCertificate

No 91/2690

Designated by Governmentto issue

European TechnicalApprovals

CATNIC CAVITY WALL TIES AND INSULATION RETAINING CLIPSChaînage pour murs à pariosWandanker

Product Building Regulations

• THIS CERTIFICATE REPLACESCERTIFICATE No 88/1985AND RELATES TO CATNICCAVITY WALL TIES ANDINSULATION RETAININGCLIPS.• Catnic Cavity Wall Ties aremanufactured from stainlesssteel and the insulationretaining clips are injectionmoulded from thermoplasticpolymers.• BS 1243 : 1978 relates tocavity wall ties but does notcontain the full specification ofproducts known to be fit fortheir purpose.

1 The Building Regulations (England and Wales)

The Secretary of State has agreed with the British Board of Agrèmentthe requirements of the Building Regulations to which wall ties cancontribute in achieving compliance. In the opinion of the BBA, the

position of Catnic Cavity Wall Ties and Insulation Retaining Clips, if used inaccordance with the provisions of this Certificate, is as stated in Detail Sheet 1.

2 The Building Standards (Scotland) Regulations

In the opinion of the BBA, the position of Catnic Cavity Wall Ties andInsulation Retaining Clips under these Regulations, if used inaccordance with the provisions of this Certificate, is as stated in Detail

Sheet 1.

3 The Building Regulations (Northern Ireland)

In the opinion of the BBA, the position of Catnic Cavity Wall Ties andInsulation Retaining Clips, if used in accordance with the provisions ofthis Certificate, is as stated in Detail Sheet 1.

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In the opinion of the British Board of Agrément, Catnic Cavity Wall Ties and Insulation RetainingClips are satisfactory if used as set out in this Certificate. Certificate No 91/2690 is accordinglyawarded to Catnic Limited.

On behalf of the British Board of Agrément

Date of issue: 28th October 1991 Director

Recreated in QX 12.1.01 (SM)

Conditions of Certification

4 Conditions4.1 The quality of materials and the method ofmanufacture have been examined and foundsatisfactory by the BBA and must be maintained tothis standard during the period of validity of thisCertificate. This Certificate will remain valid for anunlimited period provided that:

(a) the specification of the products is unchanged,and

(b) the manufacturer continues to have theproducts checked by the BBA.

4.2 Where reference is made in this Certificate toany Act of Parliament, Regulation made thereunder,Statutory Instrument, Code of Practice, BritishStandard, manufacturer's instruction or similarpublication, it shall be construed as reference tosuch publication in the form in which it is in force atthe date of this Certificate.

4.3 In granting this Certificate, the BBA makes norepresentation as to the presence or absence ofpatent rights subsisting in the products and/or as tothe legal right of Catnic Limited to market, install ormaintain the products.

4.4 It should be noted that any recommendationsrelating to the safe use of these products which arecontained or referred to in this Certificate are theminimum standards required to be met when theproducts are used. They do not purport in any wayto re-state the requirements of the Health and Safetyat Work etc Act 1974, or of any other statutory orCommon Law duties of care, or of any duty of carewhich may in the future exist; nor is conformity withsuch recommendations to be taken as satisfying therequirements of the 1974 Act or of any otherpresent or future statutory or Common Law duties ofcare. In granting this Certificate, the BBA does notaccept responsibility to any person or body for anyloss or damage incurred in respect of personalinjury arising as a direct or indirect result of the useof these products.

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD25 9BAFax: 01923 665301

©1991 For technical or additionalinformation, tel: 01923 665300.For information about AgrémentCertificate validity and scope, tel:Hotline: 01923 665400

e-mail: [email protected]: www.bbacerts.co.uk

Electronic Copy

Readers are advised to check the validity of this Detail Sheet by either referring to the Index of Current BBA Publications or contactingthe BBA direct (Telephone Hotline 01923 665400).

1 The Building Regulations 1985 (as amended) (England and Wales)

The Secretary of State has agreed with the British Board of Agrément the requirements of the BuildingRegulations to which wall ties can contribute in achieving compliance. In the opinion of the BBA, CatnicCavity Wall Ties and Insulation Retaining Clips, if used in accordance with the provisions of this Certificate,

will contribute to meeting the relevant requirements.Requirement: A1 Loading

Comments: Where wall ties are relied on to contribute to the strength and stability of cavity walls in relation to windloading, the products are acceptable.

Requirement: Regulation 7 Materials and workmanship

Comments: Catnic Cavity Wall Ties and Insulation Retaining Clips are acceptable.In addition to the contribution which wall ties can make, as stated above, the following commentsapply:

Requirement: B3(1) Internal fire spread (structure)

Comments: When used in a masonry cavity wall Catnic Cavity Wall Ties will provide an equivalent performanceto that of butterfly ties to BS 1243 : 1978. Catnic timber frame ties are suitable for use in wallsrequiring a resistance to an internal fire of up to and including a half-hour, provided the requirementsgiven in section 7 of the relevant Detail Sheets are met.

Requirement: C4 Resistance to weather and ground moisture

Comments: When used in an external cavity wall Catnic Cavity Wall Ties will not adversely affect the resistance ofthe wall to the passage of moisture.

Requirement: E1 Airborne sound (walls)

Comments: The effect of wall ties on the resistance to airborne sound of cavity walls has not been assessed.Requirement: L1 Conservation of fuel and power

Comments: The effect of wall ties on the resistance to the transmission of heat of cavity walls has not beenassessed.

2 The Building Standards (Scotland) Regulations 1990

In the opinion of the BBA, the position of Catnic Cavity Wall Ties and Insulation Retaining Clips under theseRegulations, if used in accordance with the provisions of this Certificate, will satisfy or contribute to satisfyingthe various Regulations and Technical Standards as listed below.

Regulation: 10 Fitness of materialsStandard: B2 Selection and use of materials, fittings, components and other manufactured products

Comments: Catnic Cavity Wall Ties and Insulation Retaining Clips are acceptable.Regulation: 11 StructureStandard: C2.1 Construction

Comments: Where wall ties are relied on to contribute to the strength and stability of cavity walls in relation to windloading, the product is acceptable.

Regulation: 12 Structural fire precautionsStandard: D2.2 Fire resistance

Comments: When used in a masonry cavity wall Catnic Cavity Wall Ties will provide an equivalent performanceto that of butterfly ties to BS 1243 : 1978. Catnic timber frame ties are suitable for use in wallsrequiring a resistance to an internal fire of up to and including a half-hour.

Regulation: 17 Preparation of sites and resistance to moistureStandard: G3 Resistance to precipitation

Comments: When used in an external cavity wall the wall ties will not adversely affect the resistance of the wall tothe passage of moisture.

Regulation: 19 Resistance to transmission of soundStandard: H2.1 Airborne sound

Comments: The effect of the wall ties on the resistance to airborne sound of cavity walls has not been assessed.Regulation: 22 Conservation of fuel and powerStandard: J2 The building fabric

Comments: The effect of the wall ties on the resistance to the transmission of heat of cavity walls has not beenassessed.

Catnic Limited Certificate No 91/2690

DETAIL SHEET 1

Building Regulations

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CATNIC CAVITY WALL TIES AND INSULATONRETAINING CLIPS

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3 The Building Regulations (Northern Ireland) 1990 (as amended 1991)

In the opinion of the BBA, Catnic Cavity Wall Ties and Insulation Retaining Clips, if used in accordance withthe provisions of this Certificate, will satisfy the various Building Regulations as listed below.

Regulation: B2 Fitness of materials and workmanship

Comments: Catnic Cavity Wall Ties and Insulation Retaining Clips are acceptable.Regulation: C4 Resistance to ground moisture and weather

Comments: When used in an external cavity wall the wall ties will not adversely affect the resistance of the wall tothe passage of moisture.

Regulation: D3 Stability

Comments: Where wall ties are relied on to contribute to the strength and stability of cavity walls in relation to windloading, the product is acceptable.

Regulation: E5 Fire resistance of elements of structure

Comments: When used in a masonry cavity wall Catnic Cavity Wall Ties will provide an equivalent performance tothat of butterfly ties to BS 1243 : 1978. Catnic timber frame ties are suitable for use in walls requiring aresistance to an internal fire of up to and including a half-hour, provided the requirements given in section7 of the relevant Detail Sheets are met.

Regulation: F3 Maximum U values of walls, floors and roofs

Comments: The effect of the wall ties on the resistance to the transmission of heat of cavity walls has not beenassessed.

Regulation: G2 Sound insulation of dwellings - separating walls and separating floors

Comments: The effect of the wall ties on the resistance to airborne sound of cavity walls has not been assessed.




©1991 For technical or additionalinformation, tel: 01923 665300For information about AgrémentCertificate validity and scope, tel:Hotline: 01923 665400



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Technical Specification

1 Description1.1 Catnic Cavity Wall Ties Type BB-2 arefabricated from 0.6 mm nominal thicknessaustenitic stainless steel type 304S15 to BS 1449 :Part 2 : 1983 Steel plate, sheet and strip —Specification for stainless and heat-resisting steelplate, sheet and strip, by pressing from slit coil.

1.2 The ties are 191 mm long and 19 mm wide.The ends have tabs pressed in them to form mortarkeys. The centre portion is folded to form a rib andincorporates three drips to prevent the passage ofwater across the tie (see Figure 1). The ties arestamped with the manufacturer’s name and aremarked with the legend ‘top’ on the appropriatesurface.

Figure 1 Cavity wall tie type BB-2

1.3 The snap-on insulation retaining clips typesIRC 45, IRC 80 and IRC 85 are 45 mm, 80 mmand 85 mm in diameter respectively (see Figure 2).Types IRC 45 and IRC 80 are injection mouldedfrom low density polythene, and type IRC 85 frompolypropylene.

Figure 2 Insulation retaining clips

1.4 All the insulation retaining clips may be usedwith plastic foam thermal insulation boards and cliptypes IRC 80 and IRC 85 may also be used withmineral fibre batts.

1.5 Quality control on the ties includes checks onthe incoming steel for chemical composition,dimensional tolerances and mechanical properties.During manufacture regular visual and dimensionalchecks are made.

• THIS DETAIL SHEET RELATES TO CATNIC CAVITY WALL TIES TYPEBB-2 FOR TYING CAVITY WALLS.• The ties are suitable for use in masonry cavity walls comprising twoleaves of similar thickness in the range of 90 mm to 150 mm and with anominal cavity width of 50 mm where a butterfly tie to BS 1234 : 1978would be acceptable.• The ties are manufactured from stainless steel and available in one size.

Certificate No 91/2690

DETAIL SHEET 2

Catnic Limited

CATNIC CAVITY WALL TIES TYPE BB-2,INSULATION RETAINING CLIPS TYPESIRC 45, IRC 80 AND IRC 85

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1.6 The insulation retaining clips are bought in toCatnic Limited’s specification, and are subjected tovisual and dimensional quality control checks byCatnic Limited.

2 Delivery and site handling2.1 The ties and clips are delivered to site inquantities of 250. Ties are packed in boxes andthe clips are packed in clear polythene bags. Eachclip and box bears the BBA identification markincorporating the number of this Certificate.

2.2 The insulation retaining clips must be storedout of direct sunlight and must not be allowed tocome in contact with petrol, mineral oil, turpentineor similar products.

Design Data3.1 Catnic Cavity Wall Ties Type BB-2, whenused in accordance with this Detail Sheet, aresatisfactory for use in cavity walls in which butterflyties to BS 1243 : 1978 Specification for metal tiesfor cavity wall construction would be acceptable.

3.2 In addition to the requirements directlyreferred to in this Detail Sheet, structures ofbrickwork or blockwork in which the ties are

incorporated must be designed and/or constructedto comply with one of the following technicalspecifications:BS 5628 : Part 1 : 1978(1985) Code of practicefor use of masonry — Structural use of unreinforcedmasonry, and BS 5628 : Part 3 : 1985 Materialsand components, design and workmanship.

The Building Regulations 1985 (England andWales) (as amended), Approved Document A1/2,Section 1, Part C.

The Building Regulations (Northern Ireland) 1990(as amended 1991), Technical Booklet D Structureand the relevant British Standard.

3.3 The ties have been assessed as equivalent totype 2 ties as defined in BS Draft for DevelopmentDD140 : Part 2 : 1987 Wall ties —Recommendations for design of wall ties.

4 Practicability of installation4.1 The ties can be built easily into brickwork orblockwork during construction.

4.2 The clips can be fitted easily to the ties typeBB-2 and will effectively retain the thermalinsulation boards. Insulation retaining clip typeIRC 85 can also be fitted to 4 mm double triangleties to BS 1243 : 1978.

5 Structural performance5.1 The ties have been assessed as havingstrength properties at least equal to those ofbutterfly ties to BS 1243 : 1978. When correctlyembedded, the tensile strength of the tie exceeds itsresistance to pull-out from the mortar. In commonwith other ties used in masonry walls, it is importantto ensure correct embedment.

5.2 The ties are sufficiently flexible to allow in-plane differential movement of the two connectedleaves of masonry and also to allow site adjustmentfor differences in height between inner and outerleaves.

6 Weathertightness6.1 The ties are effective in preventing thetransmission of water across the cavity.

6.2 The ties must be installed with the correct sideup and to assist, the top surface of the wall tie isclearly marked.

7 Behaviour in relation to fire

7.1 The ties are non-combustible.7.2 The effectiveness in fire, of the installedwall ties, is assessed as being equivalent to

that of butterfly ties complying with BS 1243 :1978. Guidance on the fire resistance of wallsincorporating butterfly ties is given in BS 5628 :Part 3 : 1985. A cavity wall consisting of two100 mm thick leaves of brickwork or blockworkincorporating the ties will have a fire resistanceperiod of six hours when non-loadbearing, and atleast two hours when loadbearing.

8 Durability

The ties and insulation retaining discs, whenused in accordance with the requirements ofthis Certificate, should have a service life of

not less than 60 years. Their durability will not beimpaired by contact with conventional cavityinsulation materials or mortar admixtures.

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Installation

9 Procedure9.1 Catnic Cavity Wall Ties Type BB-2 must bebuilt into the bed joints of masonry to a minimumembedment length of 55 mm. Care must be takento place them horizontally or with a slight fall to theouter leaf of the wall.

9.2 The first run of ties should be laid as near aspossible to, though not directly on, the damp-proofcourse, and at a horizontal spacing of 450 mm.

9.3 Construction should then continue with the tiesspaced at 450 mm vertically and 900 mmhorizontally, the ties being staggered in successiverows. The spacing may be varied, when requiredby the relevant Building Regulations, Standards, orCodes of Practice referred to in section 3 of thisDetail Sheet, provided the number of ties per unitarea is not decreased.

9.4 The insulation board retaining clips aresnapped into position on the ties approximately inthe centre of the cavity, to suit the thickness of theinsulation board used.

9.5 The insulation board is placed behind theclips on the lower ties, laid against the inner leaf ofmasonry, and retained by pressing the discs on theupper row of ties against the board.

9.6 The boards should form a closely butt-jointedrun (see Figure 3).

Figure 3 Typical installation

9.7 The free edges of insulation boards, whichmay be present at window and door openings andat the top of walls and not effectively retained bythe wall ties and clips, should be secured to theinner masonry leaf using BBA approved fixings.

9.8 Normal precautions must be taken to preventmortar droppings and protrusions impairing thefunction of the drips.

Technical InvestigationsThe following is a summary of the technicalinvestigations carried out on Catnic Cavity WallTies Type BB-2 and Insulation Retaining ClipsIRC 45, IRC 80 and IRC 85.

10 TestsAs part of the assessment leading to the issue ofCertificate No 88/1985:(1) Tests were carried out on the ties type BB-2 toestablish:tensile strengthcompressive strengthresistance to pull-out of ties embedded in mortar

jointsdimensional accuracy.

(2) Tests were carried out on the insulationretaining clips IRC 45 and IRC 80 to establish:effectiveness against the passage of waterdimensional accuracy.

(3) The tests for compression and resistance topull-out of ties embedded in mortar joints wereconducted on unrestrained brick couplets,fabricated using mortar of designation (iv) toBS 5628 : Part 1 : 1978(1985) and BS 5628 :Part 3 : 1985.

(4) The characteristic strength of the ties wascompared to that of butterfly ties tested andassessed in a similar manner and was found to beat least equal in each respect.

(5) The manufacturing processes were examined,including the methods adopted for quality control,and details were obtained of the quality andcomposition of the materials used.

(6) An assessment was made of:behaviour in firepracticability of installationeffectiveness of the drips against the passage ofwater.

(7) Information relating to durability, corrosionresistance and compatibility with materials incontact was examined.

(8) Site visits were made to confirm thepracticability of installation of the ties and clips inconjunction with insulation boards.

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11 Further investigationsThe following investigations were carried out aspart of the assessment leading to the issue of thisDetail Sheet.

(1) The strength and rigidity of the ties werecompared with the of requirements of BS Draft forDevelopment DD140 : Part 2 : 1987, for a type 2tie and was assessed as equivalent to them inevery respect.

(2) Tests were carried out on the insulationretaining clip IRC 85 to establish:dimensional accuracypracticability of installation.

(3) An assessment was made of the quality andcomposition of the material used in the manufactureof the insulation retaining clip type IRC 85.







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1 Description1.1 Catnic Timber Frame Ties Type BT-2 arefabricated from 0.6 mm nominal thicknessaustenitic stainless steel type 304S15 toBS 1449 : Part 2 : 1983 Steel plate sheet andstrip — Specification for stainless and heat-resistingsteel plate, sheet and strip, by pressing from slitcoil.

1.2 The ties are 120 mm long and 19 mm widewith a 31 mm lug for connection to the timberframe. The tie at one end has raised tabs pressedto form mortar keys, the centre section is formedinto a rib with a drip to prevent the passage ofwater across the tie and the other end is a lugfolded through 90° incorporating a hole for nailfixing to a timber frame member (see Figure 1).Each tie is stamped with the manufacturer’s name.


Figure 1 Timber frame tie type BT-2

2 Delivery and site handlingThe ties are delivered to site in boxes of 250. Eachbox bears the BBA identification markincorporating the number of this Certificate.

• THIS DETAIL SHEET RELATES TO CATNIC TIMBER FRAME TIES TYPEBT02 FOR TYING CAVITY WALLS WITH A MASONRY LEAF AND ATIMBER LEAF.• The ties are suitable for use in cavity walls with a masonry outer leafand a structural timber inner leaf and having a nominal cavity width of50 mm.


DETAIL SHEET 3Catnic Limited

CATNIC TIMBER FRAME TIES TYPE BT-2

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Design Data

3 General3.1 Catnic Timber Frame Ties Type BT-2, whenused in accordance with this Detail Sheet, aresatisfactory for tying a brickwork or blockwork outerleaf to the structural timber framework of domesticdwellings or industrial/commercial buildings of upto two storeys.

3.2 In addition to the requirements directlyreferred to in this Detail Sheet, structures ofbrickwork or blockwork in which the ties are

incorporated must be designed and/or constructedto comply with one of the following technicalspecifications:BS 5268 : Part 2 : 1991 Structural use of timber— Code of practice for permissible stress design,materials and workmanship.

The Building Regulations 1985 (England andWales) (as amended), Approved Document A1/2,Section 1, Part C.

The Building Regulations (Northern Ireland) 1990(as amended 1991), Technical Booklet D Structureand the relevant British Standard.


4.2 As the timber studs are covered by sheathing,care is required to ensure that the ties are nailed tothe centre of the timber stud, eg marking the studline prior to fixing the ties.

5 Structural performanceThe ties, when installed at the appropriate densitygiven in Table 1 and bearing directly onto thestructural sheathing, are satisfactory for use inbuildings situated in areas of mainland UK wherethey are subjected to design wind speeds of 35,39, 43 and 50 ms–1, as defined in CP 3 :Chapter V : Part 2 : 1972 Code of basic data forthe design of buildings — Loading — Wind loads.

Table 1 Tie spacing

Design wind speed Tie density Tie spacing(ms–1) (ties per m2) (mm)

horizontal vertical

35 3.7 600 450

39 4.4 600 375

43 5.6 600 300

50 7.4 600 225

6 WeathertightnessThe ties are effective in preventing the transmissionof water across the cavity.

7 Behaviour in relation to fire7.1 The ties are non-combustible.

7.2 The external wall shown in Figure 2,incorporating the ties, is assessed as

capable of achieving a half-hour fire resistancewhen exposed to fire from the inside, if tested toBS 476 : Part 8 : 1972 Fire tests on buildingmaterials and structures — Test methods andcriteria for the fire resistance of elements of buildingconstruction. Where any other form of wallconstruction incorporating the ties is subject to fireresistance requirements, an appropriate assessmentor test must be carried out by a NationalMeasurement Accreditation Service (NAMAS)accredited laboratory for the test concerned.

7.3 The timber framework must be lined to givefire protection to the loadbearing studs, such thatthe stability requirements of BS 476 : Part 8 :1972 can be satisfied for the appropriate period.

Figure 2 Installation details

8 DurabilityWhen used in accordance with therequirements of this Certificate the ties shouldhave a service life of not less than 60 years.

Their durability will not be impaired by contact withconventional mortar admixtures or timberpreservative treatments.

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Installation

9 Procedure9.1 Catnic Timber Frame Ties Type BT-2 must bebuilt into the bed joints of masonry to a minimumembedment length of 55 mm. Care must be takento place them horizontally or with a slight fall to theouter leaf of the wall.

9.2 The ties must be nailed through the sheathingto the centre of the timber stud, using annularring-shanked austenitic stainless steel nails,3.35 mm diameter and 60 mm long, complyingwith BS 1554 : 1990 Specification for stainlessand heat-resisting steel round wire. The ties must beinstalled with the lug uppermost.

9.3 The ties must be spaced to give the density(ties per m2 given in Table 1, to suit the designwind speed as defined in CP 3 : Chapter V :Part 2 : 1972.


Technical Investigations

The following is a summary of the technicalinvestigations carried out on Catnic Timber FrameTies Type BT-2.

10 Tests10.1 As part of the assessment leading to theissue of Certificate No 88/1985, tests werecarried out to establish:tensile strengthcompressive strengthresistance to pull-out when embedded in mortar

jointsresistance to pull-out when nailed to timber framesthe effects on tensile and compressive strength due

to dryingshrinkage of the timber framedimensional accuracy.

10.2 The manufacturing processes wereexamined, including the methods adopted forquality control, and details were obtained of thequality and composition of the materials used.

10.3 An assessment was made of:behaviour in firepracticability of installationeffectiveness of the drips against the passage of

water.

10.4 Existing information relating to durability,corrosion resistance and compatibility withmaterials in contact was examined.

11 Further investigationsA review was made of the work carried out duringthe assessment leading to the issue of CertificateNo 88/1985.

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1 Description1.1 Catnic Cavity Wall Ties Types BW4 andBW2 are fabricated from 2.5 mm and 3.3 mmnominal diameter 18/8 austenitic stainless steelwire type 304 to BS 1554 : 1990, respectively.

1.2 The shape and dimensions of the ties are shownin Figure 1. Both types are available in two lengths:200 mm long for cavity widths of 50 mm to

75 mm (BW4/200 and BW2/200)225 mm long for cavity widths of 75 mm to

100 mm (BW4/225 and BW2/225).

1.3 The snap-on insulation retaining clip typeIRC 85 has a diameter of 85 mm (see Figure 2)and is injection moulded from polypropylene.

1.4 The insulation retaining clips are for use witheither plastic foam thermal insulation boards ormineral fibre batts.


1.6 The insulation retaining clips are bought in toCatnic Limited’s specification and are subjectedto visual and dimensional quality control checksby Catnic Limited.

Figure 1 Wall tie type BW4 or BW2

44

14 35

200 (BW4/200)or 225 (BW4/225)

64

2035

200 (BW2/200)or 225 (BW2/225)

all dimensions in millimetres

• THIS DETAIL SHEET REPLACES DETAIL SHEET 4 AND RELATES TOCATNIC CAVITY WALL TIES TYPES BW4 AND BW2 AND INSULATIONRETAINING CLIP TYPE IRC 85 FOR TYING CAVITY WALLS.• The ties are suitable for use in masonry cavity walls comprising twoleaves of similar thickness in the range of 90 mm to 150 mm.• The ties are manufactured from stainless steel in two lengths and twodiameters, for use in cavity walls with cavity widths of 50 mm to 75 mmor 75 mm to 100 mm.


DETAIL SHEET 5Catnic LimitedCATNIC CAVITY WALL TIES TYPES BW4AND BW2 AND INSULATION RETAININGCLIP TYPE IRC 85

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Figure 2 Clip type IRC 85

2 Delivery and site handling2.1 The ties and clips are delivered to site inquantities of either 25 or 250. Ties are packed inboxes and the clips are packed in clear polythenebags. Each clip and box bears the BBAidentification mark incorporating the number of thisCertificate.

2.2 The insulation retaining clips must be storedout of direct sunlight and must not be allowed tocome in contact with petrol, mineral oil, turpentineor similar products.

Design Data

3 GeneralIn addition to the requirements directlyreferred to in this Detail Sheet, structures ofbrickwork or blockwork in which the ties are

incorporated must be designed and/or constructedto comply with one of the following technicalspecifications:BS 5628 : Part 1 : 1992 and BS 5628 : Part 3 :

1985.The Building Regulations (England and Wales),

Approved Document A1/2, Section 1, Part C.The Building Regulations (Northern Ireland),

Technical Booklet D Structure and the relevantBritish Standard.


4.2 The insulation retaining clips can be fittedeasily to the cavity wall ties types BW4 and BW2,and 4 mm double triangle ties to BS 1243 :1978, and will effectively retain the thermalinsulation boards.

4.3 The ties are smooth, without sharp edges andare slender in plan such as to resist the collection ofmortar droppings.

5 Structural performance5.1 The ties type BW4/200 have been assessedas equivalent to type 4 ties, when used in 50 mmto 75 mm cavity walls up to 10 m high, as definedin DD 140 : Part 2 : 1987.

5.2 The ties type BW4/225 have been assessedas equivalent to type 4 ties when used in 75 mm to100 mm cavity walls up to 10 m high, as definedin DD 140 : Part 2 : 1987.

5.3 The ties types BW2/200 and BW2/225have been assessed as equivalent to type 2 tieswhen used in 50 mm to 75 mm and 75 mm to100 mm cavity walls of three storeys up to 15 mhigh, respectively, as defined in DD 140 : Part 2 :1987.

5.4 Where the ties are used in cavity walls of aheight greater than stated in paragraphs 5.1 to 5.3,they must be shown to have adequate performanceby the calculation method shown in Appendix B ofDD 140 : Part 2 : 1987. All such calculations mustbe carried out by or under direct supervision ofappropriately qualified persons in accordance withUK practice, conditions and Building Regulations.

5.5 The ties are sufficiently flexible to allow in-plane differential movement of the two connectedleaves of masonry and also to allow site adjustmentfor differences in height between inner and outerleaves; however, they must not be bent in amanner that redirects to the fall from the outer leaftowards the inner leaf.

6 WeathertightnessThe ties are effective in preventing the transmissionof water across the cavity.

7 Behaviour in relation to fire7.1 The ties are non-combustible.

7.2 The effectiveness in fire of the installed tiestypes BW4 and BW2 is assessed as beingequivalent to that of butterfly ties complying withBS 1243 : 1978. Guidance on the fire resistanceof walls incorporating butterfly ties is given inBS 5628 : Part 3 : 1985. A cavity wall consistingof two 100 mm leaves of brickwork or blockworkincorporating Catnic cavity wall ties will have a fireresistance period of six hours when non-loadbearing,and at least two hours when loadbearing.

85 mm

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8 DurabilityThe ties types BW4 and BW2 and insulationretaining clips type IRC 85, when used inaccordance with the requirements of this

Certificate, should have a service life of not lessthan 60 years. Their durability will not be impairedby contact with conventional cavity insulationmaterials or mortar admixtures.

Installation

9 Procedure9.1 Catnic cavity wall ties must be built into the bedjoints of masonry to a minimum embedment length of50 mm, care being taken to place them horizontallyor with a slight fall to the outer leaf of the wall.

9.2 The first run of ties should be laid as near aspossible to, though not directly on, the damp-proofcourse and at a horizontal spacing of 450 mm.

9.3 Construction should then continue with the tiesspaced at 450 mm vertically and 900 mmhorizontally and staggered in successive rows. Thespacing may be varied, when required by therelevant Building Regulations, Standards, or Codesof Practice referred to in section 3 of this DetailSheet, provided the number of ties per unit area isnot decreased.

9.4 The insulation board retaining clips aresnapped into position on the ties approximately inthe centre of the cavity, to suit the thickness of theinsulation board used.

9.5 The insulation board is placed behind theclips on the lower ties, laid against the inner leaf ofmasonry and retained by pressing the clips on theupper row of ties against the board.

9.6 The boards should form a closely butt-jointedrun (see Figure 3).

Figure 3 Typical installation

9.7 The free edges of insulation boards which maybe present at window and door openings and at thetop of walls, and which are not effectively retainedby the wall ties and clips, should be secured to theinner masonry leaf using BBA approved fixings.



The following is a summary of the technicalinvestigations carried out on Catnic Cavity WallTies Types BW4 and BW2 and InsulationRetaining Clip Type IRC 85.

10 Test10.1 Tests were carried out on ties types BW4and BW2 to establish:tensile strengthcompressive strengthresistance to pull-out of ties embedded in mortar

jointsdimensional accuracy.

10.2 The tests for compression and resistance topull-out of ties embedded in mortar joints wereconducted on precompressed (0.1 Nmm–2) brickcouplets, fabricated using mortar of designation (iv)to BS 5628 : Part 1 : 1992 and BS 5628 :Part 3 : 1985, in accordance with BS DD 140 :Part 1 : 1986.

10.3 The strength and rigidity characteristics ofCatnic Cavity Wall Ties Types BW4 and BW2 inrelation to the requirements of DD 140 : Part 2 :1987 are given in Table 1.

Table 1 Strength and rigidity characteristics

Tie type Cavity width DD 140 : Part 2(mm) requirements

BW4/200 50 to 75 type 4

BW4/225 75 to 100 type 4

BW2/200 50 to 75 type 2

BW2/225 75 to 100 type 2

10.4 Tests were carried out on the insulationretaining clip type IRC 85 to establish:dimensional accuracypracticability of installation.

10.5 An assessment was made of the quality andcomposition of the material used in the manufactureof the insulation retaining clip type IRC 85.

11 Other investigations11.1 The manufacturing processes wereexamined, including the methods adopted for

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Date of issue: 30th September 1997 Director

British Board of AgrémentP O Box No 195, Bucknalls LaneGarston, Watford, Herts WD2 7NGFax: 01923 662133


e-mail: [email protected]://www.bbacerts.co.uk

quality control, and details were obtained of thequality and composition of the material used.


water.


Bibliography

BS 1243 : 1978 Specification for metal ties forcavity wall constructionBS 1554 : 1990 Specification for stainless andheat-resisting steel round wireBS 5628 Code of practice for use of masonry

Part 1 : 1992 Structural use of unreinforced masonyPart 3 : 1985 Materials and components, designand workmanship

DD 140 Wall tiesPart 1 : 1986 Methods of test for mortar jointand timber frame connectionsPart 2 : 1987 Recommendations for design ofwall ties


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Readers are advised to check the validity of this Detail Sheet by either referring to the BBA’s website (www.bbacerts.co.uk) or contactingthe BBA direct (Telephone Hotline 01923 665400).


1 Description1.1 Catnic Timber Frame Ties Type BT2-4 arefabricated from 0.6 mm thick austenitic stainlesssteel to BS EN 10088-2 : 1995, grade 1.4301,1.4541, 1.4306, 1.4436 or 1.4435.

1.2 The ties are 120 mm long and 19 mm widewith a 23 mm lug for connection to the timberframe. The tie at one end has raised tabs pressedto form mortar keys, the centre section is formedinto a rib with a drip to prevent the passage ofwater across the tie and the other end is a lugfolded through 90° incorporating a hole for nailfixing to a timber frame member (see Figure 1).Each tie is stamped with the manufacturer’s name.

1.3 The ties are fixed to the timber frame with3.35 mm diameter by 50 mm long, austeniticstainless steel, grade equivalent to 1.4301 ofBS EN 10088-2 : 1995, annular ring-shank nails.


Figure 1 Timber frame tie type BT2-4

2 Delivery and site handlingThe ties and nails are delivered to site in boxes of250 each. Each box bears the BBA identificationmark incorporating the number of this Certificate.

• THIS DETAIL SHEET RELATES TO CATNIC TIMBER FRAME TIES TYPEBT2-4 FOR TYING CAVITY WALLS WITH A MASONRY LEAF AND ATIMBER LEAF.• The ties are suitable for use in cavity walls with a masonry outer leafand a structural timber inner leaf and having a nominal cavity width of50 mm.• The ties are suitable for use in four-storey buildings up to 12 m high.

This Detail Sheet must be read in conjunction with the Front Sheets and DetailSheet 1, which give the products’ position regarding the Conditions ofCertification and Building Regulations, respectively.


DETAIL SHEET 6

Corus UK Limited(Catnic)

CATNIC TIMBER FRAME TIES TYPE BT2-4

Product

CI/SfB

(21.9) h3

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Design Data

3 General3.1 Catnic Timber Frame Ties Type BT2-4, whenused in accordance with this Detail Sheet, aresatisfactory for tying, over a nominal 50 mm cavity,a brickwork or blockwork outer leaf to the structuraltimber framework of domestic dwellings orindustrial/commercial buildings of up to 12 m andfour storeys.

3.2 The ties comply with the specification detailedin BS EN 845-1 : 2001

3.3 In addition to the requirements directly referredto in this Detail Sheet, timber frame buildings withan outer masonry leaf, into which the ties areincorporated, must be designed and/orconstructed in accordance with the appropriateStandards and Building Regulations:timber standards:

BS 5268-2 : 1996BS 5268-6.1 : 1996

masonry standards:

BS 5628-1 : 1992BS 5628-3 : 1985.

Building Regulations:

England and WalesApproved Document A1/2

ScotlandTechnical Standards, Part C, Small Buildings Guide

Northern IrelandTechnical Booklet D, Structure

4 Practicability of installation4.1 The ties can be built easily into a timber-framebuilding during construction.

4.2 As the timber studs are covered by sheathing,care is required to ensure that the ties are nailed tothe centre of the timber stud, eg marking the studline prior to fixing the ties.

4.3 Care needs to be taken when handling thesharp-edged ties.

5 Structural performance5.1 The declared load values of the tie inaccordance with BS EN 845-1 : 2001 andas tested to BS EN 846-6 : 2000 are given

in Table 1.

Table 1 Declared load values

Tensile load capacity 600 NCompressive load capacity 354 N

5.2 The tie density required to fix the outermasonry leaf to the timber frame is dependent onnumerous factors such as wind speed, groundtopography, ground roughness, building size andheight, and should be calculated by a suitablyqualified engineer using the declared load valuesshown in Table 1, together with appropriate safetyfactors and the procedures prescribed in BS 6399-2 :1997. As a guide, tie densities for use in urbanareas, in buildings up to 12 m and four storeys,calculated in accordance with CP 3 : Chapter V-2 :1972 [S2, category (3), Class A], are shown inTable 2. For use in other areas, the densities willalter.

Table 2 Tie densities for use in urban areas

Basic wind speed Tie density(1) Tie spacing (mm)(ms–1) (ties per m2) horizontal vertical

40 4.44 600 37544 5.56 600 30048 7.41 600 22552 7.41 600 225

(1) Tie densities calculated on the assumption that ties will be used along theline of structure at each floor level (see section 5.4).

5.3 In addition to the tensile and compressiveload characteristics detailed in section 5.1, the tieswill also accommodate other stresses likely to beencountered in timber-frame buildings such as thosebrought about by the differential vertical movementof the two leaves caused by the variation inmoisture content of the timber frame.

5.4 In buildings of three storeys or more where thecavity between the leaves of a panel wallcontinues past a floor, beam or column orintersecting wall which is assumed to act as asupporting structure for a panel, the designershould consider the need to install ties along theline of this structure to transfer to it the transverselateral load to be carried by the outer leaf.

6 Weathertightness

The ties are designed to prevent the passageof water to the inner leaf (see section 1.2)and with the timber frame sheathing suitably

protected (eg by vapour permeable membrane), inaccordance with good construction practice, thetimber frame and interior of the building, will beadequately protected from wind-driven rain.

7 Behaviour in relation to fire

7.1 The ties are non-combustible.

7.2 The fire resistance of timber-frame walls may becalculated by reference to BS 5268-4.2 : 1990 or,where necessary, by undertaking an appropriatetest at a United Kingdom Accreditation Service(UKAS) laboratory accredited for the test concerned.

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7.3 The timber framework must be lined to give thenecessary fire protection to the loadbearing studs.

Figure 2 Installation details

8 DurabilityWhen used in accordance with therequirements of this Certificate the ties shouldhave a service life of not less than 60 years.

Their durability will not be impaired by contact withconventional mortar admixtures or timberpreservative treatments.

Installation

9 Procedure9.1 Catnic Timber Frame Ties Type BT2-4 must bebuilt into the bed joints of masonry to a minimumembedment length of 55 mm. Care must be takento place them horizontally or with a slight fall to theouter leaf of the wall (see Figure 2).

9.2 The ties must be nailed through the sheathingto the centre of the timber stud, using the annularring-shanked austenitic stainless steel nails, suppliedby the manufacturer. The ties must be installed withthe lug uppermost.

9.3 The ties must be spaced to give the requiredtie density, determined in accordance withsection 5.2.



The following is a summary of the technicalinvestigations carried out on Catnic Timber FrameTies Type BT2-4.

10 TestsThe tensile and compressive strength characteristicsof the ties were determined in accordance withBS EN 846-6 : 2000 in both the horizontal, as-installed, position and also in a displaced position,simulating the downward vertical movement of thetimber frame by 24 mm, as may occur by thedrying-out of the timber frame over four floors.

11 Investigations11.1 The manufacturing processes wereexamined, including the methods adopted forquality control, and details were obtained of thequality and composition of the materials used.


water.


3

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Bibliography

BS 5268 Structural use of timberBS 5268-2 : 1996 Code of practice forpermissible stress design, materials andworkmanshipBS 5268-4 Fire resistance of timber structuresBS 5268-4.2 : 1990 Recommendations forcalculating fire resistance of timber stud walls andjoisted floor constructionsBS 5268-6 Code of practice for timber frame wallsBS 5268-6.1 : 1996 Dwellings not exceedingfour storeys

BS 5628 Code of practice for use of masonryBS 5628-1 : 1992 Structural use of unreinforcedmasonryBS 5628-3 : 1985 Materials and components,design and workmanship

BS 6399 Loading for buildingsBS 6399-2 : 1997 Code of practice for windloads

BS EN 845 Specification for ancillary componentsfor masonryBS EN 845-1 2001 Ties, tension strips, hangersand brackets

BS EN 846 Methods of test for ancillarycomponents for masonryBS EN 846-6 : 2000 Determination of tensile andcompressive load capacity and load displacementcharacteristics of wall ties (single end test)

BS EN 10088 Stainless steelsBS EN 10088-2 : 1995 Technical deliveryconditions for sheet/plate and strip for generalpurposes

CP 3 Code of basic data for the design of buildingsCP 3 : Chapter V LoadingCP 3 : Chapter V-2 : 1972 Wind loads


Date of issue: 11th March 2002 Chief Executive




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Documents

Electronic Copy - RIBA Product Selector · 2005-06-30 · In the opinion of the British Board of Agrément, Catnic Cavity Wall Ties and Insulation Retaining Clips are satisfactory