The solution

Celotex tuff-R Zero CW3000 fulfils all of the requirements opposite

and is recommended for use in cavity wall applications.

CW3000 is supplied in a size designed to fit between wall

tie courses at 450 mm centres. Normally tuff-R boards should

be fitted against the inner leaf of the wall, but, where the

construction requires it, they may be fitted against the outer

leaf. (Other sizes may be supplied, subject to quantity).

The requirement

Specify a cavity wall insulation board that:

• achieves design U-values with minimum thickness

• has zero ozone depletion potential

• has low emissivity face for improved thermal resistance

to air spaces

• is strong and durable

• is non-hygroscopic

• is rot proof

• is dimensionally stable, unaffected by temperature cycles

• is easy to cut and shape

CI/SfB (21.9) Rn7 (M2)January 2003

Partial fill insulation of masonry cavity wallsCelotex tuff-R Zero CW3000

Celotex

Celotex tuff-R Zero CW3000 physical properties

Units Test method CW3000 Notes

Mechanical

Density (foam core) kg/m3 BS EN 1602 26–30 Varies according to thickness

Compressive strength kPa BS EN 826: 1996 >120 Design value

Water*

Water vapour resistivity MNs/gm BS 4370: Part 2 43373 As measured on 25 mm

board thickness

Heat

Thermal conductivity (λD) W/mK BS EN 12667:2001 0.023 declared value

harmonised standard

Service temperature °C Min. and max. –15 to

+100

Fire

Reaction to fire – BS EN 13823 Class D/s2/d0* Water vapour permeability value, as required by BS EN 13165 will be published on the Celotex website no later than 1st March 2003 (www.celotex.co.uk).

Product thickness table

Product code Thickness R-value Standard pack Standard pack

mm quantities (pieces) quantities (m2)

CW3020Z 20 0.85 25 13.50

CW3025Z 25 1.05 20 10.80

CW3030Z 30 1.30 16 8.64

CW3035Z 35 1.50 14 7.56

CW3040Z 40 1.70 12 6.48

CW3045Z 45 1.95 11 5.94

CW3050Z 50 2.15 10 5.40

CW3055Z 55 2.35 9 4.86

CW3060Z 60 2.60 8 4.32

CW3065Z 65 2.80 7 3.78

CW3070Z 70 3.00 7 3.78

CW3080Z 80 3.45 6 3.24

Board dimensions

CW3000 1200 × 450 mm

ASSESSMENT OF PRODUCTS FOR CONSTRUCTION

Certificate No. 94/3080

Celotex tuff-R Zero CW3000 product description

Celotex tuff-R Zero CW3000 is a rigid polyisocyanurate foam (Euro-

PIR) thermal insulation board, and is manufactured by continuous

autohesive lamination between aluminium foil facings. This third

generation board has zero Ozone Depletion Potential (ODP).

Benefits of all Celotex tuff-R CW3000 wall boards

• low thermal conductivity

• zero Ozone Depletion Potential

• resistant to high temperatures

• foil facings for low surface emissivity

• excellent dimensional stability

• robust and durable material

• non-hygroscopic

• easy to cut to shape

• conforms to BS EN 13165

• quality assured to BS EN 9002

• backed by the Celotex Technical Advisory Service, including

U-value calculation service

• Euro Class D reaction to fire (BS EN 13823)

• sized to fit between wall tie courses

• BBA certificate

BBA certification

Celotex tuff-R Zero CW3000 is approved for use in cavities up to

25 m in height. British Board of Agrément Certificate gives

details of compliance with the Building Regulations.

For walls exceeding 25 m in height, BBA offers an individual

assessment service, for which a nominal charge is made. For

further information, please contact either Celotex or the British

Board of Agrément.

U-values

In a typical cavity wall construction, comprising outer leaf of brickwork, inner leaf of 100 mm

blockwork and plaster internal finish, typical elemental U-values can be achieved by using the

following thicknesses of Celotex Tuff-R cavity wall insulation:

Required U-value0.35 0.3 0.27

Maximum block conductivity

CW3030Z 0.11 – –

CW3035Z 0.18 – –

CW3040Z 0.37 – –

CW3045Z Dense 0.17 –

CW3050Z Dense 0.30 0.12

CW3055Z Dense 0.95 0.29

CW3060Z Dense Dense 0.45

CW3065Z Dense Dense Dense

When you know the thermal conductivity of the block you are using, use the table above to identifywhich Celotex CW3000 thickness would be appropriate in the standard specification. Columnsshowing 'dense' indicate that the required U value can be achieved with all known block types.

Assumed specification for the above table

103 mm brick – cavity – CW3000 – 100 mm block – light plaster.

U-value calculation service

The thickness range of tuff-R CW3000 has been specifically engineered to achieve a variety of

mandatory U-values when used in conjunction with all major makes of concrete block.

Technical Services: T 01473 820888 F 01473 820889 E technical@celotex.co.uk W www.celotex.co.uk

Installation guidelines

• The wall ties used must be suitable for the structural

requirements and incorporate a cavity board retaining clip to

ensure that the insulation is held permanently in place.

• BBA approved wall ties and clips should be used wherever

possible. The advice of wall tie manufacturers should be

followed, but Celotex does not consider butterfly ties to be

suitable for use with partial fill cavity insulation.

• The first row of board retaining ties should commence at least

one course below the dpc, with the first row inserted at

maximum 600 mm centres horizontally, to provide a minimum

support of 2 ties per 1200mm board.

• To avoid potential damage to the dpc, wall ties should not be

inserted into a dpc course.

• The second and subsequent rows of ties should be installed at

vertical intervals of 450 mm and maximum 900 mm centres

horizontally. Where the cavity width is greater than 80 mm, or

where required for structural purposes, it may be necessary to

fit ties at increased frequencies.

• Always ensure that each full or cut board is retained by no less

than three ties around its perimeter.

• Fit the boards between the wall ties, and secure in place with a

retaining clip on each tie. Ensure that horizontal and vertical

joints are tightly butted to minimise heat loss.

• Where necessary, cut the boards to size, using a sharp knife

and straight edge.

• Where the cavity is closed at or below DPC level by a methane

barrier membrane, use mechanical fixings to secure the boards

to the blockwork above the DPC. Avoid puncturing the gas

barrier membrane.

Gable walls

At gable walls it is recommended that the insulation be taken

up to the underside of the roof verges. However, if a cold roof

construction is intended, the cavity insulation should extend at

least 250 mm above the ceiling. The top edge of the insulation

should be protected with a cavity tray.

Cavity barriers

Horizontal cavity barriers are not required at intermediate floors in

domestic buildings up to three storeys in height, but the cavity

must be closed at the top and around any openings. The Celotex

PIR foam, being a non-melting thermoset material, may pass

through cavity closers, so that a thermal bridge is avoided.

Cavity obstructions

Unavoidable projections within the cavity, such as floor edge

beams, need careful detailing and may require a horizontal

cavity tray.

Typical details

25mm

Internal angle

Detail at gable above ceiling

Suggested detail for steel columns

External angle

Cavity closure details

Technical Services: T 01473 820888 F 01473 820889 E technical@celotex.co.uk W www.celotex.co.uk

Celotex Limited

Lady Lane Industrial Estate Hadleigh Ipswich Suffolk IP7 6BA

T 01473 822093 F 01473 820880 E info@celotex.co.uk W www.celotex.co.uk

Storage and handling

• Celotex tuff-R CW polyisocyanurate foam boards should be

stored dry and kept flat and clear of the ground. Only as much

material as can be installed during a single working period

should be removed from storage at any one time. If boards are

stored under tarpaulins, care should be taken to prevent rope

damage to the boards.

• Care should also be taken to ensure that packs are not dropped

onto corners or edges.

• When cutting the product on site, use a trimming knife rather

than a saw, to minimise dust.

• When sawing in an enclosed space, dust extraction, eye

protection and face masks must be provided. Dust or

particles in the eyes should be washed out with liberal

quantities of water.

• Beware aluminium foil edges are sharp, avoid sliding bare

hands along board edges.

Health and safety

Full guidance on the appropriate measures to be taken by an

employer in accordance with the 1989 COSHH Regulations is

provided in Celotex Health and Safety Data Sheets

Quality and technology

Product and application development has a priority in Celotex,

with a focus on high performance, durability and buildability. The

Celotex commitment to the highest standards of quality assurance

includes stringent testing of product performance by our own

quality assurance staff and by leading independent authorities,

both in Britain and Europe. Full copies of certificates from the

British Board of Agrément are available on request.

Specification

Use ©NBS Plus specification writer clause F30.

Characteristics, properties orperformance of materials describedherein are derived from dataobtained under controlled testconditions. Celotex Limited makes nowarranty, express or implied as totheir characteristics under anyvariations from such conditions inactual constructions.

Typical details shown in thiscatalogue are provided for guidanceonly and are not to scale. CelotexLimited makes no warranty, expressor implied as to the suitability of suchdetails for any particular project. It isthe responsibility of the designer toensure that any design orconstruction details used aresuitable for the project, having dueregard to the environmental andstructural factors which are beyondthe control of Celotex Limited.

Not withstanding the foregoing,nothing herein stated shall excludeor restrict:

1 the liability of Celotex Limited inrespect of death or personal injurypursuant to the relevant provisions ofthe Unfair Contract Terms Act 1977, or

2 the liability of Celotex Limited inrespect of any damage caused by adefect to the extent that such comeswithin the relevant provisions of theConsumer Protection Act 1987.

Design principles

For most of the past century external masonry walls have been

predominantly of cavity construction. A cavity provides the most

effective barrier to rain penetration, and also adds to the thermal

resistance of the wall.

Modern energy conservation requirements demand added

thermal insulation in external walls, and the cavity offers the most

obvious location for the insulation. However, full cavity fill may

reintroduce the risk of moisture penetration, and many designers,

especially when considering exposed sites on hillsides or in

coastal regions, prefer to specify partial fill.

For partial fill design to achieve high standards of insulation

without a massive increase in the width of the cavity, and of the

overall wall thickness, then highly efficient insulation must be

used.

To comply with the requirements of NHBC, Zurich or HAPM, a

minimum 50 mm clear residual cavity should be provided in any

exposure zone.

For buildings up to 12 m high a minimum clear cavity width of 25

mm may be acceptable, subject to exposure. The 25 mm minimum

constructed residual cavity width must be clear of all obstructions.

Fire insurance

This Celotex tuff-R rigid Euro-PIR foam board is expanded using

hydrocarbon blowing agents.

Celotex also manufactures third generation ISO-PIR rigid foam

boards using non-flammable HydroFluoroCarbon blowing agents,

available under the Celotex double-R brand. Double-R is

specifically formulated to satisfy the very demanding

requirements of fire insurers for larger commercial & industrial

building applications. Although more expensive, because of the

blowing agent used, double-R may be the only option acceptable

to your client's fire insurer, by virtue of listing in the LPCB

approvals Guide.

Check with our Technical Advisory service for further information,

or refer to our ‘What's the flaming difference?’ Leaflet for a fuller

explanation of this issue.

B