Typical Applications with a U-Value of 0.20W/m2K (Based on 600mm centres)

Below Rafter Installation & PUR / PIR Boards such as Celotex Tuff-R GA4075

 

Below Rafter Installation & PUR / PIR Boards such as Celotex GA4075 Tuff-R

 

.

Below Rafter Installation with 100mm Glasswool such as Knauf Rafter Roll 32

Above Rafter Installation with 100mm Glasswool such as Knauf Rafter Roll 32 100mm

Thermal performance

Calculations of the thermal transmittance (U value) of specific roof constructions incorporating the product should be carried out in accordance with BS EN ISO 6946 : 1997 and BRE report (BR 443 : 2006), Conventions for U-value calculations using the following values:

• Emissivity of outer layers 0.17

• Core thermal resistance 0.97

• Thermal resistance of insulation with minimum air layer either side 1.9

For constructions incorporating a number of non-ventilated cavities and a low overall U value, convective and radiative heat transfer across cavities can be less than those predicted by the ‘simplified’ method in BS EN ISO 6946 : 1997. This can be seen in the results of guarded hot box testing or by detailed calculations, for example using ISO 15099 : 2003. Such values are, however, construction specific and cannot be transferred between one construction to another.

Condensation risk

Interstitial condensation

Roofs incorporating the product will adequately limit the risk of interstitial condensation when designed and constructed in accordance with BS 5250 : 2002, Section 8.4 and Appendix D.

The risk of interstitial condensation is greatest when the building is drying out after construction. Guidance on preventing condensation from this and other sources is given in BRE Digest 369 Interstitial condensation and fabric degradation and BRE report (BR 262 : 2002) Thermal insulation: avoiding risks.

The product has a high water vapour resistance with a measured value in excess of 6000 MNsg–1.

When installed in accordance with section 13 and in a continuous layer, the product will provide a convection free envelope of high vapour resistance.

The product will perform as a vapour control layer and should be used in conjunction with a vapour permeable roof tile underlay.

In all cases, where high vapour resistance roof tile underlays are used, ventilation to the air space should be in accordance with the recommendations of BS 5250 : 2002 or relevant BBA Certificate for the roof tile underlay. When installed in conjunction with other insulation materials, the water vapour resistance and installation instructions of the additional insulation should be taken into consideration.

Surface condensation

Roofs will adequately limit the risk of surface condensation when the thermal transmittance (U value) does not exceed 0.35 Wm–2K–1 at any point and the junctions with walls are designed in accordance with the relevant requirements of TSO 2002 or BRE Information Paper IP 1/06.

Roofs will adequately limit the risk of surface condensation when the thermal transmittance (U value) does not exceed 1.2 Wm–2K–1 at any point. Guidance may be obtained from Section 8 of BS 5250 : 2002 and BRE report (BR 262 : 2002).

Behaviour in relation to fire

The Certificate holder has declared that the product when tested for reaction to fire to BS EN ISO 11925-2 : 2002, achieved a Class E rating in accordance with BS EN 13501-1 : 2007.

When installed with an internal lining board, eg 12.5 mm thick plasterboard, the insulation will be contained between the roof and internal lining board, until one is destroyed. Therefore, the insulation will not contribute to the development stages of a fire or present a smoke or toxic hazard.

The insulation must not be carried over junctions between roofs and walls required to provide a minimum period of fire resistance. The continuity of fire resistance must be maintained, for example as described in:

England and Wales — Approved Document B, Volume 1, Sections 5.11 to 5.12

Scotland — Mandatory Standard 2.2, clause 2.2.10(1) (1) Technical Handbook (Domestic).

Northern Ireland — Technical Booklet E, paragraph 3.21.

The use of the product will not affect the fire rating obtained by tiled or slated roofs when evaluated by assessment or test to BS 476-3 : 1958.

When installed with other additional insulation materials, the fire properties of these materials must be taken into consideration.

Proximity of flues and appliances

When the product is installed in close proximity to certain flue pipes and/or heat-producing appliances, for buildings subject to national Building Regulations the relevant provisions and guidance given below should be met:

England and Wales — Approved Document J

Scotland — Mandatory Standard 3.19, clause 3.19.4(1) (1) Technical Handbook (Domestic).

Northern Ireland — Technical Booklet L.

Air leakage

The insulation was tested to BS EN 12114 : 2000 with positive pressure of 50 Pa and 100 Pa. The leakage rate was 0.1 m3 h–1m–2 and 0.4 m3 h–1m–2 respectively.

When the product is used as a vapour control layer and an air barrier, the airtightness of the system is reliant on the careful sealing of the insulation and is dependent on maintaining the integrity of seal throughout. In addition to sealing at all joints, the insulation must be suitably sealed at the perimeter and all penetrations. Details of sealing at eaves, ridges, hips, valleys and penetrations must be in accordance with the Certificate holder’s instructions.

The airtightness of the building will also be dependent on the performance of the other building elements. Provided these also incorporate appropriate design details and building techniques, air infiltration through the building fabric should be minimal and the building reasonably airtight.

De-rating of electrical cables

As with other insulation products, it may be necessary in some cases to de-rate electrical cables buried in insulation. In BS 7671 : 2001 it is suggested that where wiring is completely surrounded by insulation, it may need to be de-rated to as low as half its free air current carrying capacity. Guidance should be sought from a qualified electrician.

Manufacturer

Euroform Products Ltd, The Heliport, Lyncastle Road, Appleton, Warrington WA4 4SN
Tel: +44 (0) 1925 860999 Fax: +44 (0) 1925 860066 Email: sales@euroform.co.uk

 

Page last updated Tuesday, June 1, 2010