EXTERNAL WALL INSULATION SYSTEMS / EPS /
TECHNICAL PERFORMANCE
ACCREDITATION & PERFORMANCE
The PermaRock EPS System has been assessed by BRE-Certifications (WIMLAS Certificate No. 029/95). Accreditation confirms the system’s suitability for use on masonry, dense and no-fines concrete, timber frame and metal frame walls. The system has an assessed lifetime in excess of thirty years.
AIR LEAKAGE
Buildings that are clad with the PermaRock EPS system exhibit minimal air leakage through the external walls. Performance standards for air leakage are set out in CIBSE TM23.
CONDENSATION CONTROL
PermaRock advises assessment of condensation risk in accordance with BS 5250. Full and comprehensive condensation risk and U-value analyses can be provided for specific wall constructions under any combination of environmental conditions and for any building usage.
DENSITY AND STRENGTH
PermaRock EPS Insulation Boards have an average density of approx. 15 kg/m3 and minimum compressive strength of 70 kPa.
DURABILITY
The assessed lifetime of the system is in excess of 30 years in accordance with BRE Certifications WIMLAS Certificate No. 029/95.
ENVIRONMENTAL
Buildings insulated with the PermaRock EPS System can achieve very low U-values resulting in considerable reductions in heat losses, savings in energy consumption and lower CO2 emissions.
PermaRock EPS Boards are CFC and HCFC free and do not employ ozone depleting chemicals in their manufacture - the system has zero ozone depletion potential (ODP). PermaRock EPS insulation has an embodied energy of approx. 92 MJ/m2 (60 mm thick).
FIRE PERFORMANCE
Expanded polystyrene is combustible when tested in accordance with BS 476 Part 4 or EN ISO 1182.
The PermaRock EPS System achieves a Class O rating with reference to the appropriate Building Regulations when tested in accordance with BS 476 Parts 6 and 7. For use on multi storey buildings, the system must incorporate fire barriers at intervals of no less than the line of every floor level above ground floor in the construction and where a compartment wall abuts, as recommended by and defined in BRE Defect Action Sheet 131.
IMPACT RESISTANCE
The PermaRock EPS system can withstand mechanical impact and abrasion without cracking or spalling. Resistance to soft and hard bodies complies with the recommendations of BRE publication BRE 6/81. Depending on specification, systems can achieve levels of impact resistance ranging from approx. 4J to in excess of 40J.
SERVICE TEMPERATURE
The PermaRock EPS System has high flexibility and can be designed to withstand the thermal shocks associated with climatic changes and will provide effective service at temperatures ranging from -20 ºC to +80 ºC.
The use of very dark coloured decorative finishes with the PermaRock EPS System is inadvisable - please consult PermaRock for further information.
WATER RESISTANCE
In-house testing and extensive assessment by BRE-Certifications confirms that the PermaRock EPS System withstands water penetration.
The system is classified as Type 4 insulating cladding for permeability to water, as defined in UEAtc MOAT No. 45.
The system is suitable for geographical areas including those classified as having very severe exposure to wind driven rain (BS 5628: Part 3 and BS 8104).
WATER VAPOUR PERMEABILITY
PermaRock EPS Insulation has a water vapour resistivity of 145 MNs/gm. The PermaRock EPS system with 50 mm insulation and dry dash aggregate finish has a measured vapour resistance (BS7374) of < 6 MNs/g.
WIND RESISTANCE
The system is designed to withstand high wind load and suction pressure. The values should be calculated in accordance with BS 6399: Part 2 (1997). In tests conducted at the BRE, PermaRock systems tested at a design load of -4 kPa showed no visible damage after being subject to wind suction loads representing 50 years exposure.
The system has also been successfully tested at loads of up to -9 kPa.