Robust Detail

Description ISOVER RD35 is a specially engineered high performance acoustic slab, installed between wall ties in a masonry wall cavity. The foil-faced product is supplied in a 1200mm x 455mm dimension, compatible with conventional wall tie spacing. ISOVER RD35 has been developed as an acoustic insulant in masonry party walls and, following extensive site testing, has been approved as Robust Detail E-WM-8 by the RD Assessment and Approval Committee. Party walls constructed to E-WM-8 incorporating ISOVER RD35 will meet the performance requirements of Part E without the need for pre-completion site sound tests whilst removing the need for a wet-applied parge coat. A normal internal lining of plasterboard on dabs, fixed directly to the bare block face is all that is required, offering significant cost savings.

Ecological Information ISOVER RD35 is made from glass mineral wool, one of the most environmentally friendly materials available. Sustainable ISOVER RD35 is manufactured from silica sand, the earth's most abundantly occurring mineral and a sustainable, infinite resource. Recyclable Approximately 80% of the raw material used in the production of ISOVER RD35 is recycled,far more than any comparable product. The recycled material can be post-consumer glass (from housing generation projects) or waste glass from bottle and flat glass manufacture, which would otherwise go to landfill. Environmental The manufacturing process does not use or contain CFC's, HCFC's or other damaging gases - nor has it ever. In addition, the unique resilience of ISOVER glass mineral wool enables high compression packing which means more insulation in a smaller space than almost any other insulant. The result is better vehicle utilisation, reducing the environmental impact of transportation.

EcoHomes/Sustainable Homes ISOVER RD35 achieves full credit under BRE EcoHomes performance for zero Ozone Depletion Potential (ODP) and a Global Warming Potential (GWP) of less than 5. Credit will also be issued with ISOVER RD35 under pre-completion sound testing, delivering + 5dB above minimum Part E requirements. Standards Building Regulations England and Wales The use of ISOVER RD35 in E-WM-8 in houses and apartments will allow compliance with the performance requirements of Part E without the need for pre-completion sound testing. Building Regulations Scotland The Robust Detail scheme is referred to in the Scottish Building Standards: Technical Handbook: Section 5: Noise (formerly Part H) and is currently undergoing a full review with the intention of incorporating as an alternative method of compliance.

Quality Assurance Standard ISOVER RD35 is manufactured under a BSI Quality Assurance Scheme in accordance with BS EN ISO 9002: 1994.

Benefits of using RD35

Part E - Robust Detail E-WM-8 approval.

No need to use wet trades - no parge coating is required.

Avoids the need for pre-completion testing - no site sound test required.

Significant cost saving compared to -parge coat - Robust Details.

Totally non-combustible - A1 Euroclass rating.

Sustainable - made from sand, an infinite natural resource.

Environmental - up to 80% recycled waste glass goes into the production process.

Product Performance

ISOVER RD35 is a unique and fundamental component of Robust Detail E-WM-8 party wall construction. This construction system has been proven by an intensive programme of in-situ site testing in accordance with the protocol laid down by Robust Details Limited.

The table opposite shows performance figures obtained from at least 30 field tests on separating walls incorporating ISOVER RD35. Note: For airborne performance, the higher the value, the better the sound insulation.

Construction Characteristics

Robust Detail E-WM-8 construction is based on 2 leaves of lightweight aggregate blocks (minimum cavity width 75mm leaf to leaf), with a gypsum-based 'dot-and-dab' applied board finish. A render or parge coat is not required. The nominal specified weight of the gypsum-based board is 9.8kg/m2 and the board thickness can be 12.5mm or 15mm provided that the nominal weight requirement is achieved.

ISOVER RD35 slabs are installed as a partial-fill, positioned in the party wall cavity between wall ties and held in place with retaining discs in the normal manner as for installing insulation slabs in external walls. The ISOVER RD35 slabs must be installed with the foil-facing the residual 40mm (minimum) cavity. The acoustic slabs must be tightly butted together, and half cuts made with a clean sharp knife. Unless the external (flanking) wall cavity is fully filled with Hi-Cav (see diagram A), the junction of party wall cavity/external wall cavity must be closed with an ISOVER Cavity Barrier to prevent flanking noise transmission (see diagram B). It is a good design detail to continue the installation of the ISOVER RD35 slabs to the full height of the separating wall up to the underside of the roof.

Typical Cavity T-junction details to prevent flanking noise transmission

Packaging and Physical Dimensions
ISOVER RD35 is manufactured in slab form in a single thickness. The slabs are compression packed in individual packs using a strong polythene packaging film. The packs are then stacked on wooden pallets with final weatherproof outer covering, giving the option of outside storage.