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External wall insulation

Saint-Gobain Isover supply innovative insulation solutions to the UK construction industry.  Its high performance glass mineral wool insulation provides thermal efficiency, acoustic comfort and fire protection.

Saint-Gobain Isover can provide a number of products for masonry, timber frame and steel frame external walls.



Isover Cavity Wall Slab and Isover Hi-Cav 32 - glass mineral wool full-fill cavity slabs providing excellent thermal performance in masonry cavity walls to meet or exceed the requirements of Approved Document L (England and Wales).

  • No requirement for retaining discs on wall ties - Isover full fill insulation negates the need for retaining discs saving on material costs and installation time
  • No requirement for cavity fire barriers - Isover full fill insulation helps minimise flanking sound transmission and prevents the spread of fire within the external wall cavity
  • Reduced air gaps at joints - Isover full fill insulation has flexible properties allowing the slabs to fit together with minimal air gaps and heat loss


Timber Frame


  • Isover Timber Frame Batt - a glass mineral wool batt providing thermal and acoustic insulation for timber walls to help meet Approved Document L (England and Wales) and Section 6 (Scotland).
  • Isover Timber Frame Roll - a glass mineral wool roll providing thermal and acoustic insulation for timber walls to help meet Approved Document L (England and Wales) and Section 6 (Scotland).
  • Isover Frame Façade Slab - a low lambda rigid glass mineral wool slab providing a continuous layer of insulation around timber frame constructions. The product has a weatherproof breathable facing to protect the construction and negate the need for an additional breather membrane. Full range of accessories available including wall-ties, spacers and sealing tape.


Steel Frame

Isover steel frame insulation system - SF3+ is a three part insulation system for use in lightweight steel frame walls in new-build projects that combines the benefits of Isover Steel Frame Batts, Isover Steel Frame Infill Batts and Isover Self Adhesive Cavity Barriers. In addition, it offers the further option of the Isover Vario Membrane to improve air leakage performance and airtightness through its patented technology.

Moisture management


Vario KM Duplex is the next generation vapour control membrane for use in existing and new build roof and wall constructions, with the added benefit of bringing excellent air leakage performance to the building envelope.

It consists of an innovative nylon based membrane, which provides more flexible vapour control than low permeability polythene films which can trap moisture in the assembly during certain seasonal conditions. By absorbing water from the air and thereby opening molecular pores, Vario changes its vapour permeability with the ambient humidity conditions.

Vario film has a thickness of 50μm, combined with low flammability.

Companies specialising in External wall insulation

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