Partial-Fill Cavity Wall Insulation

BEWI Partial-Fill Cavity Wall Insulation is manufactured from expanded polystyrene (EPS) and is designed to be incorporated into new masonry walls during construction.

The insulation is lightweight and easy to handle and is retained against the required leaf by clips on the wall ties.





         Key Benefits

  • Easy to install
  • Lightweight and easy to handle
  • Resistant to moisture
  • Durable and rot-proof
  • Maintains the cavity
  • A+ rating in the BRE Green Guide to Specification
  • Permanent insulation for the lifetime of the building

Product specification


Standard size: 1200 x 450mm.

Thickness: 25, 40, 50, 60, 75, 100 and 150mm.


BEWI Partial-Fill Cavity Wall insulation is supplied as EPS 70 (white) and EPS HP 70 (grey) as defined in BS EN 13163. Flame retardant additive material is available to order. Any necessary fire performance should be provided by the facing material and the system design.

Thermal Performance

A U-Value of 0.35W/m² K can typically be achieved with a 75mm thickness of BEWI Partial-Fill Cavity Wall Insulation based on a common cavity wall construction using a range of materials for both inner and outer leaf.

Downloads — Partial-Fill Cavity Wall Insulation

For more information please get in touch

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