Expanded polystyrene (EPS) cavity closer, designed for closing cavities around openings in masonry, timber frame and steel frame wall constructions.

Features and benefits:

  • Available in two profile sizes to fit cavity widths between 50–150 mm.
  • Easy to install, with cut-to-size indicators included for guidance.
  • Fully ridged polyvinyl chloride (PVC) cavity closure.
  • Helps to prevent cold bridging.
  • Manufactured from recycled materials.
  • Reduces the risk of condensation, mould and moisture migration across the cavity.
  • Manufactured in accordance with BS EN 13163: 2012 +A1: 2015, and compliant with the relevant building regulations - consult manufacturer for further details.


Suitable for use in both new-build and refurbishment projects. Can be installed via the following methods:

  • Tack to window frame, built-in.
  • Built-in as work progresses (friction fitting).
  • Installed after the reveal has been constructed by fixing to the inner leaf, using grab adhesive.

See manufacturer's literature for detailed installation instructions.

Related literature

The following content references this product:

Standard product features


  • Outer casing: Extruded unplasticized polyvinyl chloride (PVC-U).
  • Insulation: Expanded polystyrene (EPS).




2.4 m.

Reaction to fire (to BS EN 13501-1: 2007 +A1: 2009):

Euroclass E.

Technical characteristics (to BS EN 13163: 2012 +A2: 2016):

  • Durability of reaction to fire against ageing/ degradation: Does not deteriorate with time.
  • Thermal conductivity: 0.030 W/m·K.
  • Thermal resistance: 25mm: 0.83 m²K/W.
  • Compressive stress at 10% deformation: 70 kPa.
  • Compressive creep: 0.3 σ 10.
  • Dimensional stability: At 23°C, 50% RH: 5; at 70°C, 90% RH: 1.
  • Bending strength: 115 kPa.
  • Shear strength: 180 kPa.
  • Shear modulus of elasticity: 1500 kPa.
  • Tensile strength: 140 kPa.
  • Water vapour diffusion resistance factor: 20–40 μ.
  • Water vapour permeability: 0.009–0.020 mg/(Pa.h.m).

NBS Specification

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This product is associated with the following NBS Create clause:
45-25-20/455 Plastics cavity closers

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Easy-Trim Roofing and Construction Products Ltd


+44 (0845 034 6008

Product reference

Cavity Closer


For cavity widths of 50–100 mm. 9 kg.
For cavity widths of 100–150 mm. 12 kg.

Manufacturer details

Unit 12b Metcalf Drive,
Altham Industrial Estate,
Lancashire, BB5 5JW
Tel +44 (0845 034 6008
Fax +44 (0)845 034 6010
NBS Plus
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