Home > Companies > Geocel > AIRBLOCK Low Expansion Flexible Foam

Flexible foam which creates a highly effective air tight barrier to help air seal buildings. It fills voids and seals joints providing a huge improvement to energy efficiency. The unique formula gives low expansion during application, minimizing chances of distortion around frames and joints but with a flexibility that retains the airtight seal during natural expansion or contraction of the building materials.

Features/ Benefits:

  • One component, moisture curing, polyurethane foam that forms an airtight and water resistant flexible seal.
  • Fills voids and seals to improve energy efficiency.
  • Adheres to most common building materials including wood, concrete, brickwork, plaster, stone, plastic and metal surfaces.


  • Public buildings.
  • Sports stadia.
  • Hospitals.
  • Schools.
  • Hotels.
  • Factories and offices.
  • Railway and airport terminals.
  • Off shore structures.
  • Oil terminal Bund walls.
  • Oil terminal floor slabs.

Standard product features



Technical properties:

  • Application temperature: 5–30°C.
  • Service temperature: -40 to +100°C.
  • Tack free time: 10 minutes.
  • Apparent density: 27 kg/m³.
  • Air permeability: <0.1 m³/m.h.da.Pa.
  • Driving rain resistance: ≥600 Pa.
  • Reaction to fire (to DIN4102-1): Class B2.
  • Acoustic rating: 60 dB (to BS EN ISO 717-1).

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
45-55-75/370 Foam fillers

NBS Specification

NBS Buliding logo
This product is associated with the following NBS clauses:

Product specification

An important note about specifying





+44 (0)114 2409409

Product reference

AIRBLOCK Low Expansion Flexible Foam

Manufacturer details

Thorncliffe Park,
Sheffield, S35 2YP
Tel +44 (0)114 2409409
NBS Plus