Low density, compressible, closed cell polyethylene filler for structural expansion joints and building facades

Product Applications

AEROFIL® 1 is a white, inert, preformed, closed cell, polyethylene joint filler suitable for structural movement joints in concrete, brick and blockwork.

AEROFIL 1’s low compressive strength prevents the transfer of load across joint interfaces and makes it ideal for forming soft compression joints and expansion joints in brickwork facades as recommended by BS 5628: Part 3: 1985 Use of Masonry Clause 20.4.

AEROFIL 1 is equally suitable as a low compression joint filler for bridge expansion joints as specified in Department of Transport, Scottish Development Dept., Welsh Office, Dept. of the Environment for Northern Ireland, Specification for Highway Works Series 1015 where it is essential to prevent transmission of horizontal forces to the abutment walls.

AEROFIL 1’s low density is also useful for forming isolation joints for machine bases or similar locations. The closed cell construction also prevents moisture absorption.

AEROFIL can be used on internal finishes as a gap filler or backing filler to walls, pipes, kitchen and sanitary ware before sealing with a surface sealant.


  • Low compression - accepts temperature cycles with minimal load transfer.
  • Closed cell - prevents water absorption.
  • Recovery - 90% after release of load.
  • Chemical resistant - inert to most dilute acids and alkalis, resistant to oil and hydrocarbons.
  • Easily worked - can be cut with sharp knife, economical in use.
  • Board form - for structural expansion joints in concrete, brick and blockwork.
  • Cut Strip form - in a range of sizes with rip-off edge to form neat sealant rebate.

Physical Properties

Property Typical Results Test Method
Density 28 Kg/m3 ± 10% ISO 845
Water absorption (after 7 days) vol. 1% ISO 2896
Chemical Resistance Inert to most dilute acids and alkalis, resistant to oil and hydrocarbons  
Compressive strength @ 50% strain 120 kN/m2 ± 30% ISO 3386-1
Operating Temperatures -5°C to +100°C Internal

All test results shown in this data sheet are determined under laboratory conditions and with the product sample taken directly from stock in its original packing without any alteration or modification of its component parts.

Product Installation

When used in board form for an expansion/movement joint, AEROFIL 1 shall be spot bonded in position using Pak Adhesive at approximately 10-12 sq m per litre to bond to the substrate after cutting to size with a Stanley knife or similar. (Full coverage 5 sq m per litre per face i.e. 2.5 m2 bonded area).

Specification Compliance

Department of Transport, Specification for Highway Works 1991 Clause 1015 (low compression for bridge expansion joints), Scottish Office Industry Department, Welsh Office, Department of the Environment for Northern Ireland, BS 5628: Part 3:2005 Use of masonry §5.4.3 Specification for Highway Works 2016 Clause 1015.

Details shown are typical illustrations only and not working drawings. For assistance with working drawings and additional technical advice please contact GCP Technical Services.


Aerofil 1 Boards 0.8 m x 2.0 m (1.6 m2)
Thickness 10 mm, 20 mm, 25 mm, 50 mm
Ancillary Products  
Pak Adhesive Pak Adhesive 5 litre can (Full coverage approx. 5 m2 per litre -2.5 m2 bonded area)
Complementary Materials VERTISEAL®, PARASEAL® & 2 part polysulphide sealants

NBS Specification Clause

Refer to Clause E40 520.

Health and Safety

There is no legal requirement for a Safety Data Sheet (SDS) for Aerofil 1. For health and safety questions on these products please contact GCP Applied Technologies Products Ltd

For Pak Adhesive and GCP Sealants read the product label and SDS’s before use. Users must comply with all risk and safety phrases. SDS’s can be obtained from GCP Applied Technologies or from our web site at | United Kingdom customer service: +44 (0) 1480 478421

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

AEROFIL is a trademark, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

© Copyright 2016 GCP Applied Technologies Inc. All rights reserved.

This document is only current as of the last updated date stated below and is valid only for use in the United Kingdom. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2022-11-24