Retrofit Underfloor Installation Guide

Simple step by step guide to installing Foilboard® GREEN rigid insulation


Step 1

Butt the Foilboard® against the bearer (below joists)

Step 2

Fix the sheet using the Foilboard® Fasteners to underside of joists in between bearers.

Step 3

Join sheets together and continue along underfloor cutting around any services as needed.

Step 4

Tape all joins to restrict any leakage.

Step 5

Seal the ends of the joists using strips of Foilboard® or similar to maintain still airspaces

Handling and Storage

Instructions are merely a guideline only and should be interpreted with consideration for the specific building application. All penetrations must be effectively sealed to reduce any risk of damage caused by exposure to extreme radiant heat. Alternative installation methods may be implemented. Safe installation practices are encouraged at all times. Please contact Foilboard Australia Pty Ltd for further information.

It is recommend that if the product is being stored for extended periods it should be kept clean and dry. Any moisture present between sheets should be dried to prevent potential oxidization and must not be stored with either foil surface in contact with any alkaline materials.

In need of further technical advice or assistance?

Foilboard® Technical Department is available to assist


Designing a Building?

Designing a Building?

Doing it yourself?

Doing it yourself?

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