Underfloor Insulation (Flexifit) Installation Guide

Underfloor Insulation

Simple step by step guide to installing Foilboard® Green Rigid Underfloor Insulation (Flexifit)

Step 1

Measure the distance between joists (from inside edge to inside edge) and cut Foilboard® to suit the required width.

Step 2

Place Foilboard® Flexifast® clips at 600mm centres along the Foilboard® panels edge.

Step 3

Slide the Foilboard® GREEN rigid panel between the joist to the desired depth. (Foilboard® can be installed with either the silver face or green face exposed).

Step 4

Use a screw or nail to fix the Flexifast® clip to the sides of the joists.

Step 5

Use either Foilboard® Green tape or Silver tape to seal all butt joins between the panels and any other minor gaps.

Required to install

Flexifast Fastener

Foilboard® Flexifast clip

Flexifast Fastener

Foilboard® Green OR Silver insulation joining tape

Underfloor Insulation

Retractable Blade / Knife

Foilboard ® Tips

  • Imbedding the spikes of the Flexifast® clip into the FR-EPS core foam secures the panel in position, ensuring quick and easy installation of the panel
  • To minimise wastage, cut across the width of the panel (making each cut panel 1200mm long)
  • You can use a neutral cure silicon to seal any minor gaps
  • When marking out the panel, round up the measurement by 1- 2mm, this will ensure a snug fit and allow for any slight variation in the joists

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?