Roof Insulation – Cathedral or Skillion Installation Guide

Cathedral Ceiling Insulation Supplier & Manufacturer

Simple step by step guide to installing Foilboard® Roof Insulation for Cathedral Ceiling Insulation or Skillion Insulation Installation.


Step 1

Foilboard® GREEN rigid insulation panel should be installed between the rafters where possible. Measure the width you require.

Step 2

Mark the measurements out on the Foilboard® GREEN rigid insulation panel using the gridlines as a guide. Using a straight edge and a sharp blade/knife, cut the rigid panel to size.

Step 3

Place the panel between the rafters and fix using the fasteners. Flexifast fasteners (inset) allow positioning anywhere on the rafter. Push the clip into the edge of the sheet before installing.

Step 4

Fasten the insulation panel between the rafters to the exposed battens using the Standard Timber of Steel Fasteners.

Step 5

Tape all joints and gaps using Foilboard® GREEN or silver joining tape, to minimise hot/cold air transfer.

Required to install

Use Foilboard® Standard Fasteners (timber frame) for Foilboard® GREEN 10 & GREEN 15 OR

Use Foilboard® Ultra Fasteners for Foilboard® GREEN 20 & GREEN 25

(Use Timber or Steel fasteners depending on application)

Flexifast Fastener

Foilboard® Flexifast Clip (fixing to side of rafter)

Use Foilboard® Green or Silver joining tape

Foilboard ® Tips

  • Install Foilboard® GREEN within the exposed rafters and plaster to finish
  • Ensure the Foilboard® GREEN is cut to a tight fit. Small gaps can be filled with silicone.
  • The Foilboard® GREEN antiglare is there to protect you. Both the antiglare and silver foil reflect heat.

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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