How to install 3 layers of SuperQuilt - Pitched Roof

This step by step guide will show you how to install three layers of SuperQuilt beneath the rafters of a pitched roof.

The SuperQuilt Triple Layer System is a space saving roof insulation solution designed to achieve a U-value of approximately 0.15 W/m²K without the need for rigid PIR insulation between the rafters.

The system uses one recessed layer and two continuous layers of SuperQuilt, with air cavities created between each layer. It can be installed with rafters from approximately 100mm deep, making it particularly useful where roof space is limited.

If your project is being submitted to Building Control, use our Online U-Value Calculator to confirm the required build-up and generate a project specific U-value calculation.

Before You Begin

Inspect the roof for any leaks, damp or damaged timbers before installing the insulation. Complete any necessary repairs first.

This installation method is based on insulating internally beneath a pitched roof with a suitable breather membrane already installed externally.

Measure and Cut the First Layer

Measure the roof and roll the SuperQuilt out horizontally across the rafters. Cut your first section to length using Multifoil Insulation Scissors.

Allow approximately 60mm of additional material for each rafter the insulation passes over. This provides enough material to recess the SuperQuilt between the rafters.

Recess the First Layer Between the Rafters

Position the first layer of SuperQuilt across the roof and recess it approximately 25 – 30mm between each rafter.

Staple the SuperQuilt to the sides and face of the rafters using 14mm staples, effectively weaving the insulation in and out while maintaining one continuous layer.

Tape and Seal the First Layer

Once the first layer is securely fixed, fully tape and seal all 50mm overlaps using ThermaSeal Foil Tape.

Seal around the perimeter and any adjoining timbers or junctions to create a continuous airtight layer.

Install the Second Layer of SuperQuilt

Install the second layer as a flat, taut and continuous layer directly beneath the rafters.

Secure the SuperQuilt through the first layer and into the rafters behind using suitable fixings.

Maintain a minimum 50mm overlap between adjoining sections.

Tape and Seal the Second Layer

Fully tape and seal all overlaps using ThermaSeal Foil Tape.

Seal around the complete perimeter of the insulation to maintain a continuous airtight and vapour control layer.

Install the First Set of Battens

Fix timber battens through the second layer of SuperQuilt and securely into the rafters behind. Install the battens at approximately 400mm centres.

Typically, 38mm or 50mm deep battens are used at this stage to create the required air cavity. Check your project specific U-Value Calculation to confirm the required batten depth.

Install the Third Layer of SuperQuilt

Install the third and final layer of SuperQuilt across the face of the battens.

Pull the insulation flat and taut before securing it using a Heavy Duty Staple Gun and 14mm staples. 

Continue across the complete roof area, maintaining a minimum 50mm overlap between adjoining sections.

Tape and Seal the Third Layer

Fully tape and seal all 50mm overlaps using ThermaSeal Foil Tape.

The perimeter of the SuperQuilt should also be completely sealed around walls, timbers and other junctions.

Install the Final Counter Battens

Fix minimum 25mm timber counter battens through the third layer of SuperQuilt and into the battens or rafters behind.

Install the battens at approximately 400mm centres, providing a fixing point for your internal finish while maintaining the required air cavity beside the SuperQuilt.

Finish with Plasterboard

Fix 12.5mm plasterboard directly to the final counter battens.

The plasterboard can then be jointed or skimmed to create your finished internal roof surface.

The exact U-value achieved will depend on your roof construction and batten depths. Use our Online U-Value Calculator to confirm the expected thermal performance and generate a calculation for Building Control.

Disclaimer – Ecohome Insulation cannot be held responsible for any losses financially or physically from advice provided in this How-To-Guide.