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Insulate Lofts & Pitched Roofs

Therma-Foil insulation for use in Lofts and under Pitched Roofs

Performance Thermal Insulation in a Thin, Flexible, easy to install sheet

Therma-Foil works by reflecting infra-red radiation. This means that not only is our Foil Insulation effective in winter by reflecting heat back into the building and cold out, but also in summer. It is a very effective solar over heating barrier reducing the need for artificial cooling systems, preventing uncomfortable heat build up in the roof or penetrating into the rooms below.

How to install Foil Insulation In your Loft

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A staple gun and utility knife are the only tools required for installation.  In order to maintain maximum performance, Therma-Foil should be installed with a minimum of a ¾” airspace on one side.

When using Therma-Foil, lengths can be joined together using tape. To avoid gaps, the joins should be overlapped by 50mm-100mm before taping. We recommend that it should be stapled every 16” to 24”.


Leave 50mm clearance around heat producing flues or light fittings.

When installing ensure all exposed ends of the Foil Insulation can be folded to stop air ingress. Inspect finished work to insure it has been installed as air tight as possible. Install any additional insulation in accordance with the manufacturers’ guidelines. Always build in accordance with applicable Standards.


Roll out Foil Insulation on the roof (horizontally or vertically, we find vertically easier).  Fix to the rafters. If a roofing deck is being installed, allow the Therma-Foil to sag between the rafters. Fix to the sides of the rafters with staples. Rolls should be joined together as described above. The roof should then be battened and breathable membrane installed along with the roof cover, to requirements and applicable standards.

(To interior) Roll Therma-Foil out either parallel or perpendicular to the rafter and cut to required length. Finish right down to wall plate and fix in place.  Fix to rafters using staples and counter batten to prepare for finished ceiling. Using vapour controlled plaster board is recommended.  Therma-Foil can also be loosely fitted to allow it to be recessed back into rafter cavity.

Metal roofing: 

Roll Therma-Foil perpendicular to the purlins. Allow Foil Insulation to sag between the purlins. Join rolls of Therma-Foil together as described above. Fix roof sheeting through Therma-Foil as per requirements and applicable standards.


Therma-Foil in my loft  – it was very quick and easy to install – no need for gloves or protective clothing and the difference in warmth in the home in the winter months is considerable, providing me with huge energy saving!.  It also reduces heat-build-up in the summer, coming through the roof into the bedrooms below.   

Mrs C Wells (Poynton, Cheshire)


Browse Therma-Foil here.

Get your “FREE” sample pack of Therma-Foil here.

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