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Loft Insulation

Celotex loft insulation is an effective way to save energy and money at home without impacting on living space.

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The floor joists in roof spaces are not always suitable for bearing the loads of a habitable room, making a full conversion to new living space impossible. They remain useful areas for storage but laying timber boards directly onto flexible insulation causes it to compress and lose thermal performance.

Getting the best of both worlds means either installing non-structural joists across the existing ceiling joists to fit the insulation between, or buying a system of plastic pedestals to support the timber boarding.

Celotex’s rigid polyisocyanurate (PIR) foam insulation boards are a good solution, being able to accommodate storage loads without compressing. Timber boarding should be laid over them to protect the boards and maintain their performance, but some simple screw fixings are all that is required to secure the insulation in position.

The insulation is lightweight and does not impose significant weight on existing structural timbers. Rigid boards can be laid over the entire floor of the loft; or they can be used only in the area required for storage, with flexible insulation covering the rest of the floor.

What’s more, PIR insulation is efficient, requiring around half of the thickness of a typical flexible loft insulation product to achieve the same thermal performance. It can be used as part of a complete refurbishment of the loft floor, or in conjunction with existing insulation laid between the joists, to help reduce heat loss from the property and meet Building Regulation requirements where possible.

Advice should be sought with regard to correct installation practices, including ensuring a well-sealed ceiling below the loft joists, achieving continuity of insulation at the wall/roof junction without blocking eaves vents, and ensuring adequate ventilation of the loft space.


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Celotex products to consider

Celotex XR4000
1200 x 2400mm
0.022 W/mK

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Celotex GA4000
1200 x 2400mm
0.022 W/mK

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Celotex TB4000
1200 x 2400mm
0.022 W/mK

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