Loft Insulation

Loft insulation is a thermal barrier installed in the roof space of a building to reduce heat loss through the ceiling. An uninsulated loft can account for around a quarter of a home's total heat loss, making it one of the most impactful areas to address when improving a property's energy performance. Installed correctly, loft insulation reduces heating costs, helps maintain a stable indoor temperature year-round and can contribute positively to a property's EPC rating.

The right type of loft insulation depends on how the space is used. In a cold loft, where the roof space is unoccupied, insulation is laid at ceiling joist level. The current recommended depth for mineral wool is 270mm, typically achieved in two layers: 100mm between the joists, with a further 170mm across the top at right angles. Many older properties can be topped up to this depth without any structural work, though care should be taken not to push insulation into the eaves, as this restricts airflow and can lead to condensation in the roof space. In a warm loft or loft conversion, insulation is fitted between and under the rafters instead, with the required thickness determined by rafter depth and the target U-value for the build.

Types of Loft Insulation

Loft Roll Insulation

Mineral wool roll is the standard choice for insulating at joist level in a cold loft, available in a range of thicknesses from 100mm to 200mm from Knauf, Superglass and Isover.

Between Rafter Insulation

Mineral wool slabs, phenolic boards and PIR strips for loft conversions and warm roof applications where insulation sits within the roof structure rather than at floor level.

Sustainable Insulation

Natural fibre alternatives to conventional mineral wool, including CosyWool from the Thermafleece range, made from 75% British sheep's wool, and SupaSoft, made from recycled plastic bottles.

Acoustic Insulation

Roll and slab format insulation for loft conversions and habitable roof spaces where both thermal and sound reduction performance are required.

Fire Resistant Insulation

Insulation for loft and conversion applications where fire performance is a specification requirement.

Why Choose Insulation UK for Loft Insulation?

A Comprehensive Loft Insulation Range in Stock covering mineral wool rolls, between rafter slabs, sustainable, acoustic and fire resistant options

Leading Manufacturers including Knauf, Superglass, Rockwool, Isover, Thermafleece and Tekwarm.

Fast UK-Wide Delivery with free shipping on orders over £500 ex VAT and next day options available on selected lines.

Expert Help and Advice from a team with over 50 years in the industry, on hand to help with product selection, thickness specification and material choice across any loft application.