Cold Attic Insulation

Cold attic insulation is essential for reducing heat loss through your roof space, where up to 25% of a home's warmth can escape. By laying insulation between and over ceiling joists in unheated loft spaces, you create a thermal barrier that keeps living areas below comfortable while significantly cutting energy bills. This approach works best in attics used purely for storage rather than habitable rooms.

Our Cold Attic Insulation Range

We stock a comprehensive selection of loft insulation products from leading brands including Rockwool, Isover, and Moy, suited to Irish building regulations and climate conditions.

• Rockwool insulation rolls - stone wool rolls available in 100mm and 150mm thicknesses, non-combustible and easy to lay between joists, offering excellent thermal and acoustic performance.
• Isover acoustic rolls - glass wool rolls in 50mm and 100mm options, lightweight and easy to cut to size, ideal for achieving the required total depth across different joist heights.
• Isover Calibel insulated boards - insulated plasterboard for sloped or vertical attic surfaces, combining thermal performance with a finish-ready surface in a single product.
• Moy Metac rolls - a flexible mineral wool roll suitable for rafter-fit and between-joist applications where standard rolls may not fit neatly.
• Downlight covers - fire-rated covers for recessed light fittings that allow insulation to be laid over them safely without creating a fire risk.

For a complete thermal envelope, combine your loft insulation with proper Pipe Lagging & Jackets to protect water tanks and pipework from freezing in cold roof spaces.

When selecting insulation depth, aim for at least 270mm total thickness to meet current Building Regulations Part L requirements. If you already have 100mm between joists, adding a 170mm cross-layer on top eliminates thermal bridging through the timber and improves overall U-value performance.

Why Choose McMahons for Your Loft Insulation?

With nearly two centuries of experience serving Irish builders and homeowners, our team understands local building requirements and can advise on the most cost-effective solutions for your project. Browse our full range of Insulation Materials for walls, floors, and roofs. Ready to improve your home's energy efficiency? Check our delivery service to get materials delivered directly to your door.