Floor Insulation

Floor insulation plays a critical role in reducing heat loss through ground floors, which can account for up to 15% of a building's total thermal loss. Whether you're constructing a new build, renovating an older property, or upgrading to meet Part L building regulations, properly insulated floors improve energy efficiency, reduce heating costs, and create a more comfortable living environment year-round.

Our Floor Insulation Product Range

McMahons stocks a comprehensive selection of underfloor rigid insulation boards from leading brands including Kingspan and Polyiso, suited to concrete floor construction and screed applications.

• Polyiso rigid boards - PIR insulation boards in a range of thicknesses (50mm, 80mm and more) delivering excellent thermal performance per millimetre, ideal for under-slab and screed applications where floor depth is limited.
• Kingspan Kooltherm K3 Floorboards - premium phenolic-core floorboards available in 25mm and 135mm thicknesses, achieving some of the highest thermal values available for floor applications and ideal for projects with tight floor-to-ceiling height constraints.
• Polyiso perimeter strips - insulating edge strips that line the perimeter of the floor slab to eliminate cold bridging at the wall-floor junction, an important detail for achieving full Part L compliance.

Browse our complete Insulation Materials range to find complementary products for your project, or explore our Air Tightness Insulation options to maximise energy performance in your build.

Selecting the right product depends on your floor construction type, required U-value, and available depth. Rigid boards are typically laid beneath a concrete slab or screed. Always incorporate perimeter insulation at the slab edge to prevent cold bridging at the wall base and ensure your floor assembly meets current building regulation requirements.

Why Choose McMahons for Your Insulation Needs?

With over 190 years serving Ireland's building trade, McMahons combines deep product knowledge with competitive pricing on leading insulation brands. Our staff understand building regulations and can help you specify the right materials for compliance and performance. Set up a McMahons trade account today for streamlined ordering, trade pricing, and efficient delivery to site.