Insulation floor is a vital part of the home’s thermal envelope and can have significant energy savings. It also helps to mitigate moisture issues and improves living comfort, contributing to better air quality in the home.

The most common type of floor insulation is mineral wool or fiberglass batts or rolls, which are fitted between the joists. They are available in a range of R-values to suit different requirements. Other alternatives include cellulose or wood-fiber insulation, which are often used in crawl spaces and are suitable for concrete floors; or spray foam insulation which expands on application, filling gaps and cracks and providing an airtight seal.

Can I Use Loft Insulation Under Floorboards? Exploring Options

In newer buildings, it is typical for the floor to be insulated as part of the construction process. However, older homes often have solid concrete floors which are very difficult to thermally insulate. In such cases, a concrete slab method may be required, where insulation material is placed under the concrete, and in some instances rigid foam insulation boards are used.

Insulating a suspended timber floor can be more difficult as it involves lifting up the floorboards, which can be problematic and not always possible if the floor is valuable aesthetically or historically. However, there are companies like Q-Bot that use remote-controlled robots to spray insulation into the void under the floorboards, which allows the boards to remain in place and only requires minimal disruption. Other options for insulating a timber floor are a vapor barrier and tongue-and-groove wooden boards which can be fixed to the underside of the joists.