Suspended Timber Floor Insulation Detail

At the turn of the 18th century when construction techniques moved from boarded floors installed directly on the ground to suspended timber floors over a ventilated chamber the innovation solved a significant problem.

Suspended timber floor insulation detail.

The building detail is for illustrative purposes only. Where insulation cannot be installed from below say above a jetty insulating above a suspended timber floor prevents damage to floorboards caused by lifting them. A disadvantage can be an unacceptable raising of the floor level necessitating step ups or alterations to details at door openings electrical sockets etc. Best practice for insulating a suspended timber floor part 2.

I can t get a definitive idea of the best way to do it. In this blog post we aim to provide a simple practical guide to the best practice methods for fitting insulation boards such as kingspan kooltherm k103 floorboard into a suspended timber floor. Suspended timber floors located above an unheated space where the insulation is installed below the floorboards or timber decking timber floors situated above an unheated integral garage. This is a floor where the timber floorboards are attached to floor joists and the insulation suspended on timber battens between the joists.

The answer to this problem can also be found in our project about stopping creaking floors and stairs. The floor would typically be finished from above with a vapour control layer vcl if required and a suitable timber floor deck. There are a variety of options for the material used in suspended timber floor insulation. Some support may be needed for the insulation timber straps timber battens or netting can all be utilised to help keep the insulation in place.

Materials for suspended timber floor insulation. I m 70 of the way through an eco retrofit of a 1940s bungalow windows already in place but still have about 30 m 2 of suspended timber floor to insulate and air seal. Suspended hollow or timber floors also have a tendency to creak as the nails work loose over time. Previously floor timbers had been prone to damp and rot thanks to their direct contact with the moist ground.