INSULATION FOR NEW BUILDS AND EXTENSIONS

Extensions and new builds will have to be insulated to current Building control regulations. There are 2 common  ways to insulate a flat roof. 1st is a cold deck roof which is insulation between the joists with a ventilated air gap on top and nowadays a small layer underneath between joists and plasterboard.  2nd is to do as a warm deck roof which means a continuous layer of PIR insulation over a vapour control layer which sits on top of the timber roof deck. We personally feel that a warm deck roof is the most efficient way to insulate a flat roof. We can install with ply on top of the insulation or a fully bonded system in which we stick down TR27 insulation boards down and go straight over with our Alwitra system. This means no need for any plywood at the top of the build up and no need for any fixings which penetrate though the insulation. There is a diagram explaining the build up of a typical warm deck roof construction.

UPGRADING INSULATION ON EXISTING FLAT ROOFS

Most flat roofs built pre-1990 are seriously lacking in any insulation, which makes them terrible at keeping your heat in, costing you a fortune during the winter months.

Even though many actually have insulation between the joists, its usually a thin layer of fibreglass insulation and  the need for ventilation to prevent condensation forming and rotting the timber deck inside, means that this actually creates a very inefficient flat roof.

These are commonly known as cold deck roofs. Also, many of these cold deck roofs are not ventilated properly due to the lack of knowledge when built, and sometimes you could actually find that the roof space is sweating and condensation is the problem instead of a leak.

We can upgrade the insulation by either taking up the current roof and adding more insulation between the joists, making sure its vented properly or in most cases, the most efficient way is to install a warm deck roof on top of the decking. We always try to fill the void at the end of the joists too if installing a warm roof to avoid any cold bridging.

Be sure to get in touch for more information!