How To Insulate A Pitched Roof Extension

For roof insulation on an extension or as part of your main home the spray foam is generally applied between the rafters of the roof which is ideal for pitched roof insulation.

How to insulate a pitched roof extension.

Stagger the horizontal joins. There will also be kooltherm k7 pitched roof board between the rafters image credit. But a pitched roof has more advantages than a flat roof. The only way to insulate it without removing the ceilings is if possible fit some rigid insulation board to slide down between the timbers.

The pitched roof helps to create an additional space at the home. A flat roof v s pitched roof extension is a topic to ponder as both roofs are in trend. The foam is sprayed between the rafters where it begins to expand at a rather rapid rate. A pitched roof is more durable and weather resistant.

If 180mm is to be installed then 100mm board might be introduced between the rafters there has to be a minimum 25mm air gap between the insulation and the underside of the tiles or slates with an 80mm board running across the rafters. When insulating a pitched roof with a sarking felt a minimum 50mm well ventilated cavity is required between the felt and the top of the insulation. Fitting the insulated plasterboard. You only have 5 inches and you need minimum 50mm air flow between board and tiles so you might get away with 75mm kingspan.

As this requires fitting insulation above the rafters the roof covering will have to be removed in order to fit the insulation. The bottom of the insulated plasterboard should meet the floor level of the roof space. This video shows you how to use knauf insulation glass mineral wool gmw with ecose technology applied between and below rafters. The flexibility of a pitched roof is unmatched with that of a flat roof.

To create a warm pitched roof insulation such as kingspan kooltherm k7 pitched roof board should be fitted between and over the rafters. In addition to this ventilated cavity a continuous vapour control layer should be positioned to the room side of all of the insulation. And made airtight using t. After cutting the plasterboard to width so that it fits between horizontal centres of rafters screw the insulated plasterboard to the rafters.

In a nutshell you would sandwich 130mm of solid insulation between two decks allowing to place a vapour barrier on top of the first deck.