Flat Roof Dormer Insulation

We have a wide range of roof insulation products including flat roof insulation tapered insulation and pitched roof loft insulation.

Flat roof dormer insulation.

Tlx silver is a vapour barrier and this structure gives no risk of surface or interstitial condensation. The rigid insulation method requires the utilisation of 150mm thick insulation in between the rafters along with a 50mm air gap in order to avert cold bridging. Achieving a u value of 0 20w m meaning your roof will be better insulated than your walls will need 120mm thickness of rigid foam or 200mm of mineral wool or natural insulation. Tlx silver can be used to reduce the thickness of additional insulation required between the joists to help ensure a ventilated gap is maintained between the insulation and the deck.

Cold roof a very bad idea. When using the rigid form of insulation it is possible to place counter battens underneath the battens used for the tiles or slates. This is then covered with a further weatherproofing layer. Warm deck flat roof insulation is now the standard way to insulate a flat roof click to enlarge flat roofs for example on extensions bathrooms and dormer windows are not the best of ideas.

Since the dormer extends 2m outwards i can only imagine the insulation was either put there when the house was built or when if dormer roof was re roofed. Unfortunately too many dwellings suffer from this problem. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. To produce a hot roof rigid insulation is fitted outside above the weatherproofing.

The traditional cold deck flat roof system is to install the insulation between and under the joists with ventilation below the timber deck. Cold roof systems are highly inadvisable as insulation from the inside will inevitably lead to the formation of condensation. Insulating a dormer roof to insulate a new dormer the same three methods can be used however there are changes to the construction method that can be used. However after taking some photos on the flat roof it is apparent there is already some kind of insulation present.

Given below are 3 of the most popular methods by which you can insulate your dormer roof and the best way to tackle this task to achieve the desired results. The photos suggest 25mm of mineral fibre on the underside of the roof.