Flat Roof Dormer Insulation

Cold roof a very bad idea.

Flat roof dormer insulation.

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. With a flat roof this issue does not arise but the u value constraint and the amount of insulation needed is just the same. The photos suggest 25mm of mineral fibre on the underside of the roof. 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.

Cold roof systems are highly inadvisable as insulation from the inside will inevitably lead to the formation of condensation. We also have insulation boards suitable for more specialist roof applications for example inverted roof insulation and balcony insulation. 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. We have a wide range of roof insulation products including flat roof insulation tapered insulation and pitched roof loft insulation.

Now to the actual question how can you insulate a dormer roof. They lose loads of heat and are prone to leaking causing the materials to deteriorate. When using the rigid form of insulation it is possible to place counter battens underneath the battens used for the tiles or slates. To produce a hot roof rigid insulation is fitted outside above the weatherproofing.

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. 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. Unfortunately too many dwellings suffer from this problem. This is then covered with a further weatherproofing layer.

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. Tlx silver is a vapour barrier and this structure gives no risk of surface or interstitial condensation.