Mansard Roof Insulation Details

Mansard roof with mansard tiles.

Mansard roof insulation details.

Does anyone have any advice on how to retrospectively insulate a mansard roof please. Ensure that a clear ventilation path is maintained from eaves to ridge where insulation is positioned between the rafters. There s a lot of heat loss from where the roof comes down the sides. Step 1 add a vapor barrier.

After having dense pack installed in the building walls the mansard is the next target. The steep roof with windows creates an additional floor of habitable space a garret and reduces the overall height of the roof for a given number of. Here s the house from the front. This barrier may not be fitted to an older home and you should consider getting a contractor.

One of the best ways to protect your mansard roof from the problems of ventilation is to use a vapor barrier on the inside. John in my opinion both slopes of a mansard roof the very steep lower roof and the shallow upper roof are roofs not walls. I have a house with mansard roof in boston. Lap the roof underlay over the mansard underlay by minmum 150mm.

If you insulate a roof with cellulose you either need a a ventilation channel between the top of the insulation layer and the underside of the roof sheathing or b an adequately thick layer of rigid foam on the exterior side of the sheathing hard to do with. A mansard or mansard roof also called a french roof or curb roof is a four sided gambrel style hip roof characterized by two slopes on each of its sides with the lower slope punctured by dormer windows at a steeper angle than the upper. I ve already lagged the loft but cannot get access to the cavity between the roof and upstairs walls from the loft. Originally i was toying with the idea of closed cell spray foam for the whole mansard floor but i do not want to tear down historic plaster.

Establish the correct number of courses of mansard tiles to maintain minimum headlap of 65mm.