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 the steep roof of a mansard.
Mansard roof insulation details.
I have a house with mansard roof in boston.
To insulate the roof you will need to use a combination of insulation to fully protect the roof.
One of the best ways to protect your mansard roof from the problems of ventilation is to use a vapor barrier on the inside.
After having dense pack installed in the building walls the mansard is the next target.
In my opinion both slopes of a mansard roof the very steep lower roof and the shallow upper roof are roofs not walls.
The ends may alternately attach to the base flashing where a change in roof slope occurs.
Due to its design in the extremely close to nature of this attic space a mansard roof format is a green roof design that is very well respected for its efficiency as well its use of space management.
Lap the roof underlay over the mansard underlay by minmum 150mm.
The name mansard actually means the attic or space inside the roof structure rather than just the shape of the roof.
So now i m thinking about just insulating the little attic which is formed by the low sloped part of the.
Mansard roof with mansard tiles ensure that a clear ventilation path is maintained from eaves to ridge where insulation is positioned between the rafters.
Mansard roofs are for the most part based on standing seam or batten seam construction.
The lower ends of the pans are typically hooked over an edge strip to form a drip.