Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.
Spray insulation on underside of roof.
Polyurethane or polystyrene spray foams can provide thorough coverage to roof rafters and attic walls in much less time than is needed for other materials.
The roofing materials are installed and consist of timberline shingles and full coverage ice and water barrier the entire roof.
But that only works if the installer can get it into the places where most of the air leakage happens.
Spray foam insulation is an incomplete name.
In most cases the recommendations are based on mineral wool insulation to a depth of 270mm on the floor of the loft.
It really should be called spray foam insulation and air barrier.
Moisture generated indoors or that infiltrates into the home is responsible for the bulk of the moisture in an attic insulated with spray foam on the underside of the roof sheathing.
A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home.
1 some manufacturers advise that the spray foam is breathable some of them say nothing at all about this.
The attic will be a conditioned space and i m planning to apply spray foam insulation to the underside of the roof sheathing.
2 many say it has a british board of agrement or bba approval which means the same thing.
Lstiburek takes blame for bad language.
It will help you to eliminate problems that may come when the house becomes extremely cold in the winter and terribly hot in the summer.
Polyurethane spray foam metal roof insulation in order to add moisture barrier under metal roof you can spray the undersides of the roof by using a thick layer of polyurethane spray foam.
Watch this video on youtube.
The spray on foam is a rigid foam that is lightweight normally sprayed on to the underside of the roof approximately 50 to 100 mm thickness.
It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.
Yes you can spray foam the underside of your roof.
Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.
You can spray foam anywhere you d like to separate the inside from the outside.