Open cell and closed cell.
Under roof insulation spray foam.
1 some manufacturers advise that the spray foam is breathable some of them say nothing at all about this.
It has been in use for over 30 years and is now becoming increasingly popular as it s an effective insulator and can also stop air leakage.
2 many say it has a british board of agrement or bba approval which means the same thing.
Unvented roofs with spray foam applied to the underside of the roof deck have been used since the mid 1990s.
Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.
Lstiburek takes blame for bad language.
Technically known as spray polyurethane foam or spf spray foam is most commonly applied in the space between attic rafters.
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 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 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.
Serving as both an air sealant and an insulator spray foam is estimated to reduce the standard hvac sizing by about 35 on average.
Open cell spray polyurethane foam or closed cell spray polyurethane foam ccspf insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones see figure 1.
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.
Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.
According to the us environmental protection agency epa spray foam is recognized as a premier alternative to the batt insulation of years past.
This construction approach was first used in the 1970s and it has been implemented much more widely since it was first included in the international code council s icc model building code in 2007 irc section 806 4.
Open cell spray polyurethane foam ocspf and closed cell spray polyurethane foam ccspf insulation sprayed to the underside of roof sheathing is a popular strategy for increasing roof insulation levels in all climate zones.
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.
It can act as an air and moisture barrier in addition to providing very high r value.
It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.
There are two types of spray foam.