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.
Spray foam roof deck.
Inspect the existing roof shingles or roofing membrane for any deficiencies.
Where wood shingles or shakes.
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Foam lok is spray applied to the roof s surface making it possible to vary the thickness of foam and ensure proper drainage.
Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.
Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.
Proper drainage prevents ponding water deck deflection and protects the roof from leaks and premature failures.
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.
This results in extended life span.
It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.
The installation steps are as follows.
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.
How spray foam should be installed on the underside of the roof decking the unvented attic space is completely within the building s thermal envelope.
The foam will also contract and expand depending on the weather which again reduces cracks.
As air impermeable insulation spray foam insulation can be used in such applications.
This measure will convert a vented attic to a nonvented attic.
Insulate an attic in an existing home by installing spray foam open cell or closed cell on the underside of the roof deck.
No interior class i vapor retarders e g plastic sheeting are installed on the ceiling side attic floor of the.
Applying closed cell spray insulation to the underside of a roof deck at the sheathing to truss connection can double or triple the strength of the assembly boosting the roof sheathing s resistance to wind uplift in a hurricane.