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.
Foam lok is spray applied to the roof s surface making it possible to vary the thickness of foam and ensure proper drainage.
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.
Where wood shingles or shakes.
Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.
Insulate an attic in an existing home by installing spray foam open cell or closed cell on the underside of the roof deck.
The foam will also contract and expand depending on the weather which again reduces cracks.
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Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly.
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.
Spray foam insulation applied on the underside of the roof deck in cold climate commercial buildings allows for a significant reduction in condensation potential particularly compared to interior air permeable batt systems.
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.
This measure will convert a vented attic to a nonvented attic.
With a spray on roof you can fill gaps seams and cracks in your existing roof construction giving you even more protection.
Proper drainage prevents ponding water deck deflection and protects the roof from leaks and premature failures.
The installation steps are as follows.
This results in extended life span.
No interior class i vapor retarders e g plastic sheeting are installed on the ceiling side attic floor of the.
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.
As air impermeable insulation spray foam insulation can be used in such applications.