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 insulation roof deck.
This measure will convert a vented attic to a nonvented attic.
Lstiburek takes blame for bad language.
The later is used in new construction as the interior board serves as an inner wall.
It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.
Insulate an attic in an existing home by installing spray foam open cell or closed cell on the underside of the roof deck.
Most unvented attics incorporate spray polyurethane foam spf on the underside of the roof deck and attic walls.
This retrofit assembly is appropriate for homes with conditioned attics or where the retrofit is intended to create a conditioned attic.
The last requirement is the installation of your shingles must be performed in strict accordance with the owens corning installation instructions.
You may have odor problems.
The spray foam can also serve as the thermal and vapor control layers in both new and retrofit construction.
It typically has 3 variations.
Air permeable insulation applied to the under side of minimum r 10 air impermeable insula tion spray foam or rigid board which is applied directly to the underside of the roof deck.
As air impermeable insulation spray foam insulation can be used in such applications.
Install insulating sheathing above the roof deck on existing homes.
Rigid foam board is just above the roof deck or an exterior insulation option.
When the choice is made to insulate along the underside of the roof deck spray foams have advantages over other insulation types because of the ability of spray foams to effectively air seal complex assemblies.
All spray foam insulation radiant barrier and other components of the roof deck must be installed in accordance with manufacturer s installation instructions.
Remove existing roofing and non adhered underlayment to expose roof sheathing.
Your indoor air quality may get worse.
By encapsulating the attic and leaving the old insulation up there that filth is in your conditioned space.
The installation steps are as follows.
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.
Inspect the existing roof shingles or roofing membrane for any deficiencies.
Yeah you probably still breathed some of it but not as much as you will now with spray foam on the roof deck.