2lb spray foam underside roof deck.
Spray foam underside of roof deck.
2lb spray foam underside roof deck komfort insulation.
As air impermeable insulation spray foam insulation can be used in such applications.
Unvented roofs with spray foam applied to the underside of the roof deck have been used since the mid 1990s.
But spray foam insulation used at the underside of the roof deck would need to be covered by a thermal barrier and intumescent coatings are commonly used.
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.
It s not coming from above the roof and it s not some new moisture source resulting from the spray foam.