A ventilation chute between the foam and the wood deck that is connected from the soffits to the ridge vents is an option for some designs to ensure moisture if properly vented.
Spray foam insulation ridge vent.
Roof vents are great for allowing air to move and for removing toxic odours from the home.
Spray foam insulation is professionally installed at the same point in the construction cycle as other types of insulation.
Cathedral roofs especially need a lot more insulation between the ceiling and the rafters because there usually isn t any attic space.
Nothing unusual about that.
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.
That is using traditional building.
All insulation materials require proper venting.
Spray polyurethane foam is a chemical product that is created by two materials isocyanate and polyol resin that will react with each other when they are mixed and will expand up to 30 to 60 times its liquid volume as it is sprayed in place.
Unvented attic assemblies unvented attics rely on an air impermeable insulation installed to the roof deck s underside i e.
Rigid foam and spray foam are two of them.
Choose foam it green spray foam insulation kits and don t settle for less than you deserve.
Earlier this year i got a question about a home that had spray foam insulation in the attic.
Heat from the house rises up to the attic but when there isn t one the heat rises up to the roof.
The photo above shows the scar from a power attic ventilator installed in a spray foam attic but i ve heard of several cases where roofers installed or tried to ridge vents.
Spray foam kits are quicker and easier to use plus you get a seamless air barrier and high r value in just 1 inch.
Sealed attics should not have any type of attic ventilation connecting it to the outside.
The movement of air into indirect conditioning of an unvented attic is a slow gradual process that will not be noticeable by occupants and typically will not put any strain on the hvac system.
However many people think that roof vents cannot be used in conjunction with spray foam insulation.
This alternative to traditional building insulation fiberglass can be applied into wall cavities holes concrete slabs and even onto roof tiles and.
A lot of builders and homeowners are going with spray foam insulation because of the airtightness benefits but then the questioner mentioned that the spray foam contractor had intentionally left big holes to the outside by not sealing the gable vents.
