Spray Foam Attic Rafters
Spray foam insulation that s convenient and easy to use.
Spray foam attic rafters. Encapsulating the rafter or top truss chord roof framing members with spray foam will improve the energy efficiency of the attic space. You don t need a lot just about an inch since the wood has some r value on its own. You don t want to pay to heat and cool more space than you have to. Nothing unusual about that.
The best attic insulation. This minimizes the potential for thermal bridging through the wood and provides better moisture condensation control. An attic that is properly vented has 50 intake of fresh air and 50 exhaust of the hot air. This is because the effects of thermal bridging are limited which also results in the elimination of melt lines on the roof surface in cold climates.
100 free of cfcs vocs penta bdes urea formaldehyde. The main concern with spray foam insulation and shingle warranty is proper attic ventilation. Class i e 84 fire retardant meets building code spec. If you do not have proper ventilation you are in essence cooking your shingles.
When you spray foam the rafters you are adding more space you pay to heat and cool. Insulate your attic floor unless you intend to use the attic for living space. Open cell spray polyurethane foam or closed cell spray polyurethane foam ccspf insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones see figure 1. Lstiburek takes blame for bad language.
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. 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. It s not coming from above the roof and it s not some new moisture source resulting from the spray foam. Get your kits the easy to use spray foam kit.
Use closed cell foam it green for attic rafters. Plus you re adding complexity to how you vent the attic to the outside. Unlike solid insulation products that require careful measurement cutting and fitting spray foam can cover even the most uneven surface instantly. 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.
Earlier this year i got a question about a home that had spray foam insulation in the attic.