To create an airtight seal use foil tape.
Installing styrofoam in attic.
Your board must leave at least inch gap between the board and the roof.
Work from the ridge toward the wall plates overlapping the.
Roof attic insulation of foam baffles ventilate insulate cold hot air youtube.
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.
Install the barrier by stretching it across the rafters from one end of the attic to the other and stapling it to the rafter faces.
When installing foam insulation boards in the attic make sure you start from one corner and work your way around the room.
Use furring strips nailed into the sides of the rafters so that you have something to fasten the board to.
Roof attic insulation of foam baffles ventilate insulate cold hot air.
You first install a very large amount of non permeable foam insulation it the rafters above your head in region 5 r 20 of insulation in order to prevent condensation seal it with spray foam and then attach an ignition barrier such as rock wool or drywall beneath the foam.
Nothing unusual about that.
Measure the length and width between two rafters in your attic and transfer the measurements to a 4 ft by 8 ft of rigid foam insulation board.
Install foam boards with the foil side facing you.
2 snap a chalk line between the length measurements.