Tempo:
It is important to reiterate that the air barriers described for the following areas of a house must be connected and sealed in order to provide a continuous air barrier system.
Basement Floors A concrete floor or polyethylene sheet can serve an air barrier. The floor air barrier must be sealed to the air barrier in the below-grade walls. This can be done by caulking the joint between the floor and basement walls.
Walls Below Grade Concrete walls or polyethylene sheet can serve as an air barrier. The below-grade wall air barrier must be sealed to those of both the basement floor and the walls above grade; and should be caulked or sealed to the air barrier at the floor framing (for example, by wrapping the joist header with spun-bonded polyolefin as described in the next section) to make the air barrier continuous. If the basement walls are insulated on the interior, it is important to restrict the movement of air to the face of the concrete foundation wall because it will be cold, significantly increasing the potential for condensation. This can best be accomplished by placing rigid insulation directly onto the concrete and sealing insulation board joints.
(housewrap) from the inside of the lower wall, around the outside of the rim joist, to the inside of the wall above (Figure 7). The housewrap is then sealed to the polyethylene air barriers on the inside of the walls above and below. Because it is vapour-permeable, the housewrap will not impede vapour flow at the rim joist. Similarly, the junction between foundation walls and sill plates, the sill plate and joist headers and the rim joists and the subfloor material must be made airtight by installing sealants and gaskets between adjoining elements, or by wrapping the outside of the header with a sheet material capable of making the header airtight. 7
Carrying the air barrier around a rim joist at a floor intersection
sealant
Walls Above Grade When the air barrier is on the interior of the wall framing, it can be easily sealed to the polyethylene attached to the underside of the roof framing. However, it is difficult to install a polyethylene air barrier where the floor joists meet an exterior wall because the joists interrupt the continuity of the air barrier. It is good practice to wrap vapour-permeable (and air-impermeable) spun-bonded polyolefin
air tight rim wrap sealed to interior air barrier system
If the plane of airtightness is located on the interior of the building envelope, the electrical wiring, outlets and switches and recessed light fixtures penetrating through the plane
Basement Floors A concrete floor or polyethylene sheet can serve an air barrier. The floor air barrier must be sealed to the air barrier in the below-grade walls. This can be done by caulking the joint between the floor and basement walls.
Walls Below Grade Concrete walls or polyethylene sheet can serve as an air barrier. The below-grade wall air barrier must be sealed to those of both the basement floor and the walls above grade; and should be caulked or sealed to the air barrier at the floor framing (for example, by wrapping the joist header with spun-bonded polyolefin as described in the next section) to make the air barrier continuous. If the basement walls are insulated on the interior, it is important to restrict the movement of air to the face of the concrete foundation wall because it will be cold, significantly increasing the potential for condensation. This can best be accomplished by placing rigid insulation directly onto the concrete and sealing insulation board joints.
(housewrap) from the inside of the lower wall, around the outside of the rim joist, to the inside of the wall above (Figure 7). The housewrap is then sealed to the polyethylene air barriers on the inside of the walls above and below. Because it is vapour-permeable, the housewrap will not impede vapour flow at the rim joist. Similarly, the junction between foundation walls and sill plates, the sill plate and joist headers and the rim joists and the subfloor material must be made airtight by installing sealants and gaskets between adjoining elements, or by wrapping the outside of the header with a sheet material capable of making the header airtight. 7
Carrying the air barrier around a rim joist at a floor intersection
sealant
Walls Above Grade When the air barrier is on the interior of the wall framing, it can be easily sealed to the polyethylene attached to the underside of the roof framing. However, it is difficult to install a polyethylene air barrier where the floor joists meet an exterior wall because the joists interrupt the continuity of the air barrier. It is good practice to wrap vapour-permeable (and air-impermeable) spun-bonded polyolefin
air tight rim wrap sealed to interior air barrier system
If the plane of airtightness is located on the interior of the building envelope, the electrical wiring, outlets and switches and recessed light fixtures penetrating through the plane
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