轻型木结构构造细节2

Possible Air Barrier Locations
Outside
Inside
Vapour Barrier
Must be located at the outside of the wall Interior finish vapour permeable to allow drying to inside
Foam Board Sheathing Air Barriers
Provides additional insulation value to the wall assembly Reduces thermal bridging through framing If the foam board has a low water vapour permeability without cavity insulation this wall assembly can be used safely in any climate in the world.
Inside
Vapour Barrier
Must be located on or towards the warm side of the insulation In most cold climates may be located partially inside wall with 2/3 of the insulation outside the vapour barrier In arctic regions 4/5’s of the insulation must be placed outside the vapour barrier.
Outside Vapour Barrier Location
Inside
Vapour Barrier
Must be located at the centre of the wall Interior and exterior finishes vapour permeable to allow drying to outside in winter and inside in summer
Cladding WRB Low perm foam board joints taped Sheathing
Insulation Interior Finish
Air Barrier and Vapour Barriers by Climate
Hot humid climates requiring cooling all year Air barrier location
Can be located anywhere in the assembly if vapour permeable If vapour impermeable must be located at the centre of the wall
Drainage / Ventilation Plane
Canada Wood Level 1 - Wood-Frame Construction
Construction Details Herbert Otto, B.Arch., MRAIC
Foam Board Sheathing Air Barriers
Extruded polystyrene or faced foam board insulated sheathings sealed at all joints and penetrations and sealed to ceiling and foundation air barriers Sealing options
Cladding WRB Sheathing Insulation Interior Finish
Air Barrier and Vapour Barriers by Climate
Mixed climates requiring heating in the winter and cooling in the summer Air barrier location
Foam Board Sheathing Air Barriers
Gasketed joint
Sill gasket stapled to wood framing at joint location Shiplap XPS nailed at joint into wood framing compressing gasket Gasket seals used at rough openings and window and door frames sealed with spray foam Foam board sealed to wall top and bottom plates for connection to foundation and ceiling air barrier
Vapour Barrier Location
Cladding WRB Sheathing Insulation Interior Finish
Air Barrier and Vapour Barriers by Climate
All climates Air barrier location
Can be located anywhere in the assembly if vapour permeable If vapour impermeable must be formed by the low permeance foam board insulation
Possible Air Barrier Locations
Outside Vapour Barrier Locations Inside
Vapour Barrier
Must be located at the centre of the wall. In this example the vapour barrier can be provided by a low permeance foam board insulation (XPS or foil faced urethane) or a waterproof WRB will act as the vapour barrier Interior and exterior finishes vapour permeable to allow drying to outside in winter and inside in summer
Cladding WRB Sheath Finish
Air Barrier and Vapour Barriers by Climate
Mixed climates requiring heating in the winter and cooling in the summer Air barrier location
Can be located anywhere in the assembly if vapour permeable If vapour impermeable must be located at the centre of the wall
Drainage / Ventilation Plane Possible Air Barrier Locations 1/2 1/2
Gaskets Urethane spray foam Compatible durable tape
Must tie into ceiling and foundation air barriers
Foam Board Sheathing Air Barrier Materials
Extruded polystyrene foam board Foil faced polyiso foam board insulation Foamed polyethylene sill gasket Aluminum foil tape with acrylic adhesive Contractor’s sheathing tape or peel and stick tape Nails with large plastic washers
Cladding WRB Low Perm Foam Board Joints Taped Sheathing Interior Finish
Capillary break
Rain Screen
Cladding spaced out from WRB typically by 12mm to 19mm (1/2” to ¾”) and larger in the case of brick veneer. Cross cavity flashings provided at all wall openings, penetrations and at floor lines. Provides capillary break between back of cladding and WRB Provides a drainage plane to redirect water back out of the wall that has penetrated the cladding. If vented top and bottom can enhance drying of the wall assembly In combination with WRB will resist reverse vapour drive.
Taped foam board sheathing air barrier
Air Barrier and Vapour Barriers by Climate
Climates requiring heating the majority of the year. Air barrier location
Can be located anywhere in the assembly if vapour permeable If vapour impermeable must be located on or towards the warm side of the insulation
Possible Air Barrier Locations Outside Possible Vapour Barrier Locations Drainage / Ventilation Plane 2/3 1/3
WRB shingled down face of sheathing overlapping flashings below
Cross cavity flashing
Floor line cross cavity flashing
Rain Screen Construction
Can be located anywhere in the assembly if vapour permeable If vapour impermeable must be located at the outside of the wall
Drainage / Ventilation Plane
Drainage / Ventilation Plane
Possible Air Barrier Locations
Outside Vapour Barrier Location
Inside
Vapour Barrier
Provided by low perm foam board insulation Interior finish vapour permeable to allow drying to inside