Carpentry
Skilled Trades 2201
Ceiling and Roof Framing
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The most commonly used types of residential
roof and ceiling construction are:
Joist and Rafter
Roof Truss
Ceiling and Roof Framing
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Ceiling Joists
Used to support the finished ceiling and in some cases
transfer roof loads to interior partitions. Ceiling joists
are generally 38 mm wide while their depth can vary
depending upon the species, grade, loading, depth of
span, and spacing between joists. This can be
determined by referring to the appropriate table in
“The Canadian Wood Frame House Construction
Handbook”.
NOTE: Ceiling joists rest directly upon the top plate.
Ceiling and Roof Framing
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Roof Trusses
Are presently replacing rafter and ceiling joist
applications in present day residential
construction. They require less material to
construct, can be erected more quickly, and do
not require interior bearing partitions. Basic
residential roof truss designs can be selected
from the appropriate table in “The Canadian
Wood Frame House Construction Handbook”.
Ceiling and Roof Framing
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Roof Rafters
Are used to transfer the loads supported by the
roof to the exterior walls or ceiling joists. These
rafters usually rest directly upon the wall plate.
Ceiling and Roof Framing
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Roof Rafters
Are used to transfer the loads supported by the roof to
the exterior walls or ceiling joists. These rafters usually
rest directly upon the wall plate.
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Roof rafters are also 38 mm wide while their depth can
vary depending upon the species, the grade, loading,
length of span and the spacing. This again can be
determined by referring to the appropriate table in
“Canadian Wood Frame House Handbook”
Ceiling and Roof Framing
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Roof Sheathing
Applied over the roof rafters or trusses
providing a nailing base for the roof covering.
Match lumber, plywood or particleboard may be
used for this purpose.
Framing Spacing
Minimum
Thickness
Lumber
400 mm
17 mm
Lumber
600 mm
19 mm
Plywood
400 mm
9.5 mm
Plywood
600 mm
9.5 mm
Particleboard
400 mm
9.5 mm
Particleboard
600 mm
11.1 mm
Type of Sheathing
Ceiling and Roof Framing
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Roof Coverings
Waterproof material which will provide
protection from the weather. The most popular
covering used on pitch roofs is asphalt shingles
although wooden shakes, tile, slate, copper and
aluminum sheet material are sometimes used.
For flat or low sloped roofs a combination of
pitch and gravel is used.
Ceiling and Roof Framing
Roof Cornice (Eave) Terms
 Eave: A projection of the roof out from the
exterior wall approximately 400 mm to 600
mm.
Ceiling and Roof Framing
Roof Cornice (Eave) Terms
 Eave: A projection of the roof out from the
exterior wall approximately 400 mm to 600
mm.
 Soffit: The underside of the eave projection. If
vinyl siding is used plastic soffit material can
be purchased to match the siding material
used
Ceiling and Roof Framing
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Fascia
Decorative Aluminum metal or straight edge
lumber attached to the ends of the roof rafters
to give a finished look to the roof assembly
Ceiling and Roof Framing
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Roof Vents
To provide ventilation of the attic, roof vents
are installed either in the gable ends or in the
soffit. These vents remove any moisture which
could condensate and cause rotting or insulation
damage.
Ceiling and Roof Framing
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Insulation
To prevent the loose of heat the building code
requires a min. Of R30 be used in the ceiling. In
addition a continuous vapour barrier of plastic
or some other waterproof material must also
installed under the ceiling sheathing materials to
prevent moisture from the interior of the house
from getting into the attic.