Tempo:
CHOOSING THE SIZE AND SPACING OF CEILING JOISTS Problem
Selection
Select the minimum ceiling joist that is acceptable for the following conditions:
Use Table 33 (p. 303).
Conditions
Attic is inaccessible and is not used for storage. Ceiling supports the insulation and drywall interior finish.
Span is 4.3 m (14 ft. 2 in.).
Ceiling joist spacing is 400 mm (16 in.).
Species group and grade specified is SPF No. 2 and better.
For this application select 38 × 140 mm (2 × 6 in.) ceiling joist. Note: In accordance with the National Building Code, the metric spacing of wood framing members is expressed as a “soft” conversions from the actual imperial dimensions. For example, spacing of 12, 16 and 24 inches on centre is converted to 300, 400 and 600 mm. on centre, respectively. In order to suit the imperial sizes of common 1 220 × 2 440 mm (4 × 8 ft.) panel products, such as gypsum board, OSB and plywood, the actual spacing of framing members is commonly adjusted to 305, 406 and 610 mm on centre, respectively.
94 Ceiling joists
span = 4.3 m (14 ft. 2 in.)
spacing = 400 mm (16 in.)
Selection
Select the minimum ceiling joist that is acceptable for the following conditions:
Use Table 33 (p. 303).
Conditions
Attic is inaccessible and is not used for storage. Ceiling supports the insulation and drywall interior finish.
Span is 4.3 m (14 ft. 2 in.).
Ceiling joist spacing is 400 mm (16 in.).
Species group and grade specified is SPF No. 2 and better.
For this application select 38 × 140 mm (2 × 6 in.) ceiling joist. Note: In accordance with the National Building Code, the metric spacing of wood framing members is expressed as a “soft” conversions from the actual imperial dimensions. For example, spacing of 12, 16 and 24 inches on centre is converted to 300, 400 and 600 mm. on centre, respectively. In order to suit the imperial sizes of common 1 220 × 2 440 mm (4 × 8 ft.) panel products, such as gypsum board, OSB and plywood, the actual spacing of framing members is commonly adjusted to 305, 406 and 610 mm on centre, respectively.
94 Ceiling joists
span = 4.3 m (14 ft. 2 in.)
spacing = 400 mm (16 in.)
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