1) Subject to the application limitations defined
elsewhere in this Part, structural members and their
connections shall
a)conform to requirements provided elsewhere in this Part,
b)be designed according to good engineering practice such as that provided in the “Engineering Guide for Wood Frame Construction,” published by the Canadian Wood Council, or
c)be designed according to Part 4 using the loads and deflection and vibration limits specified in
i)Part 9, or
ii)Part 4.
2) Where floor framing is designed in accordance with
Clause (1)(b) or (c), and where supporting wall framing and fastenings, or footings,
are designed according to Clause (1)(a), the specified live load on the floor shall not exceed 2.4 kPa.
3) Location-specific information for structural
design, including snow and wind loads and seismic spectral
response accelerations, shall be determined according to
Subsection 1.1.3. (See Appendix A.)
1) This Subsection applies to light-frame constructions
whose wall, floor and roof planes are generally comprised of
frames of small repetitive structural members, and where
a)the roof and wall planes are clad, sheathed or braced on at least one side,
b)the small repetitive structural members are spaced not more than 600 mm o.c.,
c)the clear span of any structural member does not exceed 12.2 m,
d)the maximum deflection of the structural roof members conforms to Article 9.4.3.1.,
e)the maximum total roof area, notwithstanding any separation of adjoining buildings by firewalls, is 4 550 m2, and
f)for flat roofs, there are no significant obstructions on the roof, such as parapet walls, spaced closer than the distance calculated by
where
| Do | = minimum distance between obstructions, m, |
| Ho | = height of the obstruction above the roof, m, |
| Ss | = ground snow load, kPa, and |
| γ | = unit weight of snow, kN/m3. |
1) Except as provided in Sentences (2) and (3), specified snow loads shall be not less than those calculated using the
following formula:
where
| S | = specified snow load, |
| Cb | = basic snow load roof factor, which is 0.45 where the entire width of the roof does not exceed 4.3 m and 0.55 for all other roofs, |
| Ss | = 1-in-50-year ground snow load in kPa, determined according to Subsection 1.1.3., and |
| Sr | = associated 1-in-50-year rain load in kPa, determined according to Subsection 1.1.3. |
2) In no case shall the specified snow load be less than
1 kPa.
3) Bow string, arch or semi-circular roof trusses having
an unsupported span greater than 6 m shall be designed in
conformance with the snow load requirements in
Subsection 4.1.6.
1 ) Balconies, decks and other accessible exterior
platforms intended for an occupancy and subject to snow loads shall be designed to carry the specified roof snow load or 1.9
kPa, whichever is greater, where the platform, or each
segregated area of the platform, serves a single dwelling unit. (See Appendix A.)
1) The ceiling joists or truss bottom chords in residential
attic or roof spaces having limited accessibility that
precludes the storage of equipment or material shall be designed
for a total specified load of not less than 0.35 kPa, where the
total specified load is the sum of the specified dead load plus the specified live load of the ceiling. (See Appendix A.)
1) The maximum deflection of structural members shall
conform to Table 9.4.3.1.
2) Dead loads need not be considered in computing deflections referred to in
Sentence (1).
| Table 9.4.3.1. Maximum Deflections Forming Part of Sentence 9.4.3.1.(1) |
||
| Structural Members | Type of Ceiling Supported | Max. Allowable Deflection as an Expressed Ratio of the Clear Span |
|---|---|---|
| Roof rafters, roof joists and roof beams | No ceiling | 1/180 |
| Other than plaster or gypsum board | 1/240 | |
| Plaster or gypsum board | 1/360 | |
| Ceiling joists | Other than plaster or gypsum board | 1/240 |
| Plaster or gypsum board | 1/360 | |
| Floor beams, floor joists and floor decking | All cases | 1/360 |
| Beams, joists and decking for balconies, decks and other accessible exterior platforms | Serving a single dwelling unit | 1/240 |
| Other | 1/360 | |
1) Footing sizes for shallow foundations shall be
a)determined in accordance with Section 9.15., or
b)designed in accordance with Section 4.2. using
i)the maximum allowable bearing pressures in Table 9.4.4.1., or
ii)allowable bearing pressures determined from subsurface investigation.
| Table 9.4.4.1. Allowable Bearing Pressure for Soil or Rock Forming Part of Sentence 9.4.4.1.(1) |
|
| Type and Condition of Soil or Rock | Maximum Allowable
Bearing Pressure, kPa |
|---|---|
| Dense or compact sand or gravel(1) | 150 |
| Loose sand or gravel(1) | 50 |
| Dense or compact silt(1) | 100 |
| Stiff clay(1) | 150 |
| Firm clay(1) | 75 |
| Soft clay(1) | 40 |
| Till | 200 |
| Clay shale | 300 |
| Sound rock | 500 |
| Notes to Table 9.4.4.1. | |
|
|
|
| (1) | See Appendix A. |
1) Where a soil or rock within a distance equal to twice the footing width below the bearing surface has a lower allowable bearing pressure than that at the bearing surface as shown in Article 9.4.4.1., the design capacity of the foundation shall not be greater than would cause the weakest soil or rock to be stressed beyond its allowable bearing pressure.
2) In calculating subsurface pressures referred to in
Sentence (1), the loads from the footings shall be assumed to be
distributed uniformly over a horizontal plane within a frustum
extending downward from the footing at an angle of 60°
to the horizontal.
1) Where a foundation bears on gravel, sand or silt, and the water table is within a distance below the bearing surface equal to the width of the foundation, the allowable bearing pressure shall be 50% of that determined in Article 9.4.4.1.
1) Where a foundation is located in an area where soil movement caused by changes in soil moisture content, freezing, or chemical-microbiological
oxidation is known to occur to the extent that it will
damage a building, measures shall be taken to preclude such movement or to
reduce its effects on the building so that the building's stability and the performance of assemblies will not be adversely
affected. (See Appendix A.)
2) The potential for slope instability and its consequences, such as slope displacement, shall be evaluated based on site-specific material properties and ground motion parameters referenced in Subsection 1.1.3. and shall be taken into account in the design of the structure and its foundations.
[Rev. 7, B.C. Reg. 322/2009.]
1) Walls shall be designed to resist the lateral pressure
of the retained material.
1) Except where constructed in accordance with
Section 9.15., walls supporting drained earth
shallbe designed
a)for a pressure equivalent to that exerted by a fluid that has a density of not less than 480 kg/m3 and a depth equal to that of the retained earth, or
b) in accordance with Section 4.2. so as to be able to resist the loads and effects described in Article 4.1.2.1.
2) Walls supporting other than drained earth shall be
designed
a)for the pressure described in Clause (1)(a) plus the fluid pressure of the surcharge, or
b)in accordance with Section 4.2. so as to be able to resist the loads and effects described in Article 4.1.2.1.