A beam may be considered to be laterally supported if wood joists bear on its top flange at intervals of 600 mm or less over its entire length, if all the load being applied to this beam is transmitted through the joists and if 19 mm by 38 mm wood strips in contact with the top flange are nailed on both sides of the beam to the bottom of the joists supported. Other additional methods of positive lateral support are acceptable.
For supported joist lengths intermediate between those in the table, straight line interpolation may be used in determining the maximum beam span.
Design Assumptions for Tables 9.23.4.3.-A to 9.23.4.3.-J (Steel Beams Supporting Roofs and Floors)
1.
Density of Brick Veneer:
- Brick = 18.9 kN/m
3
2.
Dead Load of Brick Veneer:
- 89 mm Brick = 0.089 x 18.9 = 1.68 kPa
- Brick loading on beam = 3 m high brick x 1.68 = 5.04 kN/m. This is based on a single storey wall with windows and a brick gable above the top of the stud wall. In this case, the windows in the exterior wall nullify the arch action of the brick and the load is applied uniformly along the length of the beam.
3.
Dead Load of Structure:
- Roof = 0.62 kPa (Asphalt shingle roof)
- Floor = 1.5 kPa as per Appendix Note A-Table 9.23.4.3.
4.
Live Loads:
- Floor = 1.9 kPa
- Roof = as indicated in the Tables
5.
Design Standards:
- CSA S304.1-94, “Masonry Design for Buildings (Limit States Design)”
- CSA S16.1-94, ‘Limit States Design of Steel Structures”
6.
Design Assumptions:
- Simply supported beam spans
- Laterally supported top flange
- Yield strength 300 MPa
- Mid-span deflection limited to span/600 as per Clause 6.3.5.1 of CSA S304.1, for brick weight plus live load. The self-weight of structure is typically on the beam prior to the application of the brick so the deflection check need only include live and brick loads.
- For siding walls the mid-span deflection is limited to span/360 on live load.