Cast-in-place Foundation Walls

Place concrete continuously without interruption. Tamp or vibrate the concrete to remove air pockets and to work the material around and beneath window frames and other blocking.

Anchor bolts for sill plates should be placed while the concrete is in an unhardened condition. Such bolts are at least 12.7 mm (1⁄2 in.) in diameter, spaced no more than 2.4 m (8 ft.) apart (Figure 40) and embedded at least 100 mm (4 in.) into the foundation wall. The ends should be deformed or bent to provide secure anchoring. The bolts themselves should be free of oil, and the concrete should be cured before the bolts are tightened.

Wood-frame buildings with two or more floors situated in areas of high exposure to wind or earthquake require additional anchorage, specifically 12.7 mm (1⁄2 in.) bolts spaced not more than 1.7 m (5 ft. 6 in.) on centre or 15.9 mm (5⁄8 in.) bolts spaced not more than 2.4 m (8 ft.) on centre. In both cases, the first anchor bolt must be located within 0.5 m (1 ft. 8 in.) of the end of the foundation and there must be at least two anchors per braced wall panel. Engineering design is required for the anchorage in areas with extreme earthquake or wind loads.

Figure 40

Method of anchoring floor system to concrete walls, showing anchor bolt for
wood sill

Source : Canada Mortgage and Housing Corporation (CMHC)