Foundations & Concrete Formwork
Foundation types, concrete formwork systems, sill plates, anchor bolts, and mudsills in Canadian construction.
- Identify the common foundation types used in Canadian residential construction
- Describe the components and construction of concrete formwork
- Explain the purpose and installation of sill plates and anchor bolts
- Apply NBC requirements for foundation depth and frost protection
Leçon 1
Foundation Types & Systems
Why Foundations Matter
The foundation is the most critical structural element of any building. It transfers the weight of the entire structure to the ground and must resist soil pressure, moisture, frost heave, and seismic forces. In Canada, foundation design must account for frost depth - which varies significantly by region.
Foundation Types
Full Basement
Walls: Poured concrete or block
Depth: Below frost line (full height)
Advantage: Usable living/storage space
Common in: Most of Canada
Crawl Space
Walls: Poured concrete or block, short height
Depth: Below frost line
Advantage: Access to services below floor
Common in: Milder climate regions
Slab-on-Grade
Walls: Thickened edge or frost wall
Depth: Grade level with frost protection
Advantage: Most economical
Common in: Garages, mild climates
The type of foundation that uses poured concrete walls is the full basement or crawl space. Poured concrete is the most common foundation wall material in Canadian residential construction because it provides strength, moisture resistance, and a monolithic structure. A slab-on-grade uses a concrete slab rather than separate walls.
Footings
Footings are the base of the foundation system. They spread the building load over a larger area of soil. Key footing requirements:
- Width: Typically twice the wall thickness
- Depth: Minimum 150 mm (6 inches)
- Reinforcement: Steel rebar as required by design
- Placement: On undisturbed soil below the frost line
Poured Concrete Walls
The foundation type that uses poured concrete walls is the full basement or crawl space. Slab-on-grade foundations use a thickened concrete slab instead of separate walls.
Full basements and crawl spaces use poured concrete walls. Footings must be below the frost line and on undisturbed soil. Foundation design in Canada must account for regional frost depth.