At what supported joist span do the basic footing width tables stop applying?
The prescriptive footing width tables stop applying once the supported joist span exceeds 4.9 m.
Conditions and exceptions
- Beyond that span the footing must be designed rather than taken from the table.
- Supported joist span is not the same as the joist length — check how it is measured.
- Soil bearing capacity governs independently of span.
Where this comes from
National Building Code of Canada — Part 9
This page states the requirement and points you to the publisher. It does not reproduce the code text — read the provision itself at the official source below.
Read the official text at NRC — Codes Canada publications →Verify this against the code edition actually adopted where you are building. Provinces, territories, and municipalities amend on their own schedules, and where the governing document and this page disagree, the governing document controls. This is not legal, engineering, or permitting advice. Last reviewed 2026-08-12.
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