The Ontario Building Code | Deflections

9.4.3.1. Deflections

(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)

Item	Column 1 Structural Members	Column 2 Type of ceiling Supported	Column 3 Max. Allowable Deflection as an Expressed Ratio of the Clear Span
1.	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
2.	ceiling joists	Other than plaster or gypsum board	1/240
		plaster or gypsum board	1/360
3.	floor beams, floor joists and floor decking	All cases	1/360
4.	Beams, joists and decking for balconies, decks and other accessible exterior platforms	Serving a single dwelling unit	1/240
		Other	1/360

Note: On July 1, 2017, item 4 of Table 9.4.3.1. of Division B of the Regulation is amended by striking out "single dwelling unit" in Column 2 and substituting "house or an individual dwelling unit". (See: O. Reg. 139/17, s. 71)

9.4.4. foundation Conditions