The Ontario Building Code | Deflection
(1) In proportioning structural members to limit serviceability problems resulting from deflections, consideration shall be given to,
(a) the intended use of the building or member,
(b) limiting damage to non-structural members made of materials whose physical properties are known at the time of design,
(c) limiting damage to the structure itself, and
(d) creep, shrinkage, temperature changes and prestress.
(2) The lateral deflection of buildings due to service wind and gravity loads shall be checked to ensure that structural elements and non-structural elements, whose nature is known at the time the structural design is carried out, will not be damaged.
(3) Except as provided in Sentence (4), the total drift per storey under service wind and gravity loads shall not exceed 1/500 of the storey height unless other drift limits are specified in the design standards referenced in Section 4.3.
(4) The deflection limits required in Sentence (3) do not apply to industrial buildings or sheds if experience has proven that greater movement will have no significant adverse effects on the strength and function of the building.
(5) The building structure shall be designed for lateral deflection due to E, in accordance with Article 220.127.116.11.