Code Library › Volume 1 › Section 9.30 — Flooring
PART 9 — HOUSING AND SMALL BUILDINGSUpdated for the 2024 Ontario Building Code

9.30.2.2.Materials and Thickness

(1) Panel-type underlay shall be not less than 6 mm thick and shall conform to (a) ANSI A208.1, “Particleboard,” (b) CAN/CGSB-11.3-M, “Hardboard,” (c) ANSI/HPVA HP-1, “American National Standard for Hardwood and Decorative Plywood,” (d) CSA O121, “Douglas fir plywood,” (e) CSA O151, “Canadian softwood plywood,” (f) CSA O153, “Poplar plywood,” or (g) CSA O437.0, “OSB and Waferboard.”
← Previous9.30.2.1. Required UnderlayNext →9.30.2.3. Fastening

Common questions about this part of the code

How thick does the subfloor need to be in an Ontario house?What kind of finish flooring is required in bathrooms and laundry rooms in Ontario?

Understand this provision in seconds

BUILDAiD Assist explains any article of the building code in plain English — with exact citations, exceptions and related requirements.

Try BUILDAiD Beta

Code text is reproduced for reference from the Ontario Building Code (O. Reg. 163/24, 2024 Building Code Compendium). This page is provided for general information and is not an official copy. Always verify requirements against the official Ontario Building Code and confirm with your local building department.