The Ontario Building Code | Required Underlay
9.30.2.1. Required Underlay
(1) A panel-type underlay shall be provided under resilient flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring, parquet flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring, ceramic tile, felted-synthetic-fibre floor coverings or carpeting laid over lumber subflooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring.
(2) A panel-type underlay shall be provided under resilient flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring, parquet flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring, felted-synthetic-fibre floor coverings or carpeting on panel-type subflooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring whose edges are unsupported.
(3) panel-type underlay shall be provided under ceramic tile applied with adhesive.
(4) panel-type underlay shall be provided under resilient flooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring on waferboard or strandboard subflooring="http://thehandyforce.com/flooring/" title ="Handyman flooring install Toronto">flooring.
In Plain Language
An underlay is required beneath certain finish flooring materials, as set out in this article, providing a smooth, stable base.
This is a plain-language summary of the 2012/2017 Ontario Building Code text above, for general understanding only and not a substitute for the Code. Always confirm current requirements against the 2024 edition (O.Reg. 163/24) or a qualified professional before construction.