The Ontario Building Code | Elements of the Second Plane of Protection
9.27.3.1. Elements of the Second Plane of Protection
(1) The second plane of protection shall consist of a drainage plane with appropriate inner boundary and flashing to dissipate rainwater to the exterior.
(2) The inner boundary of the drainage plane shall comply with,
(a) Articles 9.27.3.2. to 9.27.3.6., or
(b) Subsection 9.27.13.
(3) The protection provided by the second plane of protection shall be maintained,
(a) at wall penetrations created by the installation of components and services such as windows, doors, ventilation ducts, piping, wiring and electrical outlets, and
(b) at the interface with other wall assemblies.
(4) Flashing material and installation shall comply with Articles 9.27.3.7. and 9.27.3.8.
In Plain Language
The elements making up the second plane of protection, the backup system behind the cladding, are described in this article, including the sheathing membrane and flashing.
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.