Outlet boxes, cabinets, and fittings (see Appendix B)
1) The front edges of boxes, cabinets, and fittings installed in walls or ceilings shall not be set in more than 6 mm from the finished surface and, where the walls or ceilings are of wood or other combustible material, shall be flush with the finished surface or shall project from the surface.
2) Gaps or open spaces in plaster surfaces of walls or ceilings shall be filled in around the front edges of boxes, cabinets, and fittings.
3) Outlet boxes requiring wet location cover plates shall be installed in a manner that the intended seal between the outlet box and the cover is ensured.
4) Flush boxes, cabinets, and fittings shall be of a type suitable for the intended location of installation.
Source: Rule 12-3016, CSA C22.1:21, Canadian Electrical Code, Part 1 (25th Edition), Safety Standard for Electrical Installations. © 2021 Canadian Standards Association. Please visit store.csagroup.org