Replacing rotten subflooring is a sizable project requiring skilled labor, plywood, lots of time, and equipment such as circular saws and crowbars. If no crawlspace is present to provide access to the subflooring, it may also entail tearing up existing floor.Continue Reading
Subfloors provide a solid, level footing for the placement of a floor covering. The floor covering provides a pleasing appearance and a reliable, easily cleaned walking surface for a structure's occupants. Subfloors may also incorporate a house's plumbing and electrical systems.
Before proceeding with repairs, enter the crawlspace to determine how far the rot has spread. If it is localized, removing only the affected portion of the subfloor with a circular saw and replacing it with new plywood may solve the problem. If it is widespread, more drastic measures are called for.
Pry up the floorboards with a crowbar and cut out the rotten subflooring with a circular saw. If the joists are still sturdy, replace the rotten subflooring with new plywood cut to fit the space in question and then nail down the new wood. It is possible to nail new plywood into place onto rotten subflooring, but this only buys time as rot and mildew will spread and corrupt the new wood.