Dry Rot in Bathroom Walls - August 29th 2005

Dry Rot in Bathroom Walls

Q: My wife and I have been doing some work on the bathroom in our 25-year-old house. We removed the baseboards and right beside the bathtub we found wallboard that was crumbling to pieces from exposure to water. After removing the crumbled wallboard we took a pen knife and were easily able to stab it into the 2 X 3 toeplate to a maximum depth of 1 inch, we assume the wood has rotted. (By toeplate we mean the board that the 2 x 3 wall framing sits on), The rot appears to be a few inches wide, and about an inch up from the plywood that forms the floor. We wonder if the rot will continue to spread through the framing even if we prevent water from getting to it in future? Should we replace the toeplate as soon as possible?

A: Dry rot in wood is caused from constant dampness that forms a fungus turning to rot. Stop the leakage of water and the rotting will stop as long as the wood is dried out before closing up the area with drywall or cement board (Dens-shield). If this wall (lower plate) is on a partition wall it will more than likely be a non-bearing load wall that could easily be removed and replaced with treated 2 x 4's. However I would suggest that you leave it rather than disturb it. To speed up the drying process you can use a hair dryer for a very small area like you have outlined. If after leaving it open for a week you can still notice a wet wood smell spray with the Shell Busey "It's Just That Easy Odour Remover" available at most Building Supply stores i.e.: Windsor Plywood, Home Hardware etc.