3m bondo all purpose resin

[cherv]

Has anyone used it to patch a sub floor non structural area under the protective plastic sheeting...under the shower area the plywood is delamanating/ flaking loose. No leaks but possible condensation. An area about 2 ft by 1 foot. Thinkng of using resin and fiberglass cloth...comments

[BFlinn181]

I'd strongly recommend cutting out the damaged plywood and replacing it. Covered up with resin, the damaged wood will just continue to rot and weaken the structure. I've seen it with boats and homes, it's not a repair, it's a band-aid.

[60sumtin]

Originally Posted by cherv

Has anyone used it to patch a sub floor non structural area under the protective plastic sheeting...under the shower area the plywood is delamanating/ flaking loose. No leaks but possible condensation. An area about 2 ft by 1 foot. Thinkng of using resin and fiberglass cloth...comments

That doesn't sound like condensation. How could it be humid under a shower if there is no leak? Water is getting under there somehow and from somewhere.

I agree, Bondo is not a proper repair and the damaged wood needs to be cut out and replaced but the source of the leak has to be found first otherwise you are wasting your time.