mobilehomerepair.com

Just bought my first MH, a 1995 model. I decided to remove the carpet from master bathroom to find wood rotten between vanity & tub (plywood floor). I cut this section out to find, what I would call, the main frame (running front to back) rotten & 2 cross joists also rotten at the ends. There is no apparent leaks from either the sink or bath to have caused this. I checked the roof & cannot find any damage. There is an outside seam very close to this area, but the seam looks in good shape. Any suggestions are welcomed.

Check your plumbing connections from top down, repair/replace as necessary. Look on tub faucets, toilet feed/flange, shower feed too. Do you have a roof vent above your master bath??
When I bought my mobile, it had a leaky toilet flange that rotted out most of the bathroom floor. The cause could also be from a previous owner's repeatedly overflowing toilet or "splashy" kids in the tub/shower, and the carpet "covered" the water leaks/damage. If you have that serious of damage its been leaking in some way for years.

As for repairing the structure, Id sister in new joists on either side of whats rotted out, then glue and screw new plywood to the new joists. Id also rip out any insulation under that part of the floor(its probably wet and moldy) and replace.

It is possible that the damage is from an old leak that was sealed but not fully repaired. Some people will fix the leak but go no farther to repair the damage caused by the leak.

As Bob said, repair the joists and put new subflooring down.

Greg

im in the same boat with my place, easiest to just start fresh right from your metal frame up, that way going forward at least you know you have a solid floor under you, mines from years of just about everything leaking lol