How do i replace this rotted subfloor in my bathroom?

Question

I am remodeling my bathroom and when I torn out the old tile i saw a severely damaged subfloor. It's not wet but had been. The rot is all around the toilet and bathtub areas and at some points goes underneath the non structural walls between rooms. I know I should cut out the bad areas and start over but what do i do about the areas of subfloor that are rotted underneath the walls? These walls are resting on joists that do not appear to be damaged, but the subfloor is soft and flaking apart. Can i suport the joist with sisters and place a new sub floor or do i need to tear down the walls and go back to a point on an adjacent joist, replace the subfloor and rebuild the walls?

Answer 1

I would try to sister the joist first. see how well that is able to grab a screw. then you will have some meat to screw too. That would prevent u from tearing down walls. You sound like you know what your doing. Go with the scab or sistering of the floor joist first. good luck

Answer 2

your best bet may be to replace the whole floor. you should rip out the walls too so you can really see the condition of the joists....they may be more damaged than you can see at this point. replace, redo and rebuild is the best thing to do with water damage. good luck.

Answer 3

Crash boom bang...sorry.

Usually this is only the tip of the iceberg. Probably you will find a world of hurt once you start removing tiles and the floor.

There must be a problem that needs fixing. As long as you have not found this the problem will only get worse with half backed solutions. If the problem was not water related you probably could get away with less but this calls for desperate measures.

Answer 4

I'm a tile-setter, it would take me a day or less to rip everything down to the sub floor. If the plywood is good, I leave it alone or install new over the old providing the old isn't moldy or damage. There is a web site that give you step by step installation tips to install tile flooring. Go for it and Good Luck

Answer 5

As you well know, anytime you are replacing rotten wood, you MUST tear back to the first good wood you find. If you don't do it now you will just have to do it later.