Floorboards under bathroom wall rotted - help

20 Aug 2019
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United Kingdom
Long story short, wetroom placed by previous owner has leaked. I've removed the wetroom shower base to expose the joists to help dry it out.

The floorboards run under the wall from the bedroom next door. The floorboard ends in the bathroom have rotted through damp and had to be removed. This has left the wall , which sounds like a stud wall, unsupported at one end where the floorboards were affected (please see photo). How can I strengthen this area now the floorboard ends have gone? Noggin into joist?

I can feel the floorboard under the wall extends 8.5 inches from the joist.



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Without seeing it all, I can only give general advice. However, I think that you'll have to cut out the floor between the first joist next door and the wall. This needs to be done a bit at a time, installing short trimmer joists between the last joist on the bedroom side and the first joist in the bathroom, pulled up hard to the underside of the wall. These need be to about the same cross section as the original joists (e.g 7 x 2in not 3 x 2in CLS) and they also need to be screwed to the sole plate of the wall to prevent the new sections of floor from creaking. These infill pieces need to be at something likec400mm centres. Personally, I'd replace the cut away floor in the bedroom with something like 18 or 22mm hardwood plywood packed up to the existing floor level as needed

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