Repairing Water-Damaged Floor Joists

[lesrico]

After a leak under my bathroom shower tray I need to repair 2 or possibly 3 floor joists. Unfortunately, the leak was a steady trickle over a couple of years which has ruined the ends of the affected joists (rotten!) along with approximately 1m2 of floorboards.

I have removed shower tray, plywood & floorboards to expose the joists which are at 14" centres. They are laid on dwarf walls that run perpendicular approximately 2ft centres.

The rotten part of each joist only extends about 12" from the butt end of each one and after this point the timber appears to be in perfect order (I'm not 100% certain of this!) so, ideally I'd like to replace a minimal section of each joist to keep the costs down.

Is there recommended/minimum length of the joist I will need to remove beyond the rotten timber? If so, what is the recommended method of replacing, i.e. how do I attach new section to existing joist?

I don't have enough funds to pay a builder so I need to make good myself so any advice on how to undertake the works would be greatly appreciated!

Many thanks in advance!

Lee.

 

[Lower]

Are the rotten ends of the joists embedded in the wall or do they also rest on the sleeper walls?

If they rest on the sleeper wall i would sister another joist alongside the existing one with at least 1m of overlap past the end of the rot.

Coach bolt the joists together. Minimum of 3 bolts per joist with large spreader washers.

I have done similar in the past with good results.

 

[lesrico]

Are the rotten ends of the joists embedded in the wall or do they also rest on the sleeper walls?

If they rest on the sleeper wall i would sister another joist alongside the existing one with at least 1m of overlap past the end of the rot.

Coach bolt the joists together. Minimum of 3 bolts per joist with large spreader washers.

I have done similar in the past with good results.

Yes, they are just sat on wall, butted up to blocks. So you think a minimum of 1m is necessary? Wow - I have my work cut out!!

Thanks very much for advice!!