Rotting Joists

[OBBob]

Hi All

Whilst working something else I came across a couple of joist ends on the outside edge of the house that had rotted to the extens that they had squashed under load.

This section of teh house is very low, so getting under isn't really an option. The stumps etc ahve already be re-done and all the other timber looks fine. There are no issues like cracking etc in side, so its just a case of making sure it doesn't get worse.

- Is my only option to cuts some blocks to to fit between the bottom plate and bearer to take the load?
- I guess if I can get it in there ideally I would run an additional joist to the next bearer ... but as I said access is an issue.
- What is the best product to apply to the rest of the timber ends to make sure they don't go this way in the furture?


Thanks.

[echnidna]

Blocking between plates and joists is a good idea.

Saturating the rotten ends of the joists with white king will kill the mould that decays the timber. But it doesn't waterproof the timber. So after it dries out I'd give the ends a few coats of Cabot's Bar-D-Kay which not only protects against future decay it also waterproofs the ends. You might not even need the white king but given the cost it doesn't hurt to go overboard.
The only thing with these treatments is that the timber needs to be dry so it might be a job for late summer.

Assuming the floor joists are 4" wide you could add new 3" x 2" (75 x 50) joists alongside the originals. Packing the outer end is easy enough. You would need to figure out how to pack the inner end up from the bearer, maybe a bit of 2" x 1" long enough to tap in on a bit of an angle and just leave the excess length there.

Another way to fit a new joist is to plane a section off the bottom of a 4" (100mm) joist between where the joists sit on the bearers so you knock it in all the way (a reasonably firm fit is needed between bearers and floor)

Use secondhand hardwood for the new joists as its already finished shrinking.

[OBBob]

Thanks Bob

Do you know of any protective timber treatements that have that soak in effect but allow you to paint the wood afterward? So soemthing a little more adavnced that just coating with solar guard?

[echnidna]

you can paint over bar-d-kay