Ideas for beefing up butchered joists...

[John Rumm]

Not as hard as it sounds - if the notch has reasonably square sides, then use it mark lines on a filler block, cut to size and glue up before tapping in. If the notch is not clean, then mark it with a square and undercut the sides a bit:

Original rough notch: _________ ___________ | | |_-_|

Undercut the sides, and flatten the bottom (couple of saw cuts down, and chisel and mallet for the bottom) _________ ___________ / \ /________\

(Multimaster type tools are good for this sort of thing...)

Use the outline to mark you block, and cut a plug:

______ / \ /________\

You can now slap it in from the side, and it will restore the compressive strength at the top of the joist, while not working loose, or pulling out of the hole next time you lift a board.

Yup that would do it as well.

Whatever you do, will probably take longer than you expect!

[John Rumm]

I thought some illustrations of this might be useful, since its a handy technique for all sorts of applications. Hence:

(feel free to improve etc)

[TheOldFellow]

Great article. How did you do the illustrations?

R.

[Andy Burns]

By the looks of them

[John Rumm]

[TheOldFellow]

Ah, pity. Only runs on Microsoft and Mac. I tried it under Wine, but it whines a lot. Thanks. R.

[Andy Burns]

I just installed in on Wine on Fedora 11 with Intel945 graphics and it works almost perfectly, provided I edit the registry

HKEY_CURRENT_USER\Software\Google\SketchUp7\GLConfig\Display\HW_OK to be equal to 1 instead of 0

[TheOldFellow]

This key, nor the GLConfig section isn't in the registry here. Fresh install. Ubuntu 9.10 with NVIDIA. R.

[Tim W]

Why? wibbled on Saturday 10 October 2009 14:51

You've just given me an idea...

If I install 8' ply strips (ie strips from a full sheet) along my stacked joists and stagger the joints on each side (because the joist span is longer than 8') then I'll not only be re-inforcing the damaged bits, I'll be leaving them better than before.

I've got either 2 or 3 (think it's 2) full runs of stacked joists and a couple of very short runs in an alcove. Sounds like an excellent plan.

Someone said 12mm ply earlier I think - would people concur this is a good enough thickness?

I might board my roof voids (on 4x2" ceiling rafters) with 18mm ply cut into wide (say 2') boards. Still easy to lift but screwed down it should stiffen the floor so I could get away with extra weight without bending the ceilings... I do plan to put as much crap as possible in those areas (each area is about 2m2 and there's 4 of them plus a few smaller bits)

Excellent stuff - thanks...

[dennis]

That's what I said earlier when someone said their roof was too thin. do it in thinner ply two on each side with joints staggered and it will be even stronger. Add a strip of metal into the sandwich and its even stronger.