Trying to avoid significantly notching a joist (help required)

[Seri]

I have a nice heavy cast stone hexagonal shower tray that I'm shortly going to be fitting into the upstairs bathroom. Unfortunately I've just measured up from the wall to the hole for the waste trap and wouldn't you just know it, but it's straight on top of a joist.

The joist in question is 165mm deep and the trap I have for it is going to go down 85mm into it. I really don't want to notch a joist past the half way mark due to how much this is going to weaken it but I can't bring the shower tray out from the wall as then the new bath won't fit.

As far as I can tell, this leaves me with two choices. One is to raise the shower tray be enough to accommodate the waste trap and pipe beneath it. The other is to notch the joist and then strengthen it after the fact, this is my preferred solution. So, is this feasible, and if so, how the heck could/would/should I do it?

As ever, any and all answers or suggestions would be extremely gratefully received.

Thanks

Seri

[Stuart]

Would a pair of U-Shaped steel plates bolted through the joists do .?? When I say U-shaped I mean a square U so that the plates fit both below and to each side of the notch ....I presume that you cannot get access to underneath the joist otherwise I would have suggested getting a support made up by a local metal workshop so that the U shaped plates were joined ( welded) underneath as well to give additional support . Stuart

[Rob Morley]

You could completely remove that section of joist and support the cut ends with a couple of lengths fixed to adjacent joists with hangers, as you would with a loft hatch.

[Lobster]

Do you have a good reason not to want to raise the tray? A lot easier than strenthening that cut joist (IMHO a must, by the way!). It's my preferred method regardless of the position of the joists, because it gives you access to underneath the tray later on, when you're trying to unblock a waste pipe/ascertain why the ceiling is damp below the shower(!) etc etc. It's just a matter of standing the tray on a slab of .75" WBP ply, which stands on 4 lengths of 4x2 timber; cover the front access area with a removable bit of skirting board or uPVC.

David

[Rob Morley]

Or extend the platform in front of the shower as well to avoid a big step when you're getting in and out (makes access trickier but avoids the objection that some people have to a raised shower tray).

[John Rumm]

Option 1: Raise the tray

Option 2:

Starting with (top down view of joists):

# # # # # # # # # # # # # # # # # # # # # # # #

Use a stringer to take the end of the joist and cut a bit out

# # # # # # ############## # # # # # # # # # # # #

[Seri]

Thanks for the replies. I wasn't sure that a stringer supported from joist hangers attached to the existing joists was recommended. But thanks to everyones good advice I shall be going to my friendly neighbourhood hire shop and getting some acro's next week.

Thanks again.

Seri

[Weatherlawyer]

I think you are very silly not going with the raised tray idea. You are talking about 2 hours work vss a day or so. And a poorer job all around.

Do as you were told idiot.

One thing, make the dais "E" shaped and (with the supporting ply) the height of a tile. You can accomplish this with packers. You might even be able to get over the skirting board and any other things perhaps yet to be discovered.

This way you get to be able to adjust the slope in the future.

Your way sucks.

[John Rumm]

If the joist in question is not that heavily loaded (which seems likely in a bathroom), you can do it without acrows...

# # # # # # ############## # # # ============== A # # # # # #

Just lay a 4x2" across the joists (wide aspect facing up) a bit back from the cut, and screw it down into the joist you are about to cut.

That coupled with the floorboards that may also be nailed to it should keep it in place for long enough to get a stringer in place.

(remove when done obviously ;-))

[John Rumm]

Well to be fair I could do either in a couple of hours...

Oh, that told him big boy!

Has it not occured to you that there may be a reason why raising the tray is a non starter?

[Chris Bacon]

Erm, "brusque" is perhaps inadequate...

Erm.... the OP is a dwarf?

[Steve Walker]

Why not turn the tray 90 deg and see if that projects the trap into clear space?

[Seri]

Righty, just to clear up confussion and banter. As the tray is a hexagonal one it can't be rotated and can only go in one direction/rotation.

The reason I don't want to raise the shower tray if at all avoidable is that the ceiling in the bathroom at the point where the shower will be slopes downwards and by my calcs the shower will only just be comfortable to use if the head is as high as possible and the shower tray as low as possible.

As it happens I've been sat here with my materials and measures and may just be able to reclaim the 50mm required to shift the shower tray over a small ammount and make this entire thing a non starter, but I'm still not 100% confident.

Once again, thanks for the replies and help, at least now I have more options available to me if nothing else.

Thanks again

Seri

[John Rumm]

Can you get a bit more space by hacking a bit out of the wall to set the tray into it a little?

(This is actually quite a nice idea anyway since it makes the job of ensuring the tiles drain down onto the tray with a little overlap, preventing any chance of water ever getting down beside it.