Shortening a bathroom floor joist

[pjo123]

Hi all

Best described by pics below (not at all to scale), am installing a U shaped shower in my bathroom, unfortunately, the stone resin shower tray has the waste over the top of one of the joists.

I could raise the shower but would prefer not to.

As I already have the ceiling taken down in the room below, hence have access to the joists, is it possible to shorten a joist by about 6 inches and have it fixed via joist hangers into the adjoining two joists, as per my second pic.

If it helps. 1930s house with 6x2" joists

Many thanks.

Pic 1 showing a rough drawing of where the shower is going and how the joist is in the way

Pic 2 showing what I'd like to do with the joist

 

[noseall]

The trimming arrangement looks ok in principal but structurally it leaves the supporting joists with more work to do. If you are maxed out on span and spacings then this would usually mean doubling up on the joists either side of the trimmer.

Everything else, i.e. hangers etc is spot on.

 

[xr4x4]

i would do what you are suggesting but add another small joist from the trimmer to the wall alongside the shower tray trap.

 

[gregers]

wouldnt it be advisable to sister the joists either side of the trimmer.

 

[hotrod]

Why don't you just move the joist 50mm to the left or right so it doesn't foul the waste/trap arrangement?

 

[^woody^]

wouldnt it be advisable to sister the joists either side of the trimmer.

Why not just sister the single joist which is to be cut for the waste trap?

 

[geraint]

wouldnt it be advisable to sister the joists either side of the trimmer.

Why not just sister the single joist which is to be cut for the waste trap?

why always mention my sister.......

she is a good girl really....

and better than me....

 

[joinerjohn]

I came home the other day to find a blonde woman regrouting the shower in my bathroom. She was singing at the top of her voice "It's a heartache,,, nothing but a heartache."

I thought to myself,,,,, Shes a bonnie tiler.

 

[Alastairreid]

I came home the other day to find a blonde woman regrouting the shower in my bathroom. She was singing at the top of her voice "It's a heartache,,, nothing but a heartache."

I thought to myself,,,,, Shes a bonnie tiler.

lol...i liked that.

 

[hotrod]

I came home the other day to find a blonde woman regrouting the shower in my bathroom. She was singing at the top of her voice "It's a heartache,,, nothing but a heartache."

I thought to myself,,,,, Shes a bonnie tiler.

You daft apeth jj

 

[pjo123]

Many thanks all

I will add a small joist alongside the trap as suggested.

Sistering the actual joist will still be too tight against the hole.

Only problem I'm going to have with sistering is the pipework running through the joists, having to cut, remove and replace it to sister the joists, will be a pain to put it mildly.

I understand the extra work the two supporting joists will have, however in other parts of the house when I've replaced the lathe and plaster ceiling, in a few places there's been similar things done when the house was built, and none of these have doubled up joists, and some of these are supporting a lot more weight than the area I'll be trimming the joist from.

I did sister up one of the joists elsewhere a few weeks ago as it had so much extra stuff sitting on it, plus it was easy to remove the cables, I thought it's best to be safe. But even this had been in since it was built with zero problems.

The span is fairly short, 8.5ft wall to wall. The shower will be on 18mm ply sitting on top of the floor boards so the weight is spread.

All the above taken into account, I hope I can get away without sistering up the joists?

Many thanks

 

[theoldun]

2.525 long 50x150mm joists at either 400 or 450 centres are well inside your limits and will quite comfortably trim all as your sketch.
Just out of curiosity where are you going to run your waste?
oldun

 

[pjo123]

Thanks.

Have ended up doing the following, adding two small joists either side of the hole.

There's a hopper for the bathroom sink about 5ft to the right of where the hole is for the shower trap, so I intend to go straight through the outside wall and go diagonally right into it.

Am going to go through the wall into one of these T's

http://www.screwfix.com/p/floplast-solvent-weld-40mm-tee-black-pack-of-3/64518

and put an access plug into the end at the top right of the pic.

That means with a showertrap that has top access, and me being able to get straight into it from the T, hopefully if it does ever get blocked, it shouldn't be too hard to get into even though it's under the floor.