bathroom waste through joists

[Raf75]

Hi,

I know that the first thing that comes to mind is not to do it – if can be avoided.

However I don’t think it can…

I’m planning to do as per attached drawing, in a photo the connection to the main waste stack is slightly different as I realized it will need a hole in the joist outside permitted zone.

Can you please give your opinion/suggestions?

Many thanks in advance…

 

[footprints]

In a word no
If that is an outside wall you might be able to take the waste out through the wall and do your coupling across there perhaps.
Another option of course is a saniflow but I wouldn't wish one of those on anybody.

Best answer might be to raise the shower base on a plinth and run in the void

 

[Raf75]

Would you mind to explain in a few words what is the problem?

There is no option to take it outside as it is an internal wall.

But even with the raised shower base there would still be a problem with the basin waste?

 

[Raf75]

The joists are 170mm x 47mm – I understand that allowable hole through the centre is 42.5mm – ours will be 45mm, but the joist here are much denser than 40cm centres so shouldn’t that help?

 

[just pumps]

[QUOTE="footprints, post: 3765276, member: 174063"
Another option of course is a saniflow but I wouldn't wish one of those on anybody.
[/QUOTE]

I wouldn`t fit a Saniflo either, well not without knowing the specs of the shower.

 

[Raf75]

Does anybody else have an opinion on this?

Many thanks….

 

[John D v2.0]

Your logic is flawed! There's not guaranteed to be a nice solution that you can find in all situations!

Having said that, what's underneath? Either box it in below or lower the ceiling a couple of inches. We're about to do exactly that for our pipes as the joists are half way notched and the floor is like a drum.

 

[Raf75]

Our joists are brand new, without any other notches, holes or other damage.
why is the logic flawed... ? I know there isn't always a good solution - I only want to find one for my situation

 

[John D v2.0]

I was just messing with you! Just sounded like you were saying there's no other solution so there must be a way to notch! Good luck with it though, perhaps you can switch a few to engineered joists with holes in between