Loft conversion running waste

[J murton]

Hi
I’m after some advice about the pipework for my loft conversion.
I am having a bathroom on the right side of the loft and the waste will need to run through all of the floor joists (red line) to pick up the stack which is on the gabel end.
My question is can I drill through all these joists and still meet building regs ? I can’t see any other way of running the waste for the shower and basin as I want the shower sitting on the floor.
Due to length of run being over 3 meters it should be run in 2 inch but will 11/2 suffice ?
Thanks

 

[Murdoch]

Ask your BCO ?

 

[Roy_66]

Mitek Posi Joists?

 

[Deleted member 120897]

A bit dated, but don’t think it’s changed? How to get it right: Notches & holes in solid timber joists | LABC - https://www.labc.co.uk/news/how-get-it-right-notches-holes-solid-timber-joists?language_content_entity=cy

 

[oz-plumber]

Not sure of your regs but we would have to run a minimum pipe size of 65mm for shower and basin over that distance.
Saying that, I would never run a shower off a 40mm waste pipe.

Where is the toilet going and how is that waste run?

Connect into that waste pipe

 

[Jmmmmm]

Well 65 mm isn’t standard. 50mm would be next size up. But due to building regs max size of hole that can be cut into those floor joists is 47 mm. Toilet waste will be run in the eves. I wanted to have the shower tray on the floor.

 

[ShaunCorbs]

Yes you can drill them aslong as you follow the rules on drilling as there not loaded full eg the steels are doing this

2” would be my recommendation so you need at least a 8” timber there

 

[gpbeck]

Any way to rework the ceiling below, only load is presumably the plasterboard?

 

[king of pipes]

I wouldn't be drilling them all keep the 110mm soil pipe back in the eaves with a gentle fall to the gable you should be able to connect into that as below i would keep it 40mm with long radius bends and a highflow waste outlet on the shower tray run the sink and shower waste separately something like i did on this one

 

[ShaunCorbs]

I wouldn't be drilling them all keep the 110mm soil pipe back in the eaves with a gentle fall to the gable you should be able to connect into that as below i would keep it 40mm with long radius bends and a highflow waste outlet on the shower tray run the sink and shower waste separately something like i did on this one

He’s having a flat / low level shower tray so either pump or run through timbers