Pipe through roof

[bmb4cjt]

Hi,

We're in the middle of building and side extension. At the front there is to be a pitched roof (approx where the dotted line is on the picture). I understand that the 110mm soil pipe is able to pass through vertically using a lead tile or something similar. But how about the 40mm horizontal bath pipe what will run through also can this be done in a similar way or need a rethink of the pipework?

Cheers

 

[johnny2007]

Can you move those 40mm pipes inside and join them to the 110mm straight out of the wall?
That would also give you a chance to go for a joined run of 50mm pipe so to avoid gurgling and blockages.

 

[bmb4cjt]

Think that might end up being the best solution, means a fair upheaval in the bathroom to fit the new pipework which we could do without atm as hasn't planned on redoing that room for a while. If it needs to be done it needs to be done tho. I can't see how a horizontal lead tile wouldn't leak or be a pain if the pipe needs changing in this case.

 

[Madrab]

The best idea would have been to move the soil pipe and drain before the slab was poured.

The main issue with that will be if you ever have an issue with the soil pipe or main drains. Is there an inspection hatch anywhere in that foundation? Has BC seen that and are they happy with it?

 

[bmb4cjt]

Hey @Madrab,

You mean run the SVP infront of the foundation? Where the pink line is?

BC saw drains when the groundsworkers were in and happy for them to continue.

There is an inspection chamber just out of view to left of the foundation wall and I've since fitted a access socket to the base of the SVP for rodding. The room X is gonna be a downstairs loo with sink on the wall closest that pipe and was going to boss the sink into it.

 

[Madrab]

Of course this all great in hindsight. Yes, I think that would have been a more effective approach rather than having to run the SVP through the roofline and having any part of the main drain underneath concrete founds.

If BC saw it and were happy then fair enough, given then is an accessible chamber makes things a lot happier of course. Personally though I would have tried to avoid having any part of the main drain under concrete if there were any issues in the future, if it could have been at all avoided and by the sounds of it it could have been.

Any reason you can't run the the 40mm waste to the left slightly, then down to enter the extension through the vertical wall rather than making another break through the roofline? You really want to minimise any breach on the roof to wall joints, as it's a point where there can be possible water ingress when things settle and move over the mid to long term, as older walls and new extensions invariably do.

 

[bmb4cjt]

Tbh I could still reposition the SVP, I've dug a trench to replace lead water line with MDPE and it's revealed most of the inspection chamber and drain anyway. The slab atm needs insulation, UFH and screed yet so could just discontinue that small section of pipe and bury it under the floor and start new outside.

Cheers for your help