Cross flow with new internal soil pipes

[john-diy!]

Plumber has fitted internal toilet soil pipes in the downstairs hall opposite each other into a Y connector, before entering the soil stack pipe. Now there is a risk of cross flow, but there is only one hole (above a lintel) for access to soil stack, so the soil pipes cannot be staggered into the soil stack. Building regs will not sign this off, until it is resolved. Access to the soil stack is complicated, that is presumably why the plumber chose to use the existing hole above the lintel. (see attached photo which show the issue). Plumber suggested placing a valve/trap door to prevent cross flow putting in a hatch to access the soil pipe, to make it easier to rod. However, I believe it will still not pass building regs. The new soil pipe connected into the "Y" is at the correct gradient and is 4 meters long and the existing soil pipe is going almost vertical into the "Y" , so plumber thinks its very unlikely to have sufficient cross flow to over flow. Also concerned about "watershed " at the junction if both toilets flush at the same time- will it be more likely to block at the "Y" junction. Any ideas please.

 

[Hugh Jaleak]

Building regs will not sign this off, until it is resolved.

I am not surprised, it's a blockage waiting to happen! It's up there with the best best, an absolute bodge. Did your Installer, (as they don't deserve the title of Plumber), arrive on Horseback?

Now there is a risk of cross flow,

Risk? I'd say a certainty. There is no way there can be an adequate fall from both directions, it's a blockage waiting to happen, the only variable would be how long it takes to block....

Any ideas please.

You might just get away with using a double Branch, at least then both connection are swept in direction of flow, but it really needs a total rethink. Otherwise I strongly suspect you will be pulling the house apart to clear blockages on a regular basis, and unless you want half of what's gone down the WC all over you/the carpet whilst attempting to clear the pipework, I'd come up with a Plan B and fast.


Need a lot more info though to be able to offer an alternative solution.

 

[john-diy!]

Thanks for your replies, I have attached another photo to original post. The soil pipe cannot go externally from the new en-suite or we would have done that, hence the only route is internal. We did ask the plumber to check the existing pipework first for feasibility, before proceeding to fit the new en-suite. The building reg inspector arrived after he installed soil pipes & said it would not pass regs, we informed plumber, straight away, by that time he had completed about 20% installation, but he is continuing with project, & thinking about a solution, but it may require extensive building works, which he said he can't do. Where do we stand? Is there a more simple solution without knocking down internal walls etc. Should we ask him to stop working, ( he is at the tiling stage now). The bathroom installation company, subcontracted the work to the plumber, and they said they are seeking a solution.
What is a double branch? sorry I am not a plumber, & which part of the soil pipe would it go into?

 

[Harry Bloomfield]

sorry I am not a plumber, & which part of the soil pipe would it go into?

Not a plumber either, but my guess would be, that both pipes need to go separately, over that beam, into a vertical Y, at the other side.

 

[Hugh Jaleak]

Thanks for your replies, I have attached another photo to original post.

Thanks, that is helpful. I am assuming that is all going to be boxed in as part of the works, so aesthetics aren't a major concern. I think the only simple(ish) solution would be to use a Double Branch so both pipes connect on swept entries, and cap off the unused socket. Ideally both pipes need to join in the vertical section on the other side of the wall, but I would be concerned knocking another hole through could compromise the integrity of the wall.

Alternatively, a corner branch could be used, but there may not be room to dogleg the connection from above, across to suit.

 

[john-diy!]

Thanks, that is helpful. I am assuming that is all going to be boxed in as part of the works, so aesthetics aren't a major concern. I think the only simple(ish) solution would be to use a Double Branch so both pipes connect on swept entries, and cap off the unused socket. Ideally both pipes need to join in the vertical section on the other side of the wall, but I would be concerned knocking another hole through could compromise the integrity of the wall.

View attachment 401848


Alternatively, a corner branch could be used, but there may not be room to dogleg the connection from above, across to suit.
View attachment 401849

Thanks Hugh, yes I thought about knocking another hole above the same hole, in the wall too, to connect to soil stack, but I think it would need a structural engineer to assess the integrity of the wall. Alternatively perhaps a hole a meter or so earlier and on the other side of arch, you could feed it into the soil stack (on the other side of the lintel). It would mean lots of boxing in and opening up the soil stack, so aesthetically not great, but being practical & integrity is more important. Do you think its the responsibility of the plumber or/and the bathroom company who subcontracted to him to resolve this problem? They are supposed to be project managing it? Its so disappointing, because the en-suite its self, is looking amazing.
I really would appreciate some advice or reassurance at least that this can be resolved without too much disruption and at no extra cost, as we already have exceeded our budget.

 

[john-diy!]

Thanks Hugh, yes I thought about knocking another hole above the same hole, in the wall too, to connect to soil stack, but I think it would need a structural engineer to assess the integrity of the wall. Alternatively perhaps a hole a meter or so earlier and on the other side of arch, you could feed it into the soil stack (on the other side of the lintel). It would mean lots of boxing in and opening up the soil stack, so aesthetically not great, but being practical & integrity is more important. Do you think its the responsibility of the plumber or/and the bathroom company who subcontracted to him to resolve this problem? They are supposed to be project managing it? Its so disappointing, because the en-suite its self, is looking amazing.
I really would appreciate some advice or reassurance at least that this can be resolved without too much disruption and at no extra cost, as we already have exceeded our budget.

 

[denso13]

Do you think its the responsibility of the plumber or/and the bathroom company who subcontracted to him to resolve this problem?

Of course. They need to satisfy the inspector and building regs. What they have done is nowhere near correct.

 

[Harry Bloomfield]

Do you think its the responsibility of the plumber or/and the bathroom company who subcontracted to him to resolve this problem? They are supposed to be project managing it? Its so disappointing, because the en-suite its self, is looking amazing.

If they quoted you, and you are paying them to do a proper, workmanlike job, the end result should be a proper, workmanlike job. You can only suggest, what will and will not work, and what they have done will obviously not work - so is not acceptable.

 

[Hugh Jaleak]

Do you think its the responsibility of the plumber or/and the bathroom company who subcontracted to him to resolve this problem? They are supposed to be project managing it? Its so disappointing, because the en-suite its self, is looking amazing.
I really would appreciate some advice or reassurance at least that this can be resolved without too much disruption and at no extra cost, as we already have exceeded our budget.

If the company quoted for the work, then it is down to them to sort it out at no additional expense to you. The job should have been adequately surveyed and the quotation prepared from that information. I would expect a very good reason from their side to add additional costs if you haven't moved the goalposts!

Any Plumber worth the title, when asked to fit a WC in a new location, will first of all assess the possible route for the soil pipe/drain, as this is the deciding factor as to whether it can even be done! Macerators are an option is the Client is insistent, and no route can be found for a 4" soil pipe, but even then, there are limitations as to what the unit will cope with.

The route should have been planned, and the installer, if they didn't design it, should have been made aware of the planned route and method of connection to the existing stack/drain. What they have so far cobbled together is the work of amateurs, is of ridiculously poor quality, and goes completely against the laws of physics, never mind Building Regulations, little wonder the BCO has refused to sign it off!

They need to sort it out , at their expense. I would be very cautious about them knocking any further holes of the size required through that wall without a Structural Surveyor assessing it first. Unfortunately without being on site, it is difficult to offer any further suggestions about how to get around the issue, but I just hope the finish of your new En Suite isn't hiding all manner of bodges underneath. Have you actually managed to use it yet?