Shower / toilet pipework... help

[Madrab]

Have you inherited this? Or was this work done recently by a trade?

Unfortunately I do have to highlight that joist again too, I take it the bathroom is downstairs and that's a foundation void under a floating floor? Depending on the weight sitting on top of that, it's a potential longer term issue just brewing up too I'm afraid.

 

[Wayne_694]

Afraid I have to agree with Madrab here, that is a complete bodge, and to be honest, it's little wonder you're having problems.

The 110mm pipe needs to be on a minimum of 1:100 constant fall over it's length, ideally nearer 1:60-1:40, if its got any backfall on it, water and waste will sit in the pipe, cause it to sag even more, and just compound the issue. First thing you need to do is get that set correctly, (if you are going to struggle to get the levels set, then use a spirit level on top of the pipe, and make sure it is sloping the right way, all the way.)

Shower waste looks like it might be high enough to get it into the top of the 110mm pipe. Where does the other waste pipe come from? If its the basin, again you should have ample height to run it correctly into the top of the 110mm pipe.

Direct connection to the drain is perfectly fine for a ground floor WC, but given how this lot looks, I think we ought to see how they've made the connection into the manhole too please. (Might also be part of your issue....)

I would also ditch all that existing waste installation, and run it properly, using solvent weld waste.

thanks for your advice, so just a few points the main worry is the pipe has no vent and is is straight to the drain is this ok? and you're saying if I plumb the shower and basin into the top of the soil pipe it will be ok as long as the fall is 1:60 or 1:40? can you suggest what fitting to use? and would I just change the white boss fitting with a 90 deg elbow or is there another fitting you would advise?

 

[Wayne_694]

Have you inherited this? Or was this work done recently by a trade?

Unfortunately I do have to highlight that joist again too, I take it the bathroom is downstairs and that's a foundation void under a floating floor? Depending on the weight sitting on top of that, it's a potential longer term issue just brewing up too I'm afraid.

I have just moved into the house that has all just been done up, and yes you are correct how would you advise a fix? is this a big job and I should get someone in?

 

[Wayne_694]

Probably a daft question and I think we'll know the answer, but have Building Control been involved in any of this?

I have just moved int to the house, would building control be involved in a new bathroom been fitted?

 

[Hugh Jaleak]

Put a bend on the end of the run, so the WC is the last discharge into the pipe, and get the fall set right on that before you do anything else plumbing wise. (That joist needs sorting sooner rather than later too.)

Once you've got the soil pipe sorted, then couple the shower and basin in further along, as near to the top of the pipe as you can. Use solvent weld waste, done properly it'll never leak. If you haven't used it before, please ask for a guide on how to work with it, (it's not difficult but needs to be set up right first time, as you dont get a chance to alter it once the glue goes on!)

Yes, work would have been notifiable to Building Control, and then once completed, inspected and signed off, (if compliant, which this certainly isn't!). Have you bought the property? This should have been picked up on the survey!

 

[Madrab]

.... if it was a new additional bathroom or the old bathroom has been moved then it needs BC sign off, if it was just an update to existing then it possibly wouldn't need planning and if you didn't have a structural done.
I would suggest though that you could at least have recourse to go back to the lawyers and get them to contact the sellers at least about the drainage and structural concerns.

 

[Wayne_694]

Put a bend on the end of the run, so the WC is the last discharge into the pipe, and get the fall set right on that before you do anything else plumbing wise. (That joist needs sorting sooner rather than later too.)

Once you've got the soil pipe sorted, then couple the shower and basin in further along, as near to the top of the pipe as you can. Use solvent weld waste, done properly it'll never leak. If you haven't used it before, please ask for a guide on how to work with it, (it's not difficult but needs to be set up right first time, as you dont get a chance to alter it once the glue goes on!)

Yes, work would have been notifiable to Building Control, and then once completed, inspected and signed off, (if compliant, which this certainly isn't!). Have you bought the property? This should have been picked up on the survey!

Thanks for there advice, the survey was done through the mortgage company part of the deal for the joist how would you fix that?

 

[JimCrow]

The way you have the shower and basin into the 110mm pipe is fine and is not the cause of your problem and would work perfectly well normally, it also does not contravene the building regs.
Your main concern is exposing the bend at the other side of the wall and lowering it at least a couple of inches, do that and your problem will be solved, no need to alter the shower waste.
The joist at the shower trap can be reinforced will a steel plate.

 

[Madrab]

I have to disagree, that work just isn't right it shouldn't be left like that no matter whether it might work properly or not . It has been badly designed and can easily be done correctly. Whether it would have passed regs or not is immaterial, if it was a new run and a new bathroom, then it should have BC regardless. I can't believe it's always been like that.

The shower and basin waste will always be impacted when the toilet is flushed no matter adding extra fall, depending on how far into that branch the 40mm runs, the toilet could be flushing directly down onto the end of the waste pipe. I wonder if it's vented?

As far as the joist is concerned then it would need the trap moved and the joist repaired with a serious plate either side and bolted or a plug cut and it's glue'd and screwed in.

 

[Hugh Jaleak]

No, it's not right!

Looks to me suspiciously like they've used a rubber flexible drain adaptor to connect the wastes into the end of the 110mm pipework, given the socket of the Tee is actually pushed through the adaptor face says it all. Use of the correct part here would mean a compression socket and/or stub of 40mm pipe would be needed after the Tee to make the connection. If that 110mm pipe backs up and blows that drain adaptor back out, the result isn't going to be pretty...

If you're going to make a connection like that, at the minimum use of of these.

 

[Madrab]

Yup, looks like one of these in the end of it. If it is one of these then it just isn't right and I can guarantee BC would not have passed it.

Looking at the 2nd pic again I think I can see a screw which may be holding a wooden plate onto the back side of that joist so they may have at least tried to make up for that shocking notch cut into it.

 

[Wayne_694]

Thank for all your help much appreciated, I am about to replace all the pipework then I will fix the joist, moving the trap is not an option in my head as this is a lot of work. is there any other options? I will post more photos tomorrow once I have done my Christmas shopping.

Would this part be any good for connecting the waste pipes to the top of the soil pipe? 55722 and seen as I'm renewing the pipework where about would I fit this
913hr?

I got told to use solvent weld is that for both the soil pipe and the shower / basin pipework?

also their is no vent is that a problem?

last question... can you run a 40mm pipework through a joist?or do I have to go under the joist?

 

[Madrab]

If the chamber is vented/you have another bathroom that has a normal vented stack then you should be fine as long as the drop from this toilet isn't excessive.

The trick here is to get the fall on the run correct, use pipe supports or at worst galvy banding at this end of the run and support the pipe all the way down at each joist point, that way you can control the fall properly. Once you get that correct then as @Hugh Jaleak mentions, take that branch connector out, and replace with a bend and let the toilet discharge into that as the last on the run. A little further down the run you can then connect the shower/basin in, at least half way up the pipe. Use solvent weld waste pipe from the shower/basin all the way to the soil pipe connection. You can use the McAlpine expanding adapter or a strap boss to connect to the soil pipe.
Ideally they would have their own entry into the waste pipe but you could get away with teeing them together just before they enter the soil pipe. To minimise any interference with each other you would want to enlarge the pipe to 50mm at the tee and into the drain.

No ..... 32/40mm pipe is normally too large to notch or drill a joist within building spec, e.g. if a 46mm (40mm) pipe was to be run trough a joist, the joist would need to be at least 190mm deep, to put a notch in then it would need to be at least 370mm deep.

That's why I'm concerned about that notch for the trap. Measure the depth of that joist and divide that measurement by 8, that's the maximum that the notch should be, any more than that can compromise the strength of the joist.

The ARB 1 sits inside the pipe