Addition of new bathrooms - is this OK?

[STEVEROG]

Attached is a rough sketch of the pipework that has been added to my property to service two new bathrooms. WC1 was already in place, WC2 and WC3 are the toilets in each of the new bathrooms, one on the ground floor and one on the first floor.

Does this look ok? in particular, are there any limits on the distances "a" and "b" shown in my rough sketch? What about any limits on distances between the two toilets WC1 and WC2? Should there be any rodding points and if so where?

Note that the work has been left incomplete by builder who legged it so I thought I would check to see if I need to put anything right before I carry on.

Yes, I do have building control on board!

Thanks View media item 37072 View media item 37072 View media item 37072

 

[Richard C]

Is there a reason why there are 3 drawings, they all appear to be the same

27mm fall over 1.5m is the minimum but it’s a bit marginal; if you can get more, use 25mm per m (1:40) fall. If it’s a power shower, you may consider upping it to 50mm depending on the shower flow rate.

That wash basin connection should be
As long as the entries are not opposed (a risk of cross flow) distance B has no limit but you should stick to 200mm if you can; similarly with the wash basin stack connection

You could use a rest bend rather than a long radius but if it's already there.

Distance A has no limit. Neither is there any limit between W/C & W/C2.

You should have some form of access on the WC1/WC2 run, possibly from long radius bend or the existing bend where it dives into the drain invert. The requirement is it must be accessible for rodding from either one end or the other.

This may be of help:
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

You might also find the Hunter design guide useful which you can find on the Hunter waste web site.

 

[STEVEROG]

Thanks for the reply.

The three drawings....thats a balls-up!

I should be able to get the 200mm distance between wash basin and WC3. However, perhaps it may be better to feed the waste from WC3 in from behind the stack, the wash basin waste will then be at 90 degrees to it which is no longer "opposed" so is better?

I can definately get more fall on the shower waste so will do so

There is a rodding access cap on the end of the short bend at right of WC1 as it drops into the drain.

The long radius bend isnt fitted yet but building control said this was a requirement. I have just had a look for one on the hunter site but I couldn't find one in the above ground soil pipe fittings section. The existing bits that have been fitted are in grey 110mm plastic (solvent weld). I would like to run the rest in matching plastic if possible. Do you know where I can get an above ground grey colour long radius bend?

Thanks again for your input.


Steve

 

[Richard C]

The rodding access on the end of the WC1 run should be fine.

I’ve only ever fitted a rest bend at the bottom of the stack; I’ve never been asked to fit a long radius bend. If you’re having problems getting one, I would be inclined to go back to your LABC & ask why they won’t accept a rest bend. The only reason I can think is that you have another two W/C’s discharging directly into the horizontal drain run.

The colour of the pipe is not really relevant, are you not going to box it in?

 

[STEVEROG]

Richard,

They didn't say a rest bend couldn't be used, only in passing that the connection from the stack to the horizontal drain run should be a long radius bend. I believe the point they were trying to make was that the radius of the bend needs to be long, I think that the radius on a rest bend is the same as a long radius bend? If that's the case then either is ok. However, I am not sure that the bottom of a rest bend will reach the floor and still allow enough fall on the horizontal pipe, it could make the pipe fall the wrong way. I would then need to build a plinth to sit the rest bend on. I don't think I can use the orange plastic underground pipe above ground as I believe this isn't very UV stable. Perhaps I could use two 45 degree bends jointed with a short length of waste between them? Note that the all the pipe work is all on the exterior of the gable end wall on the side of my house, it won't be boxed in.

 

[Nige F]

So your " builder " left some of that lot on the outside wall of your house He didn`t consider putting a proper vertical SVP for WC`s 2+3 and shower/basin ..then doing some underground drainage to connect it all up . Is there a physical reason why this can`t be done

 

[Richard C]

Note that the all the pipe work is all on the exterior of the gable end wall on the side of my house, it won't be boxed in.

Ah, that explains it.

So your " builder " left some of that lot on the outside wall of your house He didn`t consider putting a proper vertical SVP for WC`s 2+3 and shower/basin ..then doing some underground drainage to connect it all up . Is there a physical reason why this can`t be done

I agree, I certainly wouldn’t be happy with that lot running olong outside of my house . If at all possible, I’d be looking to get it underground, even if it means relocating the stack; would involve a bit more work but a much better job.

 

[STEVEROG]

Gents,

First off, thanks for the input, much appreciated.

It's probably possible to run the vertical SVP inside the building either boxed in or buried in a stud wall that's going to be directly in line with the extisting position of the soil pipe. However, making the connection to the drain shown in the diagram by going under the house would mean major disruption undeath occupied rooms - not totally out of the question but I would rather not (the bathroom furthest to the right has a tiled floor I really dont want to rip up!

Perhaps a compromise would be to run just the vertical part of the pipework inside and have just the low level horizonal run. This would however mean having a long radius bend buried in the stud-wall with a short radius 90 degree bend on the end of the long radius bend as it goes through the exterior wall, this doesnt sound good to me.

I have had another look around and it turns out that the original bathroom waste ran to another drain that is to the left of the one shown in the diagram, its probably less than 12 inches to the right of WC2. Ouside the building I found a metal drain inspection cover with engineering brick and cement formed drain. There is a plastic pipe inside the building that connects somehow to a clay pipe inside this drain. I could run an internal soil vent pipe from upstairs, vertical on the inside wall then rest bend at the bottom below the room floor to turn horizonal and then another 90 degree bend and i am into the plastic pipe that connects to the brick drain. Note that this brick drain is connected to the newer plastic drain shown in the diagram. This was used for some time for the original toilet and still carries waste water from the kitchen to the newer plastic drain. However, this drain used to block up at least twice a year, the plumbers we called to sort it out always said that it was poorly designed/built as the clay pipe was/is a tight 90 degree turn and didn't allow toilet waste to exit well. I guess I would need to replace this drain with a new plastic one to do the job properly.

If I do all the above, with the soil pipe inside it would also then mean that the waste for the shower would be a pig to connect as the floor joists run towards the gable wall making it easy to get to the outside of the gable wall then turn to connect to the vertical stack but with things on the inside I would need to punch through the ceiling into the room below. The window in room below is pretty close to the ceiling leaving next to zero room to box in. The basin connection is also on the same side as the shower (yes my diagram is not correct) so this would be a pig as well as its a lot further away from the stud wall in the room below.

I'm starting to think that I may get a professional in to review my options before going off 'half cocked'.