Leaking drain gully

[trevorbayliss]

I have a rear gully which is leaking and I think is responsible for the damp on an internal spine wall.

I need to dig out the gully and want to move it to the right so it is a bit more away from that corner.

This house was converted into flats in 1965 so I think the drain set up was changed then. Originally there was a door into the cellar next to the old clay pipe.

Question: what coupling do I use to connect into the clay pipe. I want to connect when it is in the vertical position and then I will add backwards in plastic. I will probably do the last leg of the downpipe in plastic as well and angle it at 45 degrees to the right.

My other worry is, could the soil pipe wedged in the corner also connect into this gully and so use the large clay pipe? Or will that go all the way to the bottom and hit the floor with its own pipe?

 

[trevorbayliss]

anyone know the size of this clay pipe and what product i would use to adapt it to plastic. Ideally I would use an adapter which pushes into the clay pipe rather than the rubber adapters with clips.

 

[GoodDIYjob]

I only know the fernco type adaptors. I've used a couple in my time. Seem pretty robust. I guess eventually they will crack but they are used very widely.

You need to measure outside circumference like with a string or flexible tape measure, convert to diameter. Usually 120 to 130mm range.

Have you considered the gully is not your problem? Where is it leaking. How does the garden separation wall abutt the brickwork, looks like that would be a place of focus to me. Is damp visible in that area inside?

 

[trevorbayliss]

I can see the water coming out underneath when we put a hose in the gully. So def an issue with the gully or the pipe coming off it

There is no damp on that back wall. You have to go into the building and it’s the spine wall in the middle which is affected. It’s all just been tanked again as was done in 2008

I am a new owner of my top flat so doing some investigations and now found this rear drain is leaking. I can’t say this is the source of the issue but I must fix it first and then wait I suppose

 

[Madrab]

what coupling do I use to connect into the clay pipe

You get a couple -

Mcalpine do a finned one - It's a DC1
Polypipe do one too - UG459/486/487
The other mains soil/drain pipe specialist will have their own (OSMA etc)

The original bend will need to be cut out carefully, or cut below the bell end (ooer) but can't really see if that's another coupled end below it too?

I would presume the rainwater down pipe would use the same gully yes, you may have to repipe that somewhat too, to allow it to drain as well.

 

[trevorbayliss]

Thanks madrab

 

[GoodDIYjob]

I can see the water coming out underneath when we put a hose in the gully. So def an issue with the gully or the pipe coming off it

There is no damp on that back wall. You have to go into the building and it’s the spine wall in the middle which is affected. It’s all just been tanked again as was done in 2008

I am a new owner of my top flat so doing some investigations and now found this rear drain is leaking. I can’t say this is the source of the issue but I must fix it first and then wait I suppose

I only say this to try and help. Take it or leave it. Obviously, if the gully is leaking (looking at your photos I see some water at the base of the old basement door aperture - it should be repaired. But that is some void in there and the water will be dropping to the bottom of it. It has a long way to rise up to the habitable space above.

The reason I say that garden wall looks suspicious is because a) it doesn't look original, b) it looks to abut directly without a gap or mastic joint to original exterior brickwork and c) it is in the vicinity of where you think the problem is visibile on an internal load bearing wall. If it is abutting brickwork without separation it will create a substantial damp course bridge.

Unlike exterior walls, a garden wall is essentially open to elements at the top and has no roof over it...

 

[trevorbayliss]

Thanks for the info

The damp issue is away from this rear wall and on a wall in the middle of the house dividing the hall of this flat with the communal hall.

So water is rising from some part of this basement.

They filled it in when they converted the place in the 60’s. You can almost stand up in the room through that small opening, but the rest of the area under the floors you have to crouch more, but it’s still accessible. I’m only 5ft 8 so not the tallest.

So you think that back door wall is allowing water to track into the building?

It’s a possibility but the damp is popping up about 1.5m straight back into the building and then 1m on a right angle in the left direction.

The wall has been treated inside about 6 weeks ago and now further down that wall damp has popped out. So it is a bit of a mystery.

Looking down there we have now seen this gully leaking a lot into that gap area left to protect the clay drain pipe. So every time 2 flats above have a bath or use the sinks water comes into this area. Plus the roof water goes down here when raining.

 

[GoodDIYjob]

Thanks for the info

The damp issue is away from this rear wall and on a wall in the middle of the house dividing the hall of this flat with the communal hall.

So water is rising from some part of this basement.

They filled it in when they converted the place in the 60’s. You can almost stand up in the room through that small opening, but the rest of the area under the floors you have to crouch more, but it’s still accessible. I’m only 5ft 8 so not the tallest.

So you think that back door wall is allowing water to track into the building?

It’s a possibility but the damp is popping up about 1.5m straight back into the building and then 1m on a right angle in the left direction.

The wall has been treated inside about 6 weeks ago and now further down that wall damp has popped out. So it is a bit of a mystery.

Looking down there we have now seen this gully leaking a lot into that gap area left to protect the clay drain pipe. So every time 2 flats above have a bath or use the sinks water comes into this area. Plus the roof water goes down here when raining.

Ok. I see. So your damp problem, internally, is a long way from the gulley, downpipe and angled Garden Wall abutment? 1.5 metres is not so far....

If that's the case. Forget what I've said for moment.... unless of course some tanking is moving the problem along way from origin...

If the galleys leaking, I agree fix it. But there Is a lot of vertical height from where the water looks to be dropping.

I didn't realise that gully is serving bathrooms as well. I assumed incorrectly rainwater...

What is the basement void filled with? Building rubble???

 

[trevorbayliss]

Yes it looks like the tanking has now moved the damp along a bit. It has broken out on the end of the wall affected and this was treated further into the building about 3m long by 1m high.

The basement has loads of rubble and maybe old plaster. On the wall affected with the damp there is a slope of rubble rising up alongside it. You drop down it to get into this large room and the floor in here is smoothed out and solid almost, but it has been filled in as it is not the origional height.

You can see where previous damp guys have drilled into the bricks on this wall and done the damp proofing. The rubble is still quite a bit lower down. so maybe 60-70cm lower.

We can see all water pipes under there as well and no heating is leaking or cold feeds.

 

[GoodDIYjob]

Yes it looks like the tanking has now moved the damp along a bit. It has broken out on the end of the wall affected and this was treated further into the building about 3m long by 1m high.

The basement has loads of rubble and maybe old plaster. On the wall affected with the damp there is a slope of rubble rising up alongside it. You drop down it to get into this large room and the floor in here is smoothed out and solid almost, but it has been filled in as it is not the origional height.

You can see where previous damp guys have drilled into the bricks on this wall and done the damp proofing. The rubble is still quite a bit lower down. so maybe 60-70cm lower.

We can see all water pipes under there as well and no heating is leaking or cold feeds.

Yes, ok. Well your doing the right things as far as confirming likely culprits on drainage and water and heating pipes. And you've found one repair necessary.

If the rubble, or even worse (plaster debris) is wet, in the basement, it will or can hold water against walls. But 60cm below the injected damp proofing is a far bit of vertical height. And presumably the habitable room above where the problem is evident is higher still.....

Rising damp can spread but is usually curtailed by gravity to an extent, so there is usually a limit as to how high it can go. Often people talk about 1.5M in height but it can depend.

What you have to consider, per the other comments made about the tanking shifting the problem, is if is is entering a wall higher up than the basement, due to wall dpc bridging then spreading along the wall horizontally, because of the tanking and emerging somewhere else. moving horizintally is easier than gaining a lot of height vertically for water within brickwork.

Given the front of the basement area under the paving was once exposed and open, I wonder where the original DPC for the building was? How old was the property before conversion. Is there any sign of an original DPC in brickwork on those front elevations. It could of been down below basement door level on front of house!! Was any DPC injected on the front exposed walls of the house shown in the photos?

 

[trevorbayliss]

Its 1880 property roughly. Maybe a bit earlier.

I cant see any damp drill holes in front or back walls.

I am hoping to break into the gully area tomorrow and see if the toilet stack is somehow connected to this.

 

[GoodDIYjob]

Its 1880 property roughly. Maybe a bit earlier.

I cant see any damp drill holes in front or back walls.

I am hoping to break into the gully area tomorrow and see if the toilet stack is somehow connected to this.

Ok.

If you want more feedback a larger builder audience on the damp issue, tanking etc. You may want to ask mods to move the thread to the building section..

Or cease posting here and start another focusing on the building aspects once the drainage pipework and gully issues resolved.

 

[tell80]

You have a RWP that will need renewing - no historic paint down the back, and a gulley thats well accessible for testing.
You could cut below the second bend/hub on the vertical upstand but I dont know how these other pipes, & a new gulley location fit into the scheme of things - so be cautious with my suggestion?
You mention a WC soil pipe and another leak somewhere?

You also mention injection holes and tanking - thats an issue too far it seems eg its no good fixing new drainage if it going to obstruct your damp proofing possibilities?
You need a carefully worked out plan/schedule of work eg. removing all rubble & plaster from the basement
before anything else.
FWIW: injecting holes at low level in a basement is a waste of time.

 

[Nige F]

be cautious with my suggestion?

The truest thing you've written on Diynot ?