What is this pipe?

scottishblondie

This pipe is boxed in in the bathroom of a flat. We exposed it due to some ongoing damp issues, but we’ve no idea what it is. The factors (building management) sent someone to investigate but their “report” hasn’t left me any the wiser. They’ve deemed the pipe as private, so now we’ll have to fix whatever the issue is ourselves.  The flat has a combi boiler for heat and water.  The pipe comes up from the floor and stops at about 4 feet up. Can anyone explain to me what the purpose of this might be?

(Sorry for the weird rotation of the photos, not sure how to fix)

scottishblondie

This is the report from the plumber they sent out:

”I gained access to the above property and checked all visible pipe work in the bathroom and found ok. I removed the plastic cover on the pipe chase and found what looked like steam rising up and could also hear the sound of a possible burst pipe.

I isolated the hot water supply at the combi boiler and it sounded like the noise had stopped and the steam had reduced, so I turned the hot water on and off several times and found the same outcome, therefore I can confirm that there is a burst on the hot water supply. Hot water has been left isolated.

Job is now a private repair.”

Ajmason42

Grey pipe like That looks highly likely to be soil pipe   pic 2 the "T"  probably where the toilet connect 

 the hot water supply likely to 15mm copper.  Find a good local plumber to come out  any water damage may be covered by your insur6subject to excess  

scottishblondie

There is nothing attached to the pipe above floor level. The toilet is on the other side of the room. I will attach a diagram of the room shortly. 

payless

The report implies  the leak does not relates to this waste pipe , rather on a hot water supply.. do you have any other isolation-points on HW supply to try and figure our where the leak is, otherwise plumber or insurance ( trace and access cover needed ) the excess may be as much as the plumber. ( although if claiming for damage it is usually a single excess) Is plumbing in sight or in walls / floors , sometimes easier to just reroute 

scottishblondie

Here is a rough diagram of the bathroom.  It is a ground/basement flat built circa 2001.  This bathroom is on the basement level, and there isn't actually any part of our property above it - the porch and front door to the building is above where the is toilet, and the bottom of the "L" has the common close area leading to the stairwell above.  The entrance to our property is roughly above the door in to the bathroom.

EDIT: for a bit more context, I used to live here but this flat is now rented out.  The tenants first reported some damp back in March, but after I asked them to try a dehumidifier and keeping the ventilation fan on (as they had been keeping it turned off) I didn't hear any more about it until a couple of weeks ago.  The damage is now pretty extensive, unfortunately.  I will be employing a plumber to come out ASAP, but I want to understand what this is all about.

scottishblondie

payless said:

The report implies  the leak does not relates to this waste pipe , rather on a hot water supply.. do you have any other isolation-points on HW supply to try and figure our where the leak is, otherwise plumber or insurance ( trace and access cover needed ) the excess may be as much as the plumber. ( although if claiming for damage it is usually a single excess) Is plumbing in sight or in walls / floors , sometimes easier to just reroute 

The only isolation points I'm aware of are directly at the boiler and on the taps in the kitchen, toilet and bathroom.
EDIT: Sorry I missed the last point - all the plumbing is hidden away.  I don't even know what there is underneath the floor - it is chipboard not concrete, but I'm not sure how much space there is below.

grumbler

scottishblondie said:

This pipe is boxed in in the bathroom of a flat. We exposed it due to some ongoing damp issues, but we’ve no idea what it is. ... The pipe comes up from the floor and stops at about 4 feet up. Can anyone explain to me what the purpose of this might be?

Looks like a soil pipe with some sort of air admission valve at the top.

Jeepers_Creepers

Two issues - one is the burst pipe and resulting damp. This is surely an insurance job? And you surely have insurance...?

I don't know how extensive the damage is so cannot speculate on the repair cost, but if this leak has been occurring for more than half a year, then it's surely 'deep'? 

The other issue is that 'soil' pipe. Nothing goes in to it at any point? And the top of the pipe is fully open? When you stick yer nose above the open end, is there any smell? That 'tee' further down (second pic) - is the side branch open? And how far is that side branch from floor level?

Most likely it's a soil/vent pipe to serve either a previously positioned toilet in that bathroom, or else used to serve a flat above. But that's pure guesswork. If it doesn't smell or create a draught, then I don't see it's causing any harm. (I'd still love to know what it's for, tho'!)

scottishblondie

grumbler said:

scottishblondie said:

This pipe is boxed in in the bathroom of a flat. We exposed it due to some ongoing damp issues, but we’ve no idea what it is. ... The pipe comes up from the floor and stops at about 4 feet up. Can anyone explain to me what the purpose of this might be?

Looks like a soil pipe with some sort of air admission valve at the top.

Looking at images of air admittance valves for soil pipes, I'm starting to think that is what it is.  

scottishblondie

Jeepers_Creepers said:

Two issues - one is the burst pipe and resulting damp. This is surely an insurance job? And you surely have insurance...?

I don't know how extensive the damage is so cannot speculate on the repair cost, but if this leak has been occurring for more than half a year, then it's surely 'deep'? 

The other issue is that 'soil' pipe. Nothing goes in to it at any point? And the top of the pipe is fully open? When you stick yer nose above the open end, is there any smell? That 'tee' further down (second pic) - is the side branch open? And how far is that side branch from floor level?

Most likely it's a soil/vent pipe to serve either a previously positioned toilet in that bathroom, or else used to serve a flat above. But that's pure guesswork. If it doesn't smell or create a draught, then I don't see it's causing any harm. (I'd still love to know what it's for, tho'!)

There is a common buildings insurance policy.  I have no idea if this would be covered or not, I will need to ask the factor to provide the full policy details.  The leak would have to have been ongoing since February or March, and the floor of the bathroom is now "spongy", so it is possible the whole thing will need to be refitted.  I'm not overly concerned about the cost at this point, I just want it resolved ASAP.

The "soil" pipe doesn't have anything going in to it.  There is a cap/valve thing on the top, as grumbler suggested above I now think it could be an air admittance valve for the soil pipe.  The tee is not open, and is sitting just above skirting board level.  There has definitely never been a toilet there - we are the 2nd owners and there was no change in layout from new build.  There is no flat above here, it's the common close leading to the stairs. The next flat above us is 2 floors up from this bathroom, and pipe aligns roughly with the middle of the dining area in their kitchen.

I'm starting to think the pipe itself may be a red herring.  If there is a leak under the floorboards, then the area around the pipe may just have been an easy route for it to come up.  The moisture could have soaked up the plasterboard behind the tiles to ceiling level, and then crept out into the plasterboard on the ceiling where it was finally visible.  The dampness appeared at ceiling level and then migrated down the plasterboard wall next to the duct towards the floor, which had us convinced it was coming from some common source in behind the wall.