Newly plastered wall, now cold/wet marks

stuuyb

Hi,

We have recently had a lot of building work done at our property (going up into loft), and needed to move some pipework to make it work. Basically all the pipes go up, please see attached picture) and were chased into the wall (a fairly thin wall to be fair).

Plastered dried and all seemed ok until we noticed what appeared to be damp spots along the wall, following the line of some of the pipework. A, I right in assuming this is a leak?, moisture?, damp? They certainly weren’t there couple of weeks ago. It’s quite clear that they follow how the pipes are.

Pictures show wall area after plaster, all looks good. Then one couple of weeks later with what appears to be wet spots, it feels very cold to touch. Other picture shows how the pipework runs up through the wall (they were wrapped also I believe).

​Just after some of your thoughts? We will be getting the builders to come and look, and hopefully put our mind at rest and sort it (just don’t want to be fobbed off that’s all I spun a load of bull)

Thanks 

Steve

FreeBear

If one of those pipes is for cold water, you can expect a bit of condensation forming around it.

ThisIsWeird

The house hasn't been heated properly yet? The house is cool, perhaps a bit damp from drying plaster, and the water in the pipes much colder still - at least some of them, so a cold surface strip, susceptible to condensation forming, has to be a fair bet.
What is the connection between these pics? One shows 7 vertical pipe runs - is the damp showing on that wall? If so, in line which which of these pipes? And, what does that pipe deliver?
The plumber sensibly used continuous copper pipe lengths, so no joints behind the wall. However, it's possible that the push-fit connection at the top has been damaged - say the pipe wasn't deburred fully - and there is a wee swap travelling down the pipe.
At the mo', it's around a 50:50 chance of each cause! But, if the wall was fully dry after being skimmed, and then that - quite distinct - damp line formed afterwards, then I'm leaning towards 'leak'.
Can these plastic fittings be accessed relatively easily? 
Ah, I see that soldered joints were used lower down. Again, where is the damp line in relation to the whole stairwell wall?

stuuyb

Thank you for the responses.

the house has been heated properly for a few weeks now. One of the pictures was showing the wall after being plastered at the start of the month. The pictures with the wet/damp spots is the wall now, so I’m fairly confident the area was properly dry for sometime and the marks are new. The rest of the wall is fine, it’s just that specific area. It is distinctively cold and damp to touch, much more than any other area of the wall.

The wall they have been chased into is not a thick wall, single skin into another bedroom, which I guess doesn’t help, could it be that it’s not deep enough in? 

The 7 pipes run from below the stairs upwards feeding the upper level bathroom, boiler and cylinder (main boiler and cylinder is in the loft). The picture showing the pipes is prior to them being chased into the wall and plastered over. The area of damp is where the pipes are, from what I can make out best, it’s where the four pipes group are. My best guess is the mains pipe, TR or BC. I took a picture (attached) of the marked pipes.

the fittings won’t be easy to access, I’m guessing the plaster may need to come down and pipes checked. They were wrapped as well.

Stairs start from bottom left and rise from there. Damp line would be 

 

Red arrows are my guess as to where the damp spots/line are approximately, could be any of those 4 pipes, but most likely I would say one or both of the middle two

Thank you for your responses thus far

jonnydeppiwish!

See what it’s like after you’ve put at least a white wash and one coat of paint on it. Had my house replastered in the summer and they were similar marks but, once painted, never saw them again. 

Unlikely to be condensation as the plasterboard is unlikely to be in direct contact with the pipe, assuming it’s been fix with batons

ThisIsWeird

stuuyb said:

Thank you for the responses.

the house has been heated properly for a few weeks now. One of the pictures was showing the wall after being plastered at the start of the month. The pictures with the wet/damp spots is the wall now, so I’m fairly confident the area was properly dry for sometime and the marks are new. The rest of the wall is fine, it’s just that specific area. It is distinctively cold and damp to touch, much more than any other area of the wall.

The wall they have been chased into is not a thick wall, single skin into another bedroom, which I guess doesn’t help, could it be that it’s not deep enough in? 

The 7 pipes run from below the stairs upwards feeding the upper level bathroom, boiler and cylinder (main boiler and cylinder is in the loft). The picture showing the pipes is prior to them being chased into the wall and plastered over. The area of damp is where the pipes are, from what I can make out best, it’s where the four pipes group are. My best guess is the mains pipe, TR or BC. I took a picture (attached) of the marked pipes.

the fittings won’t be easy to access, I’m guessing the plaster may need to come down and pipes checked. They were wrapped as well.

Stairs start from bottom left and rise from there. Damp line would be 

 

Red arrows are my guess as to where the damp spots/line are approximately, could be any of those 4 pipes, but most likely I would say one or both of the middle two

Thank you for your responses thus far

Good info, thank you.
I don't know what some of these pipes are (not fully certain on any, actually), but suspect 'main' is the cold mains water supply. That would make it the coldest pipe, and if exposed to the air without lagging, you'd expect it to be running with moisture.
However, it is lagged, sealed away where it doesn't receive much fresh air, and is against 'warm' internal walls on both sides, so I'm going to suggest it isn't condensation (or else your plumber would have suffered the same issues countless times in other houses!).
So, that leaves a leak, and the likely candidate will obviously be that top plastic push-fit, which could be weeping very slightly, with a teeny dribble running down the pipe - the damp lagging touches the p'board at that point. 
Obvs just a guess.
Push-fits are very reliable, but great care needs to be taken when used with copper pipe - the pipe ends need to be smooth and rounded before insertion, or else it can tear the rubber O-ring.
As jdiw says, it may possibly just be dark plaster - you can get such variations after skimming - but I wouldn't expect such marks to appear afterwards.
Is there some way to determine whether it's actually 'damp'? Do you have a damp detector?! What happens if you press a tissue firmly against it for a few seconds? Or, you could lightly tape a sheet of clear plastic film - an old bag, or clingfilm, etc - around it, a good foot or two square, and tape around the edges. It doesn't have to be perfect, or sealed. Then observe - any droplets appearing on the back of the plastic, aligned with that stain, would indicate actual 'water'.
If still not clear whether it's actually damp, then a very light going-over with a sanding block and 180 grit should reveal it; if it's just 'dark-but-dry' plaster, it should go light pink like the rest, and  plaster dust should finely waft away. But, if the plaster is damp, then it'll clag your paper and remain dark pink.
If it's a leak, don't worry too much about the repair - it's quite easy to cut away a section of p'board, and make it good again.

stuuyb

Thanks for that.

im fairly certain the whole pipe was lagged, least a picture I had showed the bottom half lagged.
the builder was round today, has pencil drawn around the spots and will monitor over the next few days to see if it has increased or changed. He’s going to speak to the plumber anyhow around, mentioned maybe a pressure test of the system (I had previously increased the pressure slightly at the boiler as it had dropped a small amount, though seems to be stable now). He did also say as there is a void, filling with a lot more plaster it may take a lot longer to dry.., that I’m not so sure of but have no knowledge there so will go with what I’m told for now.

what I want to avoid is getting an issues months down the line

I was thinking similar, maybe a tiny amount leaking down, and leaning onto the plaster via the lagging.

i don’t have a damp detector but will try and get hold of one, makes sense for sure 👍 
I’ll also give you suggestion a go with plastic film, thank you

lets see what develops and I’ll update in due course.

appreciate you replying. 

FreeBear

stuuyb said: He’s going to speak to the plumber anyhow around, mentioned maybe a pressure test of the system

A pressure test should have been done before the pipes got covered over. But leaks, if they are going to occur, will be at the joints.

jcb208

My guess it is just staining, buy a cheap moisture meter and take some readings