Water pipes suddenly all sweating

Joined
7 Mar 2014
Messages
98
Reaction score
5
Location
Buckinghamshire
Country
United Kingdom
We've had building work (loft conversion) and as part of that had a new system boiler fitted back in July. The builder said we needed to upgrade our water main to get enough pressure. He dug a trench out and connected a new water main but did a temporary pipe through our wall into the kitchen. He said he would later finish the job by putting the mains pipe into the service void. Fast forward to just before Christmas and loft is pretty much done and water main wasn't. We were very worried about pipes freezing so they finally came and did it last week. This time he brought his son instead of the other experienced plumbers he used to fit the boiler. His son is a nice lad but very new to plumbing and has made a lot of basic mistakes in our loft and at our friends house where he is also doing work.

Once new main was put in the service void he filled the holes with some foam stuff. I asked if he insulated pipes as there were some in floor that were filled in with concrete and he said yes but I didn't see him do it. Anyway since that day we've had what we thought was a leak. He came and changed 2 elbows but now the wet pipes are out of control and looking online it sounds like they are sweating. These pipes are in our kitchen and we've never had this issue before. It's making our floor quite wet. What might be causing it and why all of a sudden? Could they have done something wrong, anything I should ask?
269787497_394527652448740_5336855232177209873_n.jpg
269795111_449200480083057_6041496314637448733_n.jpg


It's wet all along the small pipe at the bottom, all up the main pipe towards the stop cock and along the fatter pipe coming out.
 
Sponsored Links
Cold surfaces will condense water out of warm air.

Once insulated properly, the pipes will stop sweating.
 
So, are those pipes in the kitchen, or elsewhere? Do you have anything running slightly, eg a toilet cistern passing?
 
Sponsored Links
That's a nasty looking lash-up. And if that's the main cold water supply, those bits of 15mm aren't helping anyone- you've gone to the expense of chucking a new main (25mm, maybe bigger) and then put a metre of flow restrictor in. That bit looks very amateur- get them to come back and do it properly.
EDIT Wonder if the boy bothered with an insert in the MDPE?
EDIT 2 Condensation would form evenly, in droplets, all the way up the pipe. It won't form on those placcie elbows. Dry the pipe (kitchen towels, flannels, whatever) then see where the water is coming from. While the pipe is dry, breathe on it- see if you get any condensate
 
Last edited:
So, are those pipes in the kitchen, or elsewhere? Do you have anything running slightly, eg a toilet cistern passing?

The pipes are in our kitchen. The previous boiler was in a cupboard (which was ripped out to install new one) and some of those pipes are original and others new. The previous boiler (done before we had house) was a poor job and had used too many 15mm pipes everywhere and was all over the shop. The boiler install guys tidied it all up, moved boiler to corner and changed most pipes to 22. They expected the builders son to change final pipe to 22 when he did it too. However he said a 22 pipe wouldn't fit in void so he had to keep 15. He used the plastic fittings. Nothing running slightly as far as I can see. Also not had this issue until the boy did this water main bit.
 
  • Thanks
Reactions: CBW
Cold surfaces will condense water out of warm air.

Once insulated properly, the pipes will stop sweating.

I'd wondered that but none of the pipes were sweating when the new main was coming through the wall into the original area. It seems like more pipes are doing it now going further up. So many feel wet all along. We'd have to insulate most of them. Even the wall foam is wet.
 
I'd wondered that but none of the pipes were sweating when the new main was coming through the wall into the original area. It seems like more pipes are doing it now going further up. So many feel wet all along. We'd have to insulate most of them. Even the wall foam is wet.

Try this:

Dry the inlet pipe and the wrap it in a piece of kitchen roll and then wrap it in cling film. Leave for a day.

I'm wondering if you have a micro leak misting up the area

If the paper is wet, you have a leak.
If not, you may just have a damp environment?

Edit, and ask the builder to redo that inlet with proper fittings in 22mm

Looks horrendous.
 
Try this:

Dry the inlet pipe and the wrap it in a piece of kitchen roll and then wrap it in cling film. Leave for a day.

I'm wondering if you have a micro leak misting up the area

If the paper is wet, you have a leak.
If not, you may just have a damp environment?

Edit, and ask the builder to redo that inlet with proper fittings in 22mm

Looks horrendous.

Thank you will try this today. I asked about the 22cm inlet but he said it wasn't possible due to size of void? Also he has now filled everywhere with that foam!
 
I am also concerned the water main is not buried deep enough. They called someone they called mole man out to make the trench for the new blue plastic main. According to google the main should be about 2 ft down but I'm sure it wasn't anywhere like as deep as that. Not sure if this also impacts on our issues.
 
If it is not a leak, the pipes will be colder longer from a constant flow through them - you could try listening close to the pipe, when it is otherwise very quiet, maybe with a bit if steel rod/screwdriver etc.. Colder pipes will attract condensation.
 
@BlueLoo just removed the cling film and there is a line of wet on one side of the kitchen towel against the plastic elbow. Does this indicate the micro leak you mentioned? While that inlet pipe was sealed with clingfilm the other pipes still got very wet too after all previously being dried off.
 
Have a word with your builder. That excuse of 'not enough room for 22mm' seems a bit weak; after all, who made the void, and why didn't the continuous run of new (blue?) water main reach into the house where the first fitting on it would be its stopcock? Don't accept 15mm pipe when you've paid for (or agreed to pay for) an upgrade.
Treat the possibility of a leak seperately, and looking at the young lad's work it seems his standards are quite low.
 
Have a word with your builder. That excuse of 'not enough room for 22mm' seems a bit weak; after all, who made the void, and why didn't the continuous run of new (blue?) water main reach into the house where the first fitting on it would be its stopcock? Don't accept 15mm pipe when you've paid for (or agreed to pay for) an upgrade.
Treat the possibility of a leak seperately, and looking at the young lad's work it seems his standards are quite low.

Thank you. They have used the original service void from when our house was built (1960s). I did ask why he hadn't brought the blue one inside and connected but he said it wouldn't support the stop cock and needed to be a metal pipe? He also again said it wouldn't fit inside void. Can these voids not be made slightly bigger? Judging on his inexperience we aren't too pleased about him digging around near our house foundations either!! He has filled some of the outside with shingle.
 
First time posting but you should double check if you have any water leak ( overflow, boiler prv, outside tap) . More commonly if you have a push button toilet see if it's dribbling in the pan . If not Do you have a water meter ?
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top