Worrying amount of condensation on cold water pipes

[tinyrick]

We moved into a pre-1900 terrace a couple of years ago and found the kitchen to be sodden. We ripped the units out, let the walls dry and had a damp proof course installed. We left it for a couple of weeks to make sure the walls were dry and all joints in the water pipes were sound before we installed the new units and decorated.

A certain part of the wall where the pipes go into the plaster and upstairs to feed the bathroom started producing salts after a few months and the paint peeled slightly but we thought maybe this was because we painted it too soon, and as we were busy fixing all the other hidden faults in the house and having a baby, we didn't investigate further.

Recently we've noticed a damp smell downstairs and some boxes in the cupboards had become mouldy so I thought I had better take a look.

I took the kickboards off and looked underneath the units with a torch and the walls behind were absolutely drenched in two corners. There was a visible layer of water on the plaster. I called the guy in who installed the dampproof course thinking the moisture was coming up from the ground, but he said it looked like condensation caused by a leaking stopcock that happened to be dripping wet at the time (but isn't usually). The work was guaranteed and he said he'd come back in a couple of weeks to take the units out and investigate the cause.

He couldn't come any sooner so I decided this weekend to take one of the units out and take a look myself. This is the sink unit that's positioned in the corner of the room and has the water supply pipe coming out of the concrete floor beneath it, with the stopcock coming up into the cupboard and then out and around the walls to feed the taps, boiler etc. The lower part of the wall was soaking but didn't appear to be too bad at ground level. After a few hours of drying the plaster out with a hairdryer, I left it to see where the moisture would come from. Everything stayed dry so I ran the boiler and upstairs taps to get the water flowing in the pipes. The cold water pipes and stopcock became moist almost instantly, with an even bead of sweat on all exposed pipe that wasn't plastered over, with the exception of a small section in the bathroom that's glossed over and a section behind the bathroom sink that's nice and shiny and new looking. The rest of the copper piping is badly oxidised and green and I have no idea how old it is.

After trawling the forums, it's evident that some amount of condensation is inevitable in a house this old but the pipes are getting so wet the plaster is not drying out and the damp just builds up in the walls. Is there anything I can do to prevent the pipes getting so wet?

 

[Agile]

This is a typical result of installing pipes in plaster without knowing that they need insulating.

Also your lifestyle clearly involves producing vast quantities of moisture without any proper ventilation.

You probably boil your cooking without realising that it never goes above 100°C however much heat you put in it.

Start by reviewing your ventilation and having some. Then cook most veg in butter for just a 3-4 minutes. Potatoes cook nicely in the microwave and then finish off in water for just a few minutes with a lid on the saucepan and the gas turned down to minimum.

And I hope you dont BOIL nappies?

Any water vapour you produce goes nowhere except onto cold surfaces.

In the kitchen here, although its not even double glazed, there is NEVER any condensation on the window. As soon as any cooking starts, the extract fan goes on. Result a clean dry kitchen!

Tony

 

[oilman]

An injected DPC is always a waste of money. Draught proofing is also a waste of money. When all the draughts have gone, you have to fit ventilators. In the words of the great politician, "Ventilate, ventilate,ventilate".