PigletJohn, can I ask you about a leakage we have?

[jalopy]

Our outside wall is damp (side of the house) and we are unable to work out the cause.

Our roof tiles are intact and the guttering is fine. At irregular times there is extensive areas of damp down the full length of the wall (approx. 15 feet x 6ft across) and it is evident on the ground as well, although dries up as the day goes on. This is happening even in dry spells of weather. We never see any dripping anywhere so not sure if this is happening at night.

A while ago we had problems with our external overflow pipe situated at loft level. The overflow valve kept getting stuck in our cold water tank in the loft extension. This was replaced and since then we haven't witnessed any overflow problems. We have checked the level of the water in the tank and it seems ok.

We have looked around the very confined loft space and cant find any evidence of a leaking pipe that might be causing the wall to be so damp. The problem seems to have escalated over the past few weeks and now the dampness is penetrating the plaster inside the house.

Can you think of any other source of water that might be causing the leakage? Is it possible that the other pipes connected to the water tank could be the problem? We are stumped and rather reluctant to call upon a plumber until we have a clear idea of what is going on.

Hope this makes sense.

Many thanks. x

If it is happening at night, then you might have a dripping ballcock that is overfilling a tank. During the day you will be running the taps and flushing WCs so using the water before it starts to overflow. Go up there early in the morning before using any water and look at the levels in the tanks.

Turn off the boiler the night before. Stay up there while someone turns the boiler on and see if there is any gurgling or splashing

If still looking, turn off the watermain in the evening. The next morning, before using any water, look in all tanks and cisterns to see if the level has dropped.

Get a ladder and look in the gutters to see if they are full of leaves, have leaky joints, are rusted at the back, or are holding water due to lack of slope.

Do you get condensation on the windows?

Thanks PigletJohn.

We will do the checks in stages, as you suggest. We'll start with checking the overflow status over the next couple of nights.

If that sheds no light, we'll turn off the mains to check for leaks. If none the wiser, we'll turn off boiler, as you recommended.

Yes, we have been getting condensation on windows but only since this problem arose. It's difficult to ventilate the worst affected room since it so cold at the moment.

Thanks for replying. x

Sorry to hijack but PigletJohn, do you know anything about cellars?

I think Piglet John knows everything.

not much

they are usually damp, and need lots of ventilation.