Diagnosing a damp problem

[skiffler]

We have a damp patch on the kitchen wall, just under the window. I've been pretending it doesn't exist for a few weeks, but I think we need to do something about it.

Who's the best person to get some impartial advice on what's causing it and what can be done? I looked under damp-proofing in the Yellow Pages, but they all seem to be damp proof specialists - the kind of person I suspect will try and sell me a full damp proof course whether I need it or not.

Would a local builder be able to help?

I googled independent damp surveyor and the location to find someone. Ended up on a site which I now can't find but it was a directory-type site.

He was much more thorough than the two previous damp surveys we'd had done. He was also more expensive but the peace of mind of using someone independent outweighed that for us.

if you invite a salesman surveyor from a company that sells damp-proofing into your house, you can be pretty confident that he will tell you to buy his damp-proofing.

Is the wet patch inside or out?

Is there a pipe or tap near to it? Does it leak?

Do you get condenstation on the window due to poor ventilation, and does it run or drip down onto the wall?

Are there gaps around the windowframe, especially the top, that rain getys into?

What is the weather like when the damp patch is worst?

How old is your house? How thick is the wall? Are you in London, with the window-frame set into the inside part of the wall, and a sill outside; or is it set into the outside oart of the wall, with an interior window-board where you can place potplants and china figureines?

get a builer in to give an opinion. Could the window be leaking or is it coming up from the floor?

builder obv

Oh lord yes, steer clear of the damp course sellers! (learned that from experience)

I was about to ask the se questions as PJ but less succinctly. Damp doesn't appear for no reason, and damp proofing people will just change the fabric of your property instead of identifying the problem in the first place

Thanks for confirming my decision to avoid damp proof salesmen if possible!

It's an old Victorian house, wall is maybe a foot wide, window set into the outside of the wall. I keep cookery books on the window sill, and they're dry so I'm assuming there's no condensation or rain getting in - I've certainly not noticed it.

On the inside wall there are black mould spots (difficult to see as it's behind the kitchen drawers, but it seems to go down as far as I can see), and looking at the outside the stone is discoloured in the blocks under the window sill, but no lower, although it doesn't feel damp to the touch. Definitely worse in the wet weather with a noticeable smell of damp.

It's the wall on which the washing macine is placed, and the window sill looks a bit weather-discoloured. We've just sorted out a problem with the boiler, which involved the overflow pipe which is also on that wall, although a little further over from the problem.

it's in the kitchen, and close to the boiler and washing machine, so start by investigating the possibility of a plumbing leak.

usually, if you slacken the legs of a kitchen unit by winding them down, the unit can be pulled out. There may be a small number of screws attaching it to the units on either side, and/or the back wall, and/or the worktop.

When you pull out the kickplate to get at the legs you can sniff and use a torch to look for signs of drips on the floor behind the unit.

If not that, I would suspect gaps around the window frame. How old is it, and made of what?