Hunting the damp

[blufive]

We've had a persistent damp problem at the back of our kitchen for ages. I thought I'd sorted it last year when I patched a hole in the drainage arrangements for the flat roof, re-applied sealant to the window, and fixed the dishwasher outlet so it doesn't backup and pur water all over the floor.

The plaster slowly dried out - until it left one small patch, which didn't go away. So we have yet another source. This patch doesn't change with the weather, like the rest used to, so I don't think it's an external leak.

After much thought, I theorised that the water pipes, which vanish behind cupboards in that corner before diving under the floor, must have a leak. Unfortunately, since we have fitted cupboards, a thorough inspection of those pipes would mean totally destroying that end of the kitchen to get to them.

This weekend, I removed the floor-level panels on the cupboards, so I could see the floor under them. This revealed signs of damp in the expected area. So I triangulated from the signs of damp, and the nearest visible location of the pipes, to work out where I reckoned the problem was.

I then had lots of fun cutting a hole in the far back end of a fitted kitchen corner cupboard to get at the wall/pipes behind. Mostly by hand, since there wasn't enough room in there to wield power tools. Well that's my workout for the day.

Having cut through: no pipes. Drat. Missed by a couple of inches, but at least I now have a hole in about the right place to look through. Cal was amused to find me sat, half in the cupboard, poking our digital camera through the hole to take pictures of what's in there.

The water pipes are a bit damp to the touch, but I think that's just condensation, and it doesn't look enough to make the plaster wet 3 feet higher up the wall.

We also have a mysterious extra pipe, half-buried in the external wall. On the inside, it's just an open end, there's no sign of it on the outside, and it feels bone dry. So I don't think that's it, either.

So where's the damn damp coming from?