More bathroom woes

We've had a damp patch in the kitchen for quite a few weeks, directly above the boiler. Nikki noticed it first, where the plaster was bubbling above the kitchen window, but after a few days a larger damp patch appeared in the corner and slowly grew.

We entertained a few theories regarding its origin. On the outside wall in the same position is the hopper that takes waste feeds from the shower, basin and bath, so our first guess was that this had become blocked and was overflowing onto the wall. At the first opportunity (i.e. when the rain had stopped) I deployed my trusty ladder and went up to take a look.

It was as clean as a whistle, but while I was up there I noticed the pointing was in pretty bad shape. As we'd had some heavy rain, maybe it was a case of penetrating damp? That was my theory, although Nikki continued to believe the hopper was at fault. If it wasn't blocked, maybe it just couldn't cope with the volume of water? Tests were inconclusive, but we decided to call a builder in. We needed a quote for bricking up the kitchen door anyway.

Said builder duly attended and, while he agreed the pointing needed attention, he spotted a more likely candidate. An old vent hole that had not been sealed properly. What's more it matched the location and shape of the worst area of damp. Problem sorted, we thought.

That was until my traditional 2am loo break last night. With the house in silence an eerie tick... tick... tick... could be heard from the general direction of the bath. Now this isn't unusual in our bathroom, as the sash windows drip loudly onto the sills when it's raining. But this particular night, it wasn't raining. First thing this morning saw me with my belly pressed against the cold tiles, peering under the bath. One glance was enough. The puddle stretched for a couple of square feet and a slow but regular drip emanated from the cold tap supply pipe. I fetched a bowl.

The bath stands on feet on a tiled floor. It moves. I assume the occasional movement (when we nudge into it, or dry feet on it after a shower) has sprung a joint in the pipework. As if we haven't had enough trouble with this £$%&* bathroom!