- Contains 3 updates (scroll down)
I tracked it down, yesterday morning just before I was meant to be leaving for work, to a pool of water on the kitchen windowsill that was dripping onto the floor. I mopped it up and tried vainly to find the source. None showed - nothing dripping from the ceiling (and for reasons I'll come to, I couldn't see how this would be possible anyway) so I assumed it was just a bad case of condensation on the window. A very bad case, but I'm an optimist. Then I went to work.
I came back at the end of the day and found the water had repooled. Now I looked more closely it seemed to be welling up through the window sill. Hmm. I've heard of rising damp, but we're on the third floor. Abingdon is not known for its supercharged artesian wells. The only other answer is that water was coming down between the wall and the wooden frame of the window. Down from ...
... Eyes raise slowly, reluctantly to the ceiling.
The ceiling itself still seemed unmarked and there's nothing above us except a very low, cramped attic space. The hatch is too small and the space is too limited to do anything with it, like store stuff. It's just there, cramped and cold and cobwebby. Even more reluctantly, I climbed up to have a look. It took a moment to work out what was going on.
A brief break for further explanation. There is one more flat above ours but it doesn't extend as far as we do. Their kitchen looks out over the roof above ours. The waste pipe from their sink and their washing machine goes through our roofspace. At one point, for a reason which truly baffles me, it turns a sharp 90 degrees, then another 90 degrees to resume its original direction. Then it goes out of the wall. Just after the first bend, it had broken. It hadn't come apart at the seams, the actual plastic had snapped, clean off. Everything that came out of that pipe now went straight into our roofspace.
And here is where we bless and offer up small sacrifices to the Gods of Victorian Plumbing. There's also an old cold water tank up there, probably from before the house was converted to flats. It's not part of anyone's system now and it's bone dry. Beneath it is a small lead-lined trough set into the floor of the attic. It's about 2m x 2m by 4cm deep, and was presumably to catch any overflow from the tank in days of yore. The broken pipe was pouring straight into this. Thus we hadn't had a deluge through our ceiling the moment the top flat ran their washing machine. We had to wait for it to gather enough water to overflow, probably when they did the washing up. No deluge, just a gentle trickle. Down the walls. Up through our windowsill.
So, we spent most of yesterday evening with me in the ceiling bailing out the trough, into a bucket which I would pass down the hatch to Best Beloved, who would pass it to Bonusbarn who would pour it down the toilet. The question of exactly what would snap a pipe like that was shelved for the duration of the immediate emergency. Once it was down to a manageable level we alerted our top neighbours (who are top neighbours in every sense). Forensic analysis was swift. Their pipe had blocked and they had called in Dynarod, the day before yesterday. We're not quite sure what Dynarod did but it involved a "heavy piece of equipment that went on the floor." Down a plastic pipe? They should surely have known better. Anyway, that's what dunnit.
Dynarod have been summoned back by Top Neighbours; any moment now I will be called upon to let them in, as repair work will have to be done in our attic. I await their comments with interest. Updates will be posted.
UPDATE 1: the plumber has arrived and has tried replacing the broken length of piping. Unfortunately we have established that the block is in one of the still intact lengths, and putting the megablockageblaster down it again will just result in a new rupture. Conclusion: next door also has a pipe running through the same space - this one being straight and with a nice fall. It's the waste pipe from one of their bathrooms (they have several ...) With permission of neighbour (since given), top neighbour's pipe will be tapped into next door neighbour's pipe.
UPDATE 2: pleasantly straightforward. It seems to work. All that needed doing after that was vacuuming out the standing trapped water - of which there was a lot more than I realised. Redoubled prayers of thanks for lead lining. The water was vacuumed out with a device a bit like an aquatic Henry, and of about the same capacity - so several emptyings were needed, after which the toilet looked like the family had had an attack of dysentry. Since restored to its normal gleaming freshness, and now back to work.
As I'd left my lunch at work, Top Neighbour kindly bought us a pizza from Domino's. Told you he was Top in every way.
We'll probably have to get a dehumidifier to dry the attic out again, but nothing structural has got wet.
UPDATE 3: Dynarod are delivering a dehumidifier tomorrow morning.
If you see any more updates it will be because something has leaked. Or possibly the duhumidifier blew a fuse and burnt the house down.