Last time I turned off the mains water, the neighbours were shocked. Today I went to them all and warned them. I promised no more than 30 minutes' outage. I already had the compression fitting cap end to stick on the end of the pipe. What could go wrong? Well, I wasn't feeling too cocky.
I turned off the water, cut the pipe high up and drained it into a bucket. A little seepage onto the floor, but largely successful. Then I cut it where I was going to cap it, capped it, and then went downstairs to try putting the water back on. Essentially, I was turning a tap which would allow a bunch of water back into my pipes. These pipes also contain some air and there is no tap to let this air out through (since the pipe is now totally capped). In one single turn of the mains stop tap outside, I was allowing a water pressure, possibly pushing against an air cushion, to build behind my two capped ends (one from today and one from Saturday). This, to me, seemed like something which could cause a cap to decide to come off.
I ran upstairs to look for signs of problems. The sign would be something like sweating, dripping or gushing. There was nothing. I'd done it. 5 minutes and job done.
I still had a cistern full of water and a toilet which apparently wasn't connected properly to the soil pipe. I also had some water in the bottom of the toilet.
It was time to try to drain the cistern. I had three buckets on standby. I also found that the cistern pipe didn't seem to be fully connected to the toilet. In fact it was loose. Perhaps it was the cistern pipe that was gushing the other day, rather than the waste. Overall, I think that would have been the best thing to happen, since the waste would contain, well, waste.
I held the open end of the cistern pipe over my bucket and flushed. The water came. The bucket filled. I swapped buckets. There was some spillage. The water stopped lng before the second bucket filled.
This was great.
I set about removing the cistern from the wall - it was tough, but I managed it without slopping the water, left in the bottom of it, anywhere it shouldn't have gone. I pried the toilet off the floor and emptied its remaining water into a bucket.
Essentially, I didn't mess this up. I now have no bathroom fittings at all fitted in my bathroom and today I sent a cheque, along with detailed instructions, to the guy who's going to fit new stuff. All I have to do is clear some rubble sacks, do a few more passes at sweeping the room out and cut the cast-iron bath up some more, so I can remove that. Sounds pretty doable.