Why was the job not signed off, was it not ready, or was it going to be signed off by somebody else?...Before the Job was signed off
If the AA mans says: "don't drive the car, until I'm back with the correct spanner to tighten the wheel nuts.", you can't really hold him responsible if you crash the car when you drive it anyway, can you?We asked if it was ok to turn the water on. He said it was, as long as someone was in the house. My brother turned it on and left the house for 8 hours.
A broken valve can hardly be blamed on the plumber.In this time, a valve broke and pushed out mains pressure.
If the walls were properly done, getting wet would not cause them to need replastering.The boiler is in the loft... All ceilings out (only floorboards remain), no carpets, all walls need re-skinning, not to mention water damage to the brickwork
As the house is being done up, it stands to reason that you needed new carpets anyway.
And water damage to brickwork????
Sounds to me like your damage estimate is about 10 times more than reality.