ive had normal setting times in winter when everythings been fine but then had a fresh delivery of multi, stuck a normal amount on, waited, waited some more, thought sod it and chucked a few more walls on, still waiting for the first lot, another wall on...
then topped the whole lot in one go...
1 set lasted all bleeding day! (all on new plasterboard btw)
it was cold though, not minus temperatures but chilly cold, its just that the first batch was fine its only when i got some more plaster in that this happened... right at the end of the job too...
maybe theres a cut off point in the chemical make up where its fine right up to that point but 1 degree under it and completely changes its behaviour?
breaking ice in a barrel to get water makes a difference too...
its been said before that bg reps have told people that bg alter the amount of retarder in the plaster according to the time of year...
whether thats just the reps gob working overtime or not is a mystery but ive definately had different setting times on different batches... none out of date either...
ive also had stuff go off lighning quick with no explanation... all suction sorted... ive blamed everything from shite pva to heating pipes running across ceilings but it happens all the same..