Talking of which (solvent fittings), why do we use them? I discovered (by chance) that the main tank (or loft cistern) overflow piping had been knocked and dislodged a while ago. I repaired the joints. All the loints become brittle in time. Guttering and fascia boards have just been replaced on our property and one board obviously had to have the overflow jiggled about to be re-inserted through the fascia board, resulting in it being disconnected again (only because I thought about it afterwards - and it was). Wouldn't overflow pipes be better constructed of push fit or similar fittings that can't come apart? After all, when they overflow, people are often out and overflowing water is responsible for many house plumbing emergencies. Mark
Although overflow pipes can be pushed together with a tight fit, they should really be fitted with solvent glue, it's a bit more permanent then and won't come apart. Personally I prefer solvent waste fittings, wouldn't fit anything else especially under floorboards. Last thing you need is a worn rubber o ring that starts leaking as soon as it's disturbed
Push fit as overflow collapses with weight of water inside.. Many have no support and are useless come the day they are needed