I'm plumbing a new barn conversion, bathroom, kitchen, cloakroom & utility. The different plastic waste pipes are driving me to depair. Got a new shower tray fitted with a trap and waste pipe, the pipe was a very small diameter, but it's been impossible to find a straight connector to match the thread on the trap. B&Q sell one for £15 with a long corrugated pipe but the thread is JUST the wrong diameter. First snarl.. Second snarl, for the utiity and kitchen I've run the 'main pipe' to the drain in solvent weld 40mm pipe. The traps are 32mm compression Ne'er the twain shall meet... Is there any way to easily convert from solvent to compression? Of course compression pipes are just a slightly different diameter to solvent pipes.. Why? Just to make life REALLY difficult!!!! Any help please, before I throw myself off the roof!