Thanks for the pic smtplumbing. I've seen plenty of those fittings in the merchants but had hoped to get a solid plastic fitting like the one that is installed already. Either way, I'd have to cut a piece out of the pipe and also use a slip coupling. Apparently, the stack was installed by the council but, as far as I'm aware, the tenants now own the property but they can't afford to have the whole stack removed in order to replace the leaking joint. To be honest, the jobs a pain in the a**e and, after more than a year of not hearing anything from the customer, I'd assumed they'd got someone else to do it. I'm inclined to think that everybody else was suddenly very busy after they'd seen the job.