I am replacing my bathroom suite and shower and the waste pipes are 42mm OD. I have asked the usual suspects if this size is still available and have been told that their 40mm product has revolutionised the market etc. etc... Can you ell me if this size is currently available, it may not have been designed for this specific purpose, eg outdoor small bore drain pipes? I don't know. Any ideas?
Thanx for your time
Peter McMahon
I've been doing things with 40mm waste pipe recently.
Take a hot-air paintstripper, and rotate the end of the pipe so as to heat the end 20mm or so. Take a greased cloth, and now squeeze down the end so that it's a little narrower in diameter. (you want it slightly floppy, but not so much that it will distort under its own weight.)
Chamfer the ends so that it provides an extra bit of taper. Now, allow to cool, and oil (sunflower oil works fine).
Heat another bit of pipe, around 50mm, warm it a bit, and now press the oiled pipe into the pipe to be flared. Now, when cool, remove.
This flares the pipe so that another pipe can fit inside it easily, with a nice tight fit. (10Kg or so force needed to push in) A smear of silicone sealant first makes a nice lubricant, and makes the joint even tighter when set.
Measuring the outside of the pipe, I will note that "40mm" pipe from focus (1.60 or so per 2m) is 41.2mm.
40mm plastic (1 and a half inch) internal diameter is the normal size for wash basins, baths and kitchen sink installations. The three most common sizes today are 32mm, 40mm and 50mm, one and a quarter inch, one and a half inch and two inch respectively. You may find a slight difference between the manufacturers fittings and pipes though, so try to keep all the plastic plumbing from the same makers to stop you having problems with outer diameter sizes not being able to fit inside a different makers fitting. It's all to do with pipe wall thickness.
You'll find 2 sizes and different types of plastic in nominally '40 mm' (aka
1.5") waste pipe: a slightly larger diameter in ABS pipe which is for solvent-welding to appropriate fittings, and a slightly smaller diameter in Polypropylene pipe (marked 'PP') for push-fit couplings. You _can_ just about get solvent weld pipe into a push-fit fitting (chamfer the end and grease it well) but can't join push-fit pipe into a solvent-weld fitting. The proper way to join the two if you have to do so is with compression fittings (which fit both sizes) or solvent-weld couplers with a push-fit socket end (rather misleadingly labelled 'expansion couplers' in B&Q IIRC).HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.