Waste Plumbing, washing machine to 50mm waste pipe?

[Hugh Jaleak]

Also doesn't the top of standpipe to bottom of washing machine need to be a minimum height and the standpipe a certain length.

No, drain hose has to rise to at least the height of the machine to prevent it siphoning the water out during the wash cycle, some machines have a label with a line to mark the minimum height of the drain hose.

For the OP, some good advice there from Denso, you need to tee into the 50mm and fit a trap of some description, or you'll have odour issues before long. That is a hell of a run, even in 50mm, it's a lot longer than Regs permit, and after a while when its gunged up with soap/hair/fibres/muck, it's gong to pong. You really dont want that coming back into the room, hence why you need a trap.

Ideally you should really have brought a underground drain run into the building, and connected the waste into that at floor level.

 

[Sonic70]

Hugh I may of been thinking of requirements in usa that I read up on ages ago.

Victor

 

[Mike13]

The outside wall that the sink is against would have needed over 30 metres of external drain around the outside of the house, and there was not enough fall available to do that. Or run a drain under the house somehow, and that brings other problems. It seemed easiest to run round the room, there was a doorway preventing a shorter route from being used. It was an extension converting a conservatory into usable space. The idea of moving the sink came too late to have it planned in and an internal drain drawn in and budgeted for.