shower waste to washing machine waste

[Mike S]

I'm trying to set up the waste pipes for my washing machine which I've moved and a new shower. I wonder whether anyone could comment on the following proposal:

I plan to run a 40mm waste pipe for a washing machine for about 2m along an inside wall on the ground floor. It will then run for about 2m along the outside before emptying into the main drain - all the wastes in this rather old property empty above ground and exposed to the elements into the main drain in this way (apart from the soil stack which enters the same drain but below ground). The total run will have four 90 degree elbows in it - 3 inside and one on the outside.

I would also like to T in the shower waste to the washing machine waste on the inside, again using 40 mm. The distance from the shower trap to the washing machine waste will be less than a metre.

Does this sound OK? I know there are guidines about achieving a minimum drop along the length of the waste - are there any about achieving a maximum drop? I don't want waste from the washing machine rushing down and swamping the shower.

Any comments or suggestions would be very welcome.

Thanks,

Mike

 

[Hugh Jaleak]

Assuming shower and washing machine are going to be on the same level, I'd upgrade to 50mm pipe where the shower waste joins in, otherwise there may be a risk of the washing machine water popping up in the shower...

Use swept bends rather than elbows, allows better flow through the pipes, and if using solvent weld i'd fit a rodding eye or 2 in lieu of bends in case of future problems.

 

[grahamtheplumber]

you could add a HepvO trap on the shower.
http://www.hepworth.wavin.com/maste...m_detail_I&FOLDER<>folder_id=2534374305508362

 

[moggridgeplumbing]

Agree with Hugh. You may get away with the layout at first with 40mm but washing machines do pump out a load of crud, which can build up in the pipes, so have at least a 1 in 40 fall on the pipes and up size to 50mm if possible, with rodding tees, after the shower joint.

 

[Mike S]

Thanks for the advice guys. All makes sense. Everything downstream from, and including, the point where the washing machine and shower outlet pipes meet should be accessible for cleaning... am I right in saying that that is the key issue here?

you could add a HepvO trap on the shower.
http://www.hepworth.wavin.com/maste..._I&FOLDER<>folder_id=2534374305508362[/QUOTE]

What does this do though?

Mike

 

[Hugh Jaleak]

The HepVo valve can be used in lieu of a trap, it also acts as a non return valve. However wastes can clog with soap, hair and fibres from laundry, even with a Hep valve there may be a problem in the future with slow draining. The shower will back up into the tray, but the washing machine will just carry on draining, what doesn't go down the pipe will erupt onto the floor

It depends which type of pipe you want to use, compression or push fit systems can be dismantled for cleaning should the need arise. Solvent weld (the professionals choice and looks far neater) cannot be dismantled! If it blocks and you cant get a snake round a bend to get to the blockage then taking a hacksaw to it is the only answer!

 

[Mike S]

Thanks Hugh, I think I'll stick with the conventional trap and take my chances. I've managed to identify a route that will involve less twists and turns now, so the shower and washing machine will now meet at compression T which I can dismantle and clean if necessary. Downstream of the T there will be just one elbow or bend on the outside wall which will also be a compression, and therefore serviceable too. There will be a couple of bends (not elbows) upstream of the T on the way to the washing machine. These will be solvent welds. One of these won't be accessible at all without removing the shower tray, but the other will as it will come out through a wooden panel and directly into the washing machine trap attached to the outside of the panel.

I'm hoping this will work!