washing machine outlet into soil pipe ?

[kdband]

We're having the kitchen done soon and we'll be moving the washing machine into the utility room. Actually, it's a downstairs loo/cloakroom/boiler room which we've knocked through into one single room. We are planning on moving the loo and partitioning it off. The plan is to use the existing connection to the soil stack and just extend the soil pipe inside the house. I'll also need to install a waste pipe for the washing machine. I'd rather not have to drill another hole through the wall as it's over 2 foot thick. Is there any reason why I can't tap this into the top of the soil pipe? If It's OK, then what should I be using, is there a specific boss for this? Obviously I'll need to install some kind of trap to prevent smells coming back up but do I need a non-syphon trap or just a standard U bend? Does it matter what size waste pipe I use (32mm or 40mm)? Finally how long should the vertical pipe be for the washing machine tube?

Thanks.

[Roger Mills]

You need one of these:

?_dyncharset=UTF-8&fh_search=49547&searchbutton.x=10&searchbutton.y=8&searchbutton=submitand one of these: ?_dyncharset=UTF-8&fh_search=18640&searchbutton.x=14&searchbutton.y=10&searchbutton=submitplus a short length of 40mm pipe to join them together.

[You many be able to pinch a bit from the 600mm vertical pipe for this purpose - see what your washing machine User Manual says about the requirements.]

[David Hansen]

On Fri, 22 May 2009 03:03:30 -0700 (PDT) someone who may be [e-mail] wrote this:-

In addition to the information you have already been given, how long will the "horizontal" run of the washing machine waste be, precisely how and where do you intend to connect it and what fall do you intend to use?

Depending on how the soil branch is ventilated you may need to use an anti-siphon trap or an air admittance valve on the washing machine pipe. I would be tempted to try it without one and see what happens, practical engineering. If there is any gurgling in the trap when the toilet is flushed then remedial action is quick and easy.

[kdband]

Should be able to restrict the horizontal run from washing machine to around half a metre before we can cut into the soil pipe so fall shouldn't be much of an issue.

[Roger Mills]

On re-reading your original post, it looks as if you want to tap into a horizontal run of soil pipe rather than into the vertical stack. Is that correct?

If so, the strap-on bass which I suggested should still work - but you'll need an extra elbow to connect the washing machine trap to it. [Unless you connect into the *side* of the soil pipe, which I wouldn't recommend!]

[Doctor Drivel]

He is better off using a 40mm HepVo trap on the washing machine, which is tapped into the top of the soil pipe running to the toilet. Some WC bends have a knock out to fit a 40mm rubber boss into. Some like to cut into the

110mm pipe just before the wc bend and fit the 40mm pipe usinga strap on boss, as been gioven on Screwfix. A HepVo trap is an air admittance valve and an anti-siphon trap too - well it is a dry trap. The air admittance side of the trap ensures the toilet runs free. No need to try things out just fit a HepVo.

numbers: 15122, 15126

The trap is in-line. 40mm in 40mm out. Put a 40mm pipe stub on top, as long as you can get, so the washing machine drain pipe hooks in.

[Doctor Drivel]

He needs a HepVo w/machine trap as the 110mm pipe is long and a shallow fall. It allows air into the 110mm pipe from the 40mm trap giving free flow. Easy when you know how.