Can I fit a P trap outside?

[MrsRenovator]

I've just had a new boiler and am having to rejig my white goods.
Ideally I would like to move the tumble dryer 5" to the right, but there is a compression P trap in the way which is too deep.

If I fitted a longer drain hose on the washing machine, could I take that through the wall and fit the P trap on the other side of the wall? The external drain on the other side is actually in a shed, so frost free. Well, hard ice free.

Can you think of any reason why this wouldn't be a good idea? Or have you got any better solutions please?

 

[footprints]

If you are absolutely sure it will not freeze, it should work.
Is it possible to connect to the sink waste as an alternative?

 

[MrsRenovator]

Nope. Well, yes, But only with considerable ffaff.

I suppose any shed smells could come up the hose. Or wirse, vermin.
I wonder if I could form a slight U bend inthe hose behind the machine before sending it through the wall. Would that make a difference?

 

[footprints]

Smells and vermin not a problem that's what the trap stops.

 

[MrsRenovator]

Yes, I know what you mean. But of course the trap is usually indoors. The drain hose doesn't reach the water level, or it could siphon back..

 

[Hugh Jaleak]

Can put a bend on the waste where it comes through the wall and move the standpipe across to behind the washing machine? Alternatively, move the entire waste setup, including the pipe through the wall if necessary, so it's behind the washing machine? I wouldn't advise putting a trap externally, and the washing machine hose needs to be run in accordance with the manufacturers requirements, or you may have problems, with the machine, guarantee or both.

The U bend is to prevent odours coming back form the drain into the room, the washing machine drain hose is for just that, to drain the machine when required.

 

[MrsRenovator]

If you are absolutely sure it will not freeze, it should work.
Is it possible to connect to the sink waste as an alternative?

Ok. I'm going to try your idea of connecting it to a sink with an extension hose. But to do it, can you solve this problem for me please?

I will need a new trap for this sink. As you can see, there is only a very slight slope in the drain. How can I attach a WMC? All the traps I have seen have the outlet from the trap lowered to accommodate the drain spout.

I can't think how to get round it. Can you?

 

[Hugh Jaleak]

Outlet pipe will have to be lowered to accommodate an appliance trap, and extensions on drain hoses aren't ideal. What other options do you have?

 

[MrsRenovator]

My only other option is to leave the stand pipe where it is, but try to reduce the distance that the first bend stick out from the wall by about an inch. Either by cutting an inch recess into the solid wall for the compression nut to fit into. Or is there a glue/weld fitting that would turn that first bend more shallowly?

 

[Hugh Jaleak]

If that is solvent welded pipe, you can chop the wall out around it, and fit a bend to take the pipe to the right, virtually flush with the wall if need be, then use a couple of 45's to 'dogleg' the pipe back out slightly, or chop the plaster out to accommodate the compression nut, before fitting the standpipe behind the machine.

 

[MrsRenovator]

There we go. Solved! Thanks for your suggestions.
I have done what you said and chiselled out the wall far enough to accommodate the compression nut, and managed to loosen the pipe through the wall. So now I have connected the first compression joint of the stand pipe trap as tightly as is reasonable, then pushed it back into the wall.

Now I am going to foam the gap. The only problem I can forsee is that if that first joint leaks, it will leak inside the wall and I won't know until the plaster falls off. But I'll risk it!

Thank you for your help everyone!

 

[Hugh Jaleak]

To be honest, there's hardly likely to ever be any pressure on that joint, any leak will only be a weep, and then only when machine is emptying. If in any doubt, replace the washers before you fill the hole, and provided it's not disturbed, it shouldn't be a problem.