Moving basin plumbing ~3"

[andeekaii]

Hi all - long time lurker but first time poster!

I want to relocate the downstairs cloakroom basin drain about 3" closer to the wall to give enough clearance for a new washing machine (I know it's 32mm instead of 40mm but it's been fine for the last 2 years).

Will it likely involve 'simply' digging up the concrete around the pipe, extending 3" and then coming back up in the required location?
How deep is the pipe likely to be and is it likely to just have a bend underneath the concrete in 32mm and then continue in straight 32mm pipe under the floor towards the soil stack - or does it just 'drop' straight down into something? The reason I ask is because the waste in the kitchen drops straight down into a black rubber thing (boss adapter?) and it can just be pulled out - the 32mm pipe it doesn't go under the concrete.

Edit: the toilet/soil stack is in the opposite direction to the direction I need to move, that is why I am assuming it will need extending, not cutting shorter.

Thanks in advance,
Andy

 

[jj4091]

Wouldn't it be easier to build a plinth for the washing machine so that it clears the waste.

 

[Hugh Jaleak]

Afraid you're not going to know what's under there until you look. You may find you've a similar setup as you've described in the kitchen, if so it may be prudent to replace the Boss adaptor for a 40mm if you can access it easily enough.

 

[Madrab]

That looks like an old toilet pan location? If so you may find that pipe runs into a soil pipe with a 110mm to 32mm adapter below that floor level. If so and there's a soil pipe bend down there then that may require a bit of a different approach.

As suggested though, won't know until you get down there.

 

[andeekaii]

Wouldn't it be easier to build a plinth for the washing machine so that it clears the waste.

Unfortunately that won't be possible as we're fitting a basin (with side waste) on top of the washer and it's already going to be pretty tall (90cm to the worktop surface and 100cm to the top of basin)

Afraid you're not going to know what's under there until you look. You may find you've a similar setup as you've described in the kitchen, if so it may be prudent to replace the Boss adaptor for a 40mm if you can access it easily enough.

The kitchen boss was just visible without any digging. This one isn't. I wonder if its because this room has a thin layer of self levelling that has gone over it, whereas the kitchen doesn't as its located under the units and the self level only goes to the plinth?

That looks like an old toilet pan location? If so you may find that pipe runs into a soil pipe with a 110mm to 32mm adapter below that floor level. If so and there's a soil pipe bend down there then that may require a bit of a different approach.

As suggested though, won't know until you get down there.

It was previously a pedestal basin, but it's been temporarily (the multiple years kind of temporarily) repurposed as a washing machine while renovating. Now we're replacing with a new washer and intend to fit a basin on top. The current washer sticks out more than ideal so we're looking to get more clearance.

There are two options: A less deep washer (but might be giving up loading size or performance), or pushing the plumbing back (but might be opening a big can of worms)

 

[Madrab]

Ah ok, that's what the cutout was for in the flooring, was it ever a WC?

Same option though, you won't really know till you get in there.

 

[andeekaii]

Ah ok, that's what the cutout was for in the flooring, was it ever a WC?

Same option though, you won't really know till you get in there.

It's a new build (6 year old). It's always been a basinand yes the cut-out in the floor is where the basin used to be.

I think I'm just going to get a shallower washer - hope that is enough clearance and if it turns out not to be then get the tools out. Thanks for your help.

 

[Hugh Jaleak]

If the Gaff is just 6 years old, it'll be 110mm plastic under there, but no doubt the Groundworkers have thrown the drains in so although the 110mm should finish at or just below Finished Floor Level, it could be several inches down and the floor screed has covered up all manner of sins.