I've not seen this waste setup before - how to relocate sink?

[liftfan]

Hi,

The existing waste setup in the kitchen is a bit unusual! The waste enters a drain via a hopper, inside the house, which then goes all the way under the house to a manhole at the front.

I want to move the kitchen sink and connect to that existing drain. The new sink will be against the side wall. It's not an option to just run a new waste out the back of the wall where the new sink will go.

I was thinking of running a new waste from the sink and through the old cavity as shown in blue below then somehow connecting to that old clay pipe. Is that possible?

Thanks

 

[oldbutnotdead]

Thats very odd.
You'll struggle to get enough fall from the new position to drain into that existing gulley at ground level, you need to carefully dig round the gulley and see what is there.
The answer is probably yes, you may need an aav near the sink.

 

[liftfan]

Odd indeed! That whole hopper thing needs to go as it's above floor level. I've no idea why it was done that way.

 

[Madrab]

Almost as if that drain and clay gulley would have been outside the original footprint of the house. If it wasn't then unlikely that would have been part of the original setup as that shouldn't have got past BC.

To make use of that drain you will need to cut the floor and dig down, remove the gulley and then look to connect an adapter then a boss/branch to the top of the drain to accept the waste run then backfill.

 

[oldbutnotdead]

Almost as if that drain and clay gulley would have been outside the original footprint of the house. If it wasn't then unlikely that would have been part of the original setup as that shouldn't have got past BC.

To make use of that drain you will need to cut the floor and dig down, remove the gulley and then look to connect an adapter then a boss/branch to the top of the drain to accept the waste run then backfill.

I was wondering whether the kitchen had had a joke extension in the past- can't see any good reason for an internal gulley otherwise

 

[liftfan]

Almost as if that drain and clay gulley would have been outside the original footprint of the house. If it wasn't then unlikely that would have been part of the original setup as that shouldn't have got past BC.

To make use of that drain you will need to cut the floor and dig down, remove the gulley and then look to connect an adapter then a boss/branch to the top of the drain to accept the waste run then backfill.

Yes, originally designed to be outside was my thought as well. House is 1970's so I suppose they just did what they liked although it was a bespoke build for the original land owner.

As you say I'll dig down and see. How about running the new waste in that cavity? -It's about 70mm wide so was thinking 50mm waste pipe, long sweep bends.

 

[Hugh Jaleak]

Best option would be, as said previously, dig down and expose the pipework under the hopper. (It could even have a trap under there!) Once exposed, you should be able to carefully dismantle the old stuff, it looks like HepSleve, (note which is slightly different sizing to the current Hepworth Clayware, Supersleve.) Once back to a suitable point, fit a suitable collar to get you from Hepsleve to Plastic, come back up with 110mm plastic to a suitable height, fit a Boss, and run your 50mm from there under the screed, I really wouldn't be putting in the cavity!

I would look at some sort of access, e.g. a 110mm rodding access at floor level just in case you have issues in the future.

Direct connection to the drain is common practice, it's just an odd choice of fitting to do it with, using a hopper as opposed to the correct collar, with waste adaptor connections.

 

[liftfan]

Best option would be, as said previously, dig down and expose the pipework under the hopper. (It could even have a trap under there!) Once exposed, you should be able to carefully dismantle the old stuff, it looks like HepSleve, (note which is slightly different sizing to the current Hepworth Clayware, Supersleve.) Once back to a suitable point, fit a suitable collar to get you from Hepsleve to Plastic, come back up with 110mm plastic to a suitable height, fit a Boss, and run your 50mm from there under the screed, I really wouldn't be putting in the cavity!

I would look at some sort of access, e.g. a 110mm rodding access at floor level just in case you have issues in the future.

Direct connection to the drain is common practice, it's just an odd choice of fitting to do it with, using a hopper as opposed to the correct collar, with waste adaptor connections.

Great info thanks. I'll post some pictures after I start digging!

 

[liftfan]

Finally got to round to doing this.

Here is what it looks like. You were right Hugh Jaleak, there is a trap/u-bend under there. I've just put my hand in there to clear it out. Nice! The start of the clay pipe is level with the foam (bleach) in the picture. It's about 190mm below the floor level.

Best option would be, as said previously, dig down and expose the pipework under the hopper. (It could even have a trap under there!) Once exposed, you should be able to carefully dismantle the old stuff, it looks like HepSleve, (note which is slightly different sizing to the current Hepworth Clayware, Supersleve.) Once back to a suitable point, fit a suitable collar to get you from Hepsleve to Plastic, come back up with 110mm plastic to a suitable height, fit a Boss, and run your 50mm from there under the screed, I really wouldn't be putting in the cavity!

I would look at some sort of access, e.g. a 110mm rodding access at floor level just in case you have issues in the future.

Direct connection to the drain is common practice, it's just an odd choice of fitting to do it with, using a hopper as opposed to the correct collar, with waste adaptor connections.

 

[Hugh Jaleak]

Not sure what you are planning, but just in case, that Trap needs to come out, then make a direct connection onto the drain.

 

[liftfan]

Not sure what you are planning, but just in case, that Trap needs to come out, then make a direct connection onto the drain.

Is that in case it blocks in the future?

Thanks

 

[Madrab]

Is that in case it blocks in the future?

Thanks

(spelling edit) Wouldn't think so, it just isn't needed. You wouldn't normally have an open trapped hopper/gulley internally like that, unless it was outside at one point. So it just needs removed and a direct waste/soil connection to the main run installed.

 

[Hugh Jaleak]

Is that in case it blocks in the future?

Yes. Especially if not easily accessible, apart from the unholy mess involved when trying to clean these out. Fat, soap, food scraps, ec can and do build up, resulting in a stinking black gunge. in the bottom of the trap. Unpleasant enough when outside, really wouldn't want to be sorting it out inside.

Secondly, in your situation it needs to be a sealed connection to the drain, as it's internal. You don't want to be unsealing it again to unblock it in the future.

 

[liftfan]

Great info once again, thanks. I'll start digging!

 

[liftfan]

After spending a few hours getting dusty here is what I've found. The trap is joined with Hepworth sleeve to a clay pipe that runs horizontally (with a fall) under the house.

Do I remove that sleeve and fit a flexible adapter like this:

Flexible Adaptor Clay to PVC

If you’re working on an older house or building that has plumbing fixtures made of both clay and PVC, you’ll be in need of an adapter. If this is the case, try this clay-to-PVC flexible adaptor. It’ll mean you can connect clay fixtures to new PVC fixtures without the risk of leaking or...

www.toolstation.com

I can't see how I'm going to get some vertical pipe in there so instead do I fit a stub of pipe horizontally with an end cap. Then put a boss on to feed the waste pipe like I've drawn below?