Tue, 19 Dec 2023 04:42:20 +0000 http://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260517#Comment_260517 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260517#Comment_260517 Wed, 16 Aug 2017 14:20:11 +0100 Doubting_Thomas
I'm intending to avoid soil stacks going through the roof and want to do the lot with stub stacks and AAV's where required - this should be possible since we have a bungalow arrangement.

Looking at the levels, there'll be several items (bath and MVHR condensate drain) which will need to enter the main stack at a lower level than the main WC pipe (float?). I understand that certain manufacturers offer a collar boss arrangement that is designed to allow this without needing the standard 200mm separation to avoid backflow.

This is appealing, since we only have 50mm screed, then RC slab on insulation so I'm keen to keep as much of the horizontal runs above the FFL as possible. However I realise there may be horror stories with this so please share any ideas.

Likewise, draining the island unit dishwasher and sink is a challenge. What I've ultimately come up with is a separate run below slab, meeting in the nearest inspection chamber so everything can be rodded.

In terms of sizing, I've assumed 40mm pipe to everything but the WC's. 110mm stacks and whatever we need below ground. This is mainly to keep things 'simple' rather than mixing 32 and 40mm pipe but again if this is overkill it would be good to know.

Any opinions on solvent vs. push-fit?

Thanks in advance.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260518#Comment_260518 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260518#Comment_260518 Wed, 16 Aug 2017 14:24:19 +0100 Doubting_Thomas http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260520#Comment_260520 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260520#Comment_260520 Wed, 16 Aug 2017 17:07:30 +0100 djh
(1) I don't think you'll need AAVs on the sinks in the kitchen, but check with your plumber.

(2) I think the AAVs on the soil stacks need to be 110 mm units. Are they?

(3) Note that the 'WC manifold' will be somewhat lower by the time it gets to the second WC, reducing the height available for extra connections to the stack below the WC connection. Check carefully how it will all fit together - I ended up with the waste pipe from one WC on the first floor passing above floor level in my plant room since there wasn't space to put it in the floor void. Not a disaster but not very elegant either!

(4) Where is your vent pipe? Mine is a 3" steel rainwater pipe up the outside of the house.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260522#Comment_260522 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260522#Comment_260522 Wed, 16 Aug 2017 18:12:50 +0100 Doubting_Thomas
We definitely intend to use an approved plumber nearer the time, but I realised the number of above ground drops etc. will affect the below ground runs and therefore the number of penetrations through our slab - so it's yet another decision that we need to do earlier than I'd assumed because the slab is due to start fairly soon.

To answer in order:

1. I saw some fairly complex (loop vent?) plumbing arrangements for kitchen islands generally, so thought it best to allow for something here. Will check with the plumber once they're on board though.

2. Yes, the soil stacks are planned as 110 units. They'll probably need to be capped with a valve rated to sit below the 'basin flood level' as I'm hoping to conceal them within a vanity unit (or kitchen unit)

3. Noted. The multi-pipe collar boss ('8-way soil manifold) that I was looking at appears to allow for this with an adjustable bend for WC's so the hole remains consistent despite the fall on the pipe. I've attached an elevation of the current strategy but again this all needs checking with someone who knows their waste pipes.

4. As above, it's all single storey so I'm counting on being able to use a durgo valve instead of a standard SVP.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260524#Comment_260524 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260524#Comment_260524 Wed, 16 Aug 2017 19:46:26 +0100 tony
I would have an external vent pipe at the head of the run

I would run the kitchen sink shower and bath all to the same external gulley

I would run the two WC's on a good fall pipe into an external vent pipe collecting sinks and basins on the way

No drains under building, one pipe in screed to island sink]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260531#Comment_260531 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260531#Comment_260531 Wed, 16 Aug 2017 22:00:33 +0100 djh Posted By: Doubting_ThomasI'm counting on being able to use a durgo valve instead of a standard SVP.
I think it's your BCO that gets to make the decision as to whether you have one or not.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260566#Comment_260566 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260566#Comment_260566 Thu, 17 Aug 2017 16:58:55 +0100 Doubting_Thomas
I've asked our BCO about the vent pipe at the head of the run and the durgo valve / HepVo etc.

Tony, are you suggesting a single external gulley 'pot' that receives separate pipes out from kitchen sink, bath etc.? That sounds like a lot more holes in the outside wall. I was hoping to just use the inspection chamber from the drain as a rodding point, so I can't see what advantages the gulley brings.

Agree on avoiding the drains under buildings, but we only have 50mm screed + 10mm (?) finish. Even with 32mm pipe that's not a lot of cover. Do you think it's doable or would the screed just crack?]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260573#Comment_260573 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260573#Comment_260573 Thu, 17 Aug 2017 21:16:24 +0100 tony
Can't run sink and/or shower straight into a drain in my book]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260577#Comment_260577 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260577#Comment_260577 Thu, 17 Aug 2017 22:11:26 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260587#Comment_260587 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260587#Comment_260587 Fri, 18 Aug 2017 10:44:06 +0100 Doubting_Thomas Posted By: tonyChase pipe a bit into the concrete need 50mm screed minoften 65mm now

Can't run sink and/or shower straight into a drain in my book

Our S/E says we can't reduce the slab at all (it's a raft) so can't channel out below screed. Sinks will all have p-traps or bottle traps and run to a stub stack which sits over a drain (just as in the main stack to the bathroom).

Shower is intended to be walk-in wet room type, with a 'bottom outlet' gulley (plus bell trap) embedded in the slab - like a commercial kitchen. Outlet from gulley drops straight down to drain below. I can see how this might need to be vented as there's no stack to this branch, but will wait to see what BCO says.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260589#Comment_260589 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260589#Comment_260589 Fri, 18 Aug 2017 11:48:11 +0100 djh Posted By: Doubting_ThomasShower is intended to be walk-in wet room type, with a 'bottom outlet' gulley (plus bell trap) embedded in the slab - like a commercial kitchen. Outlet from gulley drops straight down to drain below. I can see how this might need to be vented as there's no stack to this branch, but will wait to see what BCO says.
My downstairs shower is also a wet room with the gulley/trap let into the slab, which is also a raft. We had reduced the depth of the slab in the area to make room for the trap but I still had to chisel out some more in the precise few square inches (after checking with the SE) because the depth wasn't quite enough.

I went for a side outlet because I wasn't confident that the vertical 110 mm waste pipe stub would be precisely under the waste position in the shower base former. The trap outlet is led by a short length of 40 mm pipe straight onto the top of the piece of 110 mm poking out of the slab. There's no need for a vent.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260590#Comment_260590 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260590#Comment_260590 Fri, 18 Aug 2017 14:00:15 +0100 MarkyP
Can you re-inforce the screed over the pipe? Some EML or EWI type mesh?

Does a crack even matter? What's the finished floor covering.

personally I'd chase in 20mm and mesh the screed.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260592#Comment_260592 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260592#Comment_260592 Fri, 18 Aug 2017 14:53:55 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260593#Comment_260593 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260593#Comment_260593 Fri, 18 Aug 2017 15:46:14 +0100 MarkyP http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260596#Comment_260596 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=260596#Comment_260596 Fri, 18 Aug 2017 21:35:14 +0100 djh http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=261954#Comment_261954 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=261954#Comment_261954 Sun, 08 Oct 2017 13:57:26 +0100 rocconut
I fitted push fit in our low energy build (27 years ago) for access/cleaning reasons. However recently have found that the rubber bung reducers/connectors to the 110 SVPs have failed and were leaking (7 out of 9). All pipework is internal so not down to UV.

Also, I was always taught that it was good practice to have a vent at the head of any drain run, so in our case ran the vent pipe internally to a ridge vent.]]> http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=262021#Comment_262021 http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=15235&Focus=262021#Comment_262021 Tue, 10 Oct 2017 10:37:24 +0100 Doubting_Thomas
Would be good to know from others whether there are similar failures with solvent systems of a similar age - I'm guessing they'd go brittle too, just with general plastic aging?

A standard ridge vent is unlikely to be airtight enough for us, but I'm still doing the research...]]>