Soil stack to 110 drain -- the wrong way and right way

[TerryE]

All of the underground fittings seem to show the underground 110mm terminating in a 110 push-fit female connector at ground level and you simply slot the bottom section of your soil stack into this.  OK, I should have thought this one through when we did the slab but I didn't.  What we did was to just use a piece of the straight generic 110 pipe that the slab crew provided which now comes out of the floor and which the guys seemed to view as standard practice.  Our intent was and is to trim these to at or near slab level after the pour.  See photo below. 

Osma do a female 110 push fit to male rubber sleeved insert as below, but the issue that we have is that our toilet connector from our toilet joins the stack at ~145mm above slab level so this is too tight.  Can anyone recommend a lower profile M/F soil-underground  connector or alternative approach?  This can't be an uncommon problem.  I really don't want to start to chip out concrete to recess one of these

[ProDave]

What's wrong with cutting the pipe about 50mm above ground and a standard double socket straight coupler, or in the case of the toilet a branch fitting?

That fitting you show has a completelty different seal arangement, a bit more like that of a pan connector.

[Jeremy Harris]

I found that a swept branch fitted with no problem at the bottom of the stack for our downstairs WC.  I ran a length of 110 along the wall behind the WC, put another swept branch on that which led out to the WC connection then fitted a bend at the end pointing upwards with a reducer to take the waste from the basin and next door utility room.

[Nickfromwales]

There should have been a double socket straight connector on the top of each upstand . In that, blank caps fitted to stop the concrete failing in, but most importantly to protect the fitting and its internal rubber seal. 

I'd not even consider using that fitting as I only ever use those for picking up from a clay soil pipe. The internal bore is too far reduced to be putting that at the START of the stack, sorry. Hire a 6" core drill, make a 6" hole in some 18mm ply as a guide, lay the ply on the floor and centralise it over the stack. Core drill down around 75mm and remove the spoil, then cut the soil just shy of the FFL and then attach said coupler. It's a bit of a pita but if I was there, that's what would be happening.

Don't kango out around the pipe or you'll scratch / damage it and be unable to get a seal when you offer the fitting on. 

[TerryE]

At least we got this advice now   And for the benefit of others who might end up going down this shit hole, so correct method is:

Or if your slow bend is lower add a short section of pipe which has a female socket at slab level or a straight pipe section with a double socket again aligned to slab level.  Fill with a blanking cap whilst the slab-work is going on.  And if I recall Dave actually had his cap about 1cm below the slab level so making power floating easier, and he then tapped this 1cm out after the slab had gone off.

And now back to my cock-up and how we mitigate this.  A few clarifications:

• When you say a double socket straight connector, are you meaning double push-fit (p/f) or would you use p/f+solder fit using PVC-U solder for the lower socket which is going to be resealed in the concrete?  My inclination would be to use the latter rather than p/f upwards against the flow direction.  That assumes that we've done the test on a piece fo soil pipe to make sure that the solder socket and the pipe are solder compatible.
• We have two soil pipes and only one has a ground floor toilet branch attached.  The other has rodding access and a lower spigot to the utility sink waste.  Surely if solder fit is compatible then can't I just position the double socket above the slab?
• Lastly if you are suggesting using a double p/f, then why not just use a triple socket branch direct onto the soil pipe and solder the bottom socket?  We can use solder to expansion converter for the top socket to give the required expansion.

      It's just that doing the 6" core is going to be costly and risky -- if anything goes wrong then what is plan B?  So if I can avoid this, I will.

[Nickfromwales]

How much 110mm is above slab height currently?

[RandAbuild]

Terry

Can't you use a shorter male to female connector like this:

http://www.toolstation.com/shop/p96056?mkwid=sK9AILCg1_dc&pcrid=46335772463&pkw=&pmt=&gclid=CJKXo73Ezc0CFXMz0wod8GsIHA

or http://www.pipekit.co.uk/shop/10559-Drain-Connector?gclid=CJvX66vIzc0CFa0V0wod7C4Ksg

This would give you more space to fit the wc. You may need to cut the pipe as it looks like it extends a long way above ffl.

I appreciate Nick's argument about not using these at the start of the stack and they are intended to different locations, but what would catch on such a joint? It is 110mm pipe, and only a few years ago we were using 4". As long as you keep nappies out you should be OK?

We only have one internal stack now and it has just been put in - it looks like this...

[TerryE]

@Nickfromwales About 30cm

@RandAbuild Finishing off a single WC is easy because there are standard F/M fittings for this.  Our problem is that this stack as well as the G/F toilet+basin also goes into the bathroom and takes another 2 toilets, 2 basins, a shower and a bath.  As Nick says, we really need a smooth straight-bore connection from the internal 110 to the bit sticking out of the slab.  A cement femail / pushfit double connector would be fine apart from fitting in the branch to this toilet on this stack.

[Barney12]

I must be missing something? Surely you can just add a coupler? http://www.drainageonline.co.uk/110mm-Drainage-Pipe-and-Fittings/110mm-Drain-Coupler.htm

[Declan52]

Can you not just use a 110mm slip collar and make sure pipe is cut square and filled smooth so there are no jaggy edges on it. Will give you a collar at the top to which you can attach whatever you want.

[RandAbuild]

Barney12

Yes, that looks like it would work. Does it give you enough roof to get the GF WC in?

Edited June 29, 2016 by RandAbuild

[Nickfromwales]

It's just down to good practice tbh. Reducing the bore at the start of the stack would be a no-no for me.

Anyhoo. 

A ground floor WC will have a 7" pipe centre ( from FFLevel ) where the soil leaves the pan. You'll need a fall in the pipe before it gets to the branch, thus determining the lowest point of the branch. 

An U/G ( underground ( terracotta coloured )) fitting with 3 sockets may JUST do it IF the socket is IN the slab NOT above it.  

I'll measure one later and double check.

[warby]

Does this help: http://www.drainagepipe.co.uk/products/ring-seal-soil-grey-86/92-5-double-branch-grey-soil-609.aspx

 

[Jeremy Harris]

If the pipe's cut dead square and with a slight chamfer on the inside top edge I can't see why there would be a problem with just fitting a normal swept branch on to it.  It's nice to have a socket poking up at exactly the right height out of the slab, but my guess is that this is very rare.

We have a swept bend, just like the one illustrated above, under our slab.  However, because the insulation is 300mm thick and the slab another 100mm thick, the swept bend is way below finished floor level.  We therefore had a tall stub of pipe sticking up out of the concrete, with a plastic cap taped on it to ensure it stayed clean.  When I came to fit the swept branch at the base, all I did was very carefully cut the pipe to length, making sure it was dead square, with the required external chamfer to go into the fitting and a very light internal chamfer.  The pipe abuts against the stop inside the branch which is, by design, fractionally smaller than the ID of the pipe, specifically to ensure that there's no upward-facing lip to catch anything.

On one external 110mm pipe connection (the one from the kitchen waste external trap to the inspection chamber) the only way I could fit it was with a slip coupler.  These have no internal lip, so it is essential that you cut the ends of both pipes absolutely dead square.  I'm sure there is probably a tool for doing this, but I made up a jig, using a bit of 6" x 6" x 1/4" aluminium alloy angle that I happened to have.  I stuck it in the band saw and made a dead square saw cut through 3/4s of it, and I then used this to cut all the pipes dead square.  I found that this made life very easy, as I just marked where I wanted to cut on the pipe with a Sharpie, put the jig on so I could just see the black line in the slot, duct taped the jig to the pipe (both sides), then used a wide mitre saw blade in a hacksaw frame to cut the pipe.

The wide mitre saw blade is better than any other saw blade, IMHO, as it is wide enough to stay square in the jig and has no kerf on the teeth, so doesn't wear the jig away, plus it makes a cleaner cut through the pipe.  To clean the inside of each pipe end to get a very slight chamfer I used a self-aligning metal deburring tool (like this:

To chamfer the outside of pipes fitting into push-fit connectors I just clamped my belt sander into a Workmate at the right angle, turned it on then rested the pipe in the gap in the Workmate bed and rotated it against the belt.  This gave a nice even outside chamfer every time, and only needed a quick scrape with a Stanley knife blade to get the fluffy bits off.

[TerryE]

@Barney12 the coupler that you mention wont give me the depth to include a branch

@warby I am using one of these on the first floor for the two toilets but I only need a single branch on the ground floor.

@NickfromwalesNick, if I have 2½° fall-away from my pan that about 5cm so the branch centre should be around as far as I can see the pipe centre at the branch needs to be around 12cm above FFL or 13½cm above the slab. However I have a Gerberit with wall hung pan so I can play around with the connection height a little as well as the gradient, so I could get away with around 15½cm or so.  That's enough to fit a D/SW Single Branch such as the one below, which requires 152mm.  OK I still need an expansion gap on the pipe but I 've got a rodding access immediately above this which I could make push fit at the top or I could use the converter kits which convert a solder fit socket to a push fit one.

As Jeremy points out I will need to be anal about getting the cut accurately square which is going to pain in the arse given the position of the pipe but I can make a jig and use a tenon saw and finish off with the old woodworkers trick with a sharpie.   And this is still dependent on being able to solder the PVC-U 110 drain to a PVC-U 110 stack branch. 

Anyway having done a bit of cut and paste from the OSMA catalogue this is what I am looking at (C=152mm):

[Jeremy Harris]

That's exactly what I have.  Works fine. no problems at all. 

FWIW, it's exactly what's at the bottom of the stack in our 1983 built bungalow, too, as unforeseen problems before we sell have resulted in me having to rip out and replace the separate WC (the cistern has just cracked, and as it's a lovely green suite in there we've decided to bite the bullet and replace it all before we stick the house on the market).

[PeterW]

Is that a solvent weld joint at the bottom or a push fit ..?? Solvent has to be perfectly aligned so put it all together and a sharpie mark at two points from the pipe onto the floor so you get it spot on when it's glued up 

[Tennentslager]

34 minutes ago, JSHarris said:

it's a lovely green suite in there we've decided to bite the bullet and replace it all before we stick the house on the market).

No...not a jade green one! 

Pics please...must be worth a fortune somewhere to someone.

Saw some tv show that had different colours of reclaimed stuff in their bathroom.

Yellow sink, purple bath etc.

Horribly brilliant

[Barney12]

There is quite an established market for supply of coloured/discontinued sanitaryware. They are used quite extensively by the UK insurance market now that "matching items" clauses have become common place in almost all but the premium insurance product ranges. One example being: http://www.brokenbog.com but there are others.

Edit: to clarify my own post as its not particularly clear; Almost all buildings insurance cover these days does not cover you for matching items. I.e. If you were to break your basin the insurer can replace it with a basin that doesn't match the suite. The right to repair any item is also now common place in policies. 

Edited June 30, 2016 by Barney12

[Nickfromwales]

Ah, good point about the 'user definable' height with the adjustable frame of the Geberit. The last one I fitted I purposely jacked up by a good 35mm, above normal WC pan height, as the punter had bad knees. There are 'comfort' height floor standing WC pans around, as well as Doc M suites which also adopt a higher pan level. All jokes aside, and believe me I've done well here to fight the urge, you may well find it a good idea to jack the height up a bit for comfort, and the side effect will be the ease of connection for the ground floor loo. 

Im not sure about where the hang ups are coming from with having a pushfit at the base of the tee, eg a triple pushfit socket tee, as using double socket connectors, bends and 45's etc is commonplace. 

1 hour ago, PeterW said:

Is that a solvent weld joint at the bottom or a push fit ..?? Solvent has to be perfectly aligned so put it all together and a sharpie mark at two points from the pipe onto the floor so you get it spot on when it's glued up 

Amen to that. You get one shot with these. 

[TerryE]

36 minutes ago, Nickfromwales said:

I''m not sure about where the hang ups are coming from with having a pushfit at the base of the tee, eg a triple pushfit socket tee, as using double socket connectors, bends and 45's etc is commonplace. ...

You get one shot with these. 

Thanks Nick. As you said you only get one shot and whilst the solvent working time is ample for a 50mm pipe or smaller, this is a 110mm joint in an awkward position.  Normally, if the odd joint goes wrong then you say shit and at worst you might need to cut the pipe to use an inline double socket to rotate it or whatever.  For this one joint, it would be a case of having to core down through 75 mm of concrete and rebar as you first suggested -- at a minimum.

On reflection I think that I'll go with a pushfit. As long as the riser is cut nice and square and finished properly there shouldn't be any issues.

[Nickfromwales]

It's what I would do, and have done on just about every stack I've ever connected to. No issues yet, and I'd assume that if shitty black and grey waste water had been leaking anywhere, particularly inside the envelope of a customers home, I'd be the first to know . 

[Jeremy Harris]

8 hours ago, Tennentslager said:

No...not a jade green one! 

Pics please...must be worth a fortune somewhere to someone.

Saw some tv show that had different colours of reclaimed stuff in their bathroom.

Yellow sink, purple bath etc.

Horribly brilliant

 

8 hours ago, Barney12 said:

There is quite an established market for supply of coloured/discontinued sanitaryware. They are used quite extensively by the UK insurance market now that "matching items" clauses have become common place in almost all but the premium insurance product ranges. One example being: http://www.brokenbog.com but there are others.

The cistern has had it, sadly, and it's a close coupled one, which means that the toilet may well be no use without it.  The small washbasin might come away from the wall cleanly, I'm not sure how it's fixed (seems to be just screwed to the wall without brackets).

The green is what I think was popularly called "avocado" in the early 1980's when it was installed.  The bathroom was the same, but I ripped that out years ago and got rid of it.  There's some "nice" green cushioned vinyl flooring in there too, along with floor to ceiling pale green wall tiles on every wall.  Whoever built this house liked green a lot.....................

[PeterW]

8 hours ago, TerryE said:

 

On reflection I think that I'll go with a pushfit. As long as the riser is cut nice and square and finished properly there shouldn't be any issues.

Have you got a MultiMaster or one of the other multi tools ..??

Makes it much easier to cut the pipe level as you can attack it from all the way round quite easily. 

[Nickfromwales]

A new hand saw such as a Jacksaw is my weapon of choice. Nice wide blade to keep the cut straight and true. The multi tools tend to melt / cut through so be prepared to have to do some extra de-burring if you use that. I do use them for this task occasionally, but only in adverse situations.