Toilet waste pipe placement

[Jeremy Harris]

11 minutes ago, Barney12 said:

On a related note: One of my soil pipes (in the downstairs WC) which comes up through my slab has a wobble and will turn. They were solvent fittings so I can only assume no cement was used I'm now paranoid the other joints including 2 runs of 50mm waste to the sink and shower positions are buried under the slab with no solvent bond Feck!

 

I may be wrong, but aren't all underground waste pipes supposed to be push fit, to allow for a small degree of movement?  I think I remember reading this somewhere, and mention being made of things like slight settlement and the compressive effect of concrete as it cured.  The O ring in the push fit fittings allows for this very small amount of movement, IIRC.

 

Do you know how far down the soil pipe joint is?  I faced the problem of having to delicately chisel out around ours to just ease it inwards slightly by a few mm, and I knew that the push fit joint to the rest bend was below the level of the stone under the slab, so I was paranoid about accidentally lifting it out of the fitting and having stone fall into the open end..............

[Barney12]

12 minutes ago, JSHarris said:

 

I may be wrong, but aren't all underground waste pipes supposed to be push fit, to allow for a small degree of movement?  I think I remember reading this somewhere, and mention being made of things like slight settlement and the compressive effect of concrete as it cured.  The O ring in the push fit fittings allows for this very small amount of movement, IIRC.

 

I don't know about that point. The penetrations through the slab were the responsibility of MBC (albeit that they subbed the initial slab work out, who in turn subbed it out again) and they supplied the materials in that regard. They actually supplied 32mm and 40mm solvent weld fittings. I had them changed to 50mm.

 

14 minutes ago, JSHarris said:

Do you know how far down the soil pipe joint is?  I faced the problem of having to delicately chisel out around ours to just ease it inwards slightly by a few mm, and I knew that the push fit joint to the rest bend was below the level of the stone under the slab, so I was paranoid about accidentally lifting it out of the fitting and having stone fall into the open end..............

 

No, I don't think its too far down. Looks like I'll have to get the SDS drill out and do some gentle digging.

 

 

[Jeremy Harris]

All our drains were put in place by our ground works team, so we already had pipes and ducts poking up where I thought they were supposed to be before the foundation team arrived on site.  I think all the foundation team did was replace the capped stub soil pipe that the ground works guys had left with a longer bit of pipe, to make sure it poked up well above the slab.  They couldn't shift it's position, as the rest bend was firmly bedded in the underlying trench.

 

TBH, I didn't think you could get solvent weld underground soil pipe, I thought it was all push fit. 

[Nickfromwales]

1 hour ago, Barney12 said:

On a related note: One of my soil pipes (in the downstairs WC) which comes up through my slab has a wobble and will turn. They were solvent fittings so I can only assume no cement was used I'm now paranoid the other joints including 2 runs of 50mm waste to the sink and shower positions are buried under the slab with no solvent bond Feck!

Nobody should have used solvent weld to come up through the slab imo. It's too brittle and gives no movement in the joint whatsoever. 

If the fittings and pipe weren't de-contaminated / cleaned prior to solvent CEMENTING, NOT just solvent weld then the joint will fail regardless. Are you 100% sure this was a solvent fitting? Good news is you could remove the stub of pipe, and diamond core drill down to meet the offending fitting. You could then clean and re-make the joint. Not ideal, but better than a two-finger salute. 

[Declan52]

One of the advantages of doing a block build is that you can see where the walls on the ground floor are so there ain't no excuse for being that far out from the wall. With a timber frame with a slab type foundation you really have to put the hard yards in and measure and check it and check it again or pipes will be in the wrong position.

Never used any kind of solvent weld for these kind of pipes. They are just greased up and pushed fully home. 

[Jeremy Harris]

I did a quick bit of hunting around and I can't find anyone selling underground solvent weld pipe, either.  All the underground stuff seems to be push fit.

[AliG]

1 hour ago, Declan52 said:

One of the advantages of doing a block build is that you can see where the walls on the ground floor are so there ain't no excuse for being that far out from the wall. With a timber frame with a slab type foundation you really have to put the hard yards in and measure and check it and check it again or pipes will be in the wrong position.

Never used any kind of solvent weld for these kind of pipes. They are just greased up and pushed fully home. 

 

I have a block build, my builders still managed to put 2 pipes on the wrong side of a wall!

 

Looking at the comments I am not alone, I could see that pipes were out of line just by looking, but in the end they just went ahead and cemented them in before fixing them as discussed here.

 

@nickfromwales you are right (as usual  ) I didn't have a close enough look at the DPC. I think my guys did cut into the subfloor also and they had a bit more room to maneuver as my cisterns are all concealed so they were coming up inside a bulkhead.

 

 

[Nickfromwales]

I haven't yet met a problem that I couldn't fix. Just be nice to not have to do it....but wheres the fun in that eh?

[Onoff]

57 minutes ago, Nickfromwales said:

I haven't yet met a problem that I couldn't fix. Just be nice to not have to do it....but wheres the fun in that eh?

 

Last Night an ex DJ Saved My Life

 

"There's not a problem that he can't fix 
'Cause he knows all the tricks
And if your pan gives you trouble…"

 

'Cause away goes trouble down the drain 

Said away goes trouble down the drain

 

Well alright"

 

It was even by Indeep!

 

 

 

 

 

[Barney12]

6 hours ago, Nickfromwales said:

Nobody should have used solvent weld to come up through the slab imo. It's too brittle and gives no movement in the joint whatsoever. 

If the fittings and pipe weren't de-contaminated / cleaned prior to solvent CEMENTING, NOT just solvent weld then the joint will fail regardless. Are you 100% sure this was a solvent fitting? Good news is you could remove the stub of pipe, and diamond core drill down to meet the offending fitting. You could then clean and re-make the joint. Not ideal, but better than a two-finger salute. 

 

Yep. They definitely used solvent for the 110 and the 50mm. P*ssed off now  

[Nickfromwales]

Ass

[Nickfromwales]

Holes

[Nickfromwales]

1 minute ago, Barney12 said:

 

Yep. They definitely used solvent for the 110 and the 50mm. P*ssed off now  

Have you / they pressure tested?

[Jeremy Harris]

Just now, Barney12 said:

 

Yep. They definitely used solvent for the 110 and the 50mm. P*ssed off now  

 

 

What colour is it?

 

Underground rated pipe is orange or brown, indoor/outdoor rated pipe is either black, grey or white.  As said earlier, I can't find anyone selling underground pipe that's solvent weld.

[Nickfromwales]

Just now, JSHarris said:

 

 

What colour is it?

 

Underground rated pipe is orange or brown, indoor/outdoor rated pipe is either black, grey or white.  As said earlier, I can't find anyone selling underground pipe that's solvent weld.

Maybe just the bend and upstand is AG and the rest UG ( orange ) 

[Jeremy Harris]

8 minutes ago, Nickfromwales said:

Maybe just the bend and upstand is AG and the rest UG ( orange ) 

 

 

But the bend at the bottom should be a rest bend, and aren't they only available as UG?

[Nickfromwales]

2 minutes ago, JSHarris said:

 

 

But the bend at the bottom should be a rest bend, and aren't they only available as UG?

Yes, and yes. 

[Jeremy Harris]

4 minutes ago, Nickfromwales said:

Yes, and yes. 

 

Thanks, I thought so. 

 

More investigation needed by the sound of things, as a rest bend is needed at the bottom of a vertical soil pipe in order to ensure it remains clear (because it has a much bigger bend radius than a normal bend) plus a rest bend has a support to allow it to be firmly embedded and not move under normal vertical loads.  If there's no rest bend at the base of this then that needs looking at, in my view.

[Onoff]

I did glue brown to grey with solvent weld and solvent weld FILLER as I mistakenly ran a length of brown in my wall rather than grey. Although both PVC they're different BS numbers. The brown feels softer/more resilient/less brittle. Even when cleaned with IPA and roughed up the brown doesnt "melt" as well. Though the assembly passed the water test I did go over the top with CT1. Fingers crossed!

 

 

 

[Jeremy Harris]

The brown stuff seems to be a three part sandwich when you sand a taper on the end to ease a push fit.  There's the brown inner, then a whitish looking almost foam like core, then a brown outer.  Might explain why it doesn't solvent weld very well.

 

I wonder if  @Barney12 has a proper push fit underground rest bend, deep down, then a length of solvent weld AG pipe coming up through the slab.  That might help explain the wobble and the fact the pipe rotates.

[Nickfromwales]

31 minutes ago, JSHarris said:

The brown stuff seems to be a three part sandwich when you sand a taper on the end to ease a push fit.  There's the brown inner, then a whitish looking almost foam like core, then a brown outer.  Might explain why it doesn't solvent weld very well.

I've seen that type of UG pipe a few times, but it's not the norm . 

Ive also seen the AG with the same sandwich but I cannot remember forvtye life of me who makes it ( or why tbh ). 

 

Note :

AG = above ground - grey / white / black etc UV resistant. 

UG = underground - typically terracotta / orange. Non UV resistant. 

 

[Onoff]

Page 4 here shows two variations on the terracotta stuff; solid wall and foam core:

 

http://www.polypipe.com/sites/default/files/Terrain_Underground_Broch_July_201376.pdf

 

Not got a clue what the bit I used was...unless I can find the offcut!

[Barney12]

3 hours ago, JSHarris said:

 

 

What colour is it?

 

Underground rated pipe is orange or brown, indoor/outdoor rated pipe is either black, grey or white.  As said earlier, I can't find anyone selling underground pipe that's solvent weld.

 

I had a quick look this evening and managed to pull the protruding (orange) pipe out. Was in a bit of a hurry so didn’t take pictures but it looks like it goes from orange, to a grey solvent boss and back to orange. The boss will be serving the 50mm white solvent weld pipe to the shower and sink. It doesn’t look like it’s very deep in the slab so digging it all out won’t be too much of a challenge but still a complete PIA!! 

 

Ill try try and take some photos tommorow. 

[Nickfromwales]

2 minutes ago, Barney12 said:

 

I had a quick look this evening and managed to pull the protruding (orange) pipe out. Was in a bit of a hurry so didn’t take pictures but it looks like it goes from orange, to a grey solvent boss and back to orange. The boss will be serving the 50mm white solvent weld pipe to the shower and sink. It doesn’t look like it’s very deep in the slab so digging it all out won’t be too much of a challenge but still a complete PIA!! 

 

Ill try try and take some photos tommorow. 

That makes more sense. Pics would be good.

[Jeremy Harris]

It does make sense, and my experience has been that some of the the underground stuff doesn't bond as well as the grey/white/black stuff.  I tried to fabricate a sort of water spillage catchment tray thing under our water filter, to catch the drips when changing filters and direct them down a bit of waste pipe, using a left over bit of the orange stuff, and the adhesive didn't really work well, even with the pipe cleaned and primed with a wipe of MEK.  The second one I made was fine, that used a left over bit of the grey stuff.