Is this right?? Soil stack in a new build house

[Aazzy]

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• Aazzy
• 15 Jun 2018

Drawing

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• Aazzy
• 15 Jun 2018

2nd 90’

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• Aazzy
• 15 Jun 2018

1st 90’

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• Aazzy
• 15 Jun 2018

Cut hole for access

I’ve had issues with a new build I’ve recently moved into.
Basically I came across my internal soil stack with 2 x 90 degree bends in it with.
This is the wet part of the soil stack and has two bathrooms above it.
I always understood that at most you could only have a slight offset the the soil stack. Also there is pipe from the bath that connects to the horizontal part between the bends. This is also all tucked away between the ceiling of the open plan ground floor and the floor of the bathroom above. So no access usually.
You always know when some one is using the loo as you can hear the flow lol.

I can’t seem to find anything on line about this apart from an offset.
So I’m trying to find out if this is totally wrong an I can have a few choice words with the builder or weather it’s acceptable and I’ll try and shove some insulation around it.
I’ll try and attach a rough drawing I’ve done
Any info would be much appreciated:0)

 

[Hugh Jaleak]

Building Regs, Part H, section 1.27. "Offsets in the wet portion of a discharge stack should be avoided. if they are unavoidable, then in a building of not more than 3 storeys, there should be no branch connection within 750mm of the offset."

Whilst that setup is not ideal, (and poorly planned), I dont think in itself it is a breach of regs. What I would be concerned about is that side branch connection, which in my view, is too close to the bend, (well within the 750mm, although that's usually referred to in the vertical plane), and may become a problem with waste from above splattering inside the soil pipe and causing issues with the connected bath.

 

[Aazzy]

Thanks for the info Hugh,
So the two 90 bends are passable although far from ideal. It’s more of the branch connection that is the real issue. I.E. being within the 750mm. It makes sense as I would guess you would want a decent drop to make sure the waste has a chance to get round the corners with out causing too many issues.
So should I be having a word with the builders about this??
I’m only an electrician so not too sure about where I stand with these muppets on the plumbing.
I doubt if I’ll ever buy a new build again, so many issues lol

 

[Hugh Jaleak]

Personally wouldn't fit it or want it left like that, bath waste would be better rerouted to connect into a vertical section in my view, but having seen some of the bodges that pass off as drainage on new builds, standards seem to be very lax now in some places.

The noise issue could probably be eased with some sound deadening, but my concern would be with falling waste hitting the bottom of that bend and making a mess internally and/or causing issues with the bath waste. Whoever designed it to be like that needs a rocket.

 

[John D v2.0]

90 degree bend is a no no, should be a rest bend or other long radius bend.
regs or not it's just terrible design really.
basically as Hugh said the designer (or lack of) needs a rocket.
The bath waste can't really enter the stack with all those corners.

I'm guessing someone changed the design elsewhere and the drainage guy just had to deal with it when he arrived, so that was the nearest viable bodge.

 

[dilalio]

I'm guessing someone changed the design elsewhere and the drainage guy just had to deal with it when he arrived, so that was the nearest viable bodge

Exactly! Architects and builders are the main culprits (and homeowners on a refurb). They are more interested in the number, size, location and type of rooms than what services need to go to them - for electricians it's not so much of an issue as wires are small and don't need falls, but for us plumbers, we're often left with the joys of finding a route as opposed to having them appropriately provided for us

 

[Aazzy]

Morning guys.
I’ve attached a couple more pics . Do you think the soil stack could be moved over the new position as per rough drawing??
There is room I think in the boxed area at the end of the bath. I know it has some built in shelving but two 45 degree bends surely must be better than two 90 degree bends !!
Or would there still be an issue with the toilet pan connection??
You guys have been very helpful so far :0)
I just want some ideas I can chuck back to the builders.

 

[John D v2.0]

That would be a million percent better. Still shouldn't have the loo entering opposing the main run entry strictly speaking due to cross flow risk. But either way it's still a tonne better. If you could take the loo in a 135 degree branch it would be more perfect. Same goes for the bath waste

 

[Hot&Cold]

I just want some ideas I can chuck back to the builders.

Aazzy,do you experience a plumbing defect/fault when using the bath or wc ? flow noise can be reduced by other means.

 

[OvertonPlumber]

Its a internal soilpipe within a building. It has had to have been tested by either Building control or NHBC. Its design and implementation has also been certified as compliant with building regs. If its wrong or leaking it needs to be rectified by the builder at there cost.

 

[Aazzy]

Aahhh mr benchmark,
Well you would presume that it’s been tested, Designed, etc. but alas I’m not totally convinced...
Reason for this is I’ve had a few issues which do not comply with building regs.
Such as no insulation within a sealed loft to the front porch area. I have even had building control ( who was the council) and NHBC involved with that.
I even found that my banister on the landing was only glued together as it popped apart one day ggrrr.
So you can see why I have a few doubts...
An yes I fully expect the builder to rectify any issues at there cost.
I expect a few snags with a new build, but alas there has been a few major issues. All rather worrying and stressful.
But less of my woes hehe.
I was after some info about the stack pipe, weather it conforms etc. :0)
On the whole it seems there may be an issue with the 750 mm spacing between the bends and coupling of the toilet pan to the stack. An if I’m reading it right. The actual bends and possibly the bath waste are passable but poor and could cause issues later down the line.
Now if the pipe work was out side I wouldn’t worry so much as I would have easy access, but due it being installed in the ceiling void I don’t want to have to cut holes to gain access further down the line when it gets blocked lol

 

[Hot&Cold]

Aazzy So where is the water leak also consider condensation running down the pipes.

if its a new build consider getting a surveyor in to create a full snagging list,developers will take more notice from a trained professional than a home owner. funny old world