Does the main soil stack have to be completely vertical?

[me]

I can't seem to find any examples of a soil stack that doesn't have a main, completely vertical part, into which all the toilets join via branches. Now is this because there are bulding regs specifying this or it it just not common practice to have a "bent" vertical soil stack?

What I want to do is go out from the loo to a T branch as the first joint on the outside, so there'll be a vertical up and vertical down joint available. The vertically up joint of the T will go vertically over the roof line with a swan neck. The vertically down joint immediately joins to a 92.5 bend which then goes via an almost horizontal pipe to another 92.5 bend which then continues vertically to the ground. Access panels on the T branch and the second 92.5 bend.

Any problems (bulding regs wise)with that setup?

[Phil L]

None whatsoever. As long as the 'horizontal' part has a slight fall, even a
few cm, then there shouldn't be a problem. I've even seen them completely
horizontal and they've been like this for decades without problems.

[me]

Thanks Phil, but does it also comply with buildinbg regs? As you know, what works in practice and what the building surveyor will allow can be two different things!

[Max Demian]

On 22/04/2017 19:28, me wrote:
> I can't seem to find any examples of a soil stack that doesn't have a main, completely vertical part, into which all the toilets join via branches. Now is this because there are bulding regs specifying this or it it just not common practice to have a "bent" vertical soil stack?

Why do all soil stacks in a row of houses have a vent at the top? Surely
they all connect to the same sewer? Shouldn't venting the sewer be the
responsibility of the water board (or whoever installs it)?

--
Max Demian

[Phil L]

If it's part of a new build or an extension, ask the inspector next time he
does a site visit.
If it's only taking one WC, you can go as low as 1:80, which roughly
translated is 30mm over a 2.4m run of pipe.

[Phil L]

They're only surplus to requirements when everything is running smoothly.
If you had no vent on your stack and you got a blockage at the bottom of the
garden, most solids will collect there over weeks before you realise it, and
in that time, if gasses build up, they can't escape via next door's vent so
they tend to come up through your toilet as one giant turd flavoured drain
burp.

[Andrew]

Err, without the soil stack vent, when you flushed your toilet, or even
when an upstream neighbour flushed their toilet the vacuum could suck
out your WC water trap allowed nasty niffs into your house.

Building regs allows for at most, every 3rd house to have an internal
Durco valve instead of a vented stack. It does the same thing, by
allowing air into the stack when there is a pressure differential,
but doesn't work in reverse.

[dennis@home]

On 22/04/2017 20:13, Phil L wrote:

Aren't they there to stop siphoning of the bends. You can replace them
with an air admittance valve.

[Bob Minchin]

I have a horizontal (2.5 degree fall) run from a loo about 2.5 m long.
It was passed by BCO in 1985 without query.
There is a rodding point where it joins the stack

We are in a hardwater area and over about 30 years the bottom of the
pipe run surface has become covered in a shit coloured chalky hard
deposit which increases the friction to flow and it can block a bit
after "heavy" use.
A possible solution is to rotate the pipe with a strap wrench through
about 60-90 degrees to give a new smooth surface. If yet to try this
just in case the push fit seals then object leading to a worse problem!

[The Natural Philosopher]

On 23/04/17 11:32, Bob Minchin wrote:
> We are in a hardwater area and over about 30 years the bottom of the
> pipe run surface has become covered in a shit coloured chalky hard
> deposit which increases the friction to flow and it can block a bit
> after "heavy" use.

Brick acid. Or get yourself a water softener

Brick or patio acid is reasonably conc. hydrochloric and the 'cement'
will fizz and give off stinky CO2 but will dissolve quite fast.
it needs a puddle upstream to stay there and eat away at it. Too much
will be wasted. A cupful in the loo every flush for a week or two



--
"If you don’t read the news paper, you are un-informed. If you read the
news paper, you are mis-informed."

Mark Twain

[Tricky Dicky]

You get some weird arrangements in Victorian properties especially where the original building has been sub-divided. My daughters and SIL's first property was a an upstairs flat above what originally was quite a large Victorian shop with upstairs store rooms. The property was sub-divided into smaller units of mixed commercial and residential. In the lounge area of the flat was a low shelf boxed in below with a platform in one corner for a TV. This shelf went the full length of the window wall and partially along a dividing wall to next door. It turned out that this "shelf" and boxing in contained the soil pipe from next door running approx. 8m horizontally through their property before exiting outside to drop down to the sewer. Their own waste pipe did not join this as their bathroom was in a rear extension and the soil pipe went vertically down through the commercial property below. I always wondered who would have to foot the bill if ever there was a leak on the part passing through their lounge?

Richard

[Andrew]

On 23/04/2017 12:04, The Natural Philosopher wrote:
> On 23/04/17 11:32, Bob Minchin wrote:
>> We are in a hardwater area and over about 30 years the bottom of the
>> pipe run surface has become covered in a shit coloured chalky hard
>> deposit which increases the friction to flow and it can block a bit
>> after "heavy" use.
> Brick acid. Or get yourself a water softener
>
> Brick or patio acid is reasonably conc. hydrochloric and the 'cement'
> will fizz and give off stinky CO2 but will dissolve quite fast.
> it needs a puddle upstream to stay there and eat away at it. Too much
> will be wasted. A cupful in the loo every flush for a week or two
>
>
>

My grandparents house in Epsom had a lead stack outside the house,
going right down into the ground and a lead connection into the
toilet on the 1st floor. A builder bought the house in 1993 when
she died and I suspect the value of the scrap lead more than covered
the cost of a new plastic stack.

Don't think a cup of acid every week would have been a good idea.

[The Natural Philosopher]

would be if its covered in lime

Very little lead sewage systems.

Been clay subsurface/cast iron above since first installed. Latterly PVC.

--
“It is hard to imagine a more stupid decision or more dangerous way of
making decisions than by putting those decisions in the hands of people
who pay no price for being wrong.”

Thomas Sowell