Drainage of 2 toilets

[frediaz]

is it "allowed" to use a branch connector horizontally to connect a second toilet to the pipe (110mm) going to the main stack like this?

 

[Softus]

Yes.

Look after your venting arrangements though.

 

[frediaz]

The main stack is ventilated through the roof. The picture is in side view by the way.

Ta

 

[Softus]

Hm. I'm rethinking this a bit.

Firstly, you don't need to use, and shouldn't use, a 'bossed branch' here.

So instead of this:

use this:

Secondly, what you're proposing is unusual, and whilst I can't think of a regulatory objection to doing it, it feels wrong to me.

The optimum pipe arrangement is for all branches to be horizontal and joining directly to the stack, with the only bend at the bottom of any vertical being the long/slow rest bend at the base of the stack (image below).

Compared to this, a bossed branch has a very tight radius on the bend - not best suited taking a vertical branch pipe. So, while I can't see that your design won't work, it isn't ideal.

 

[frediaz]

I was going to use the branch you propose, it's just that I used a picture of a bossed branch for my illustration. Marley have a manifold system for connecting the pipes from several toilets onto one common pipe going to the stack:
http://www.marleyplumbinganddrainage.com/index.cfm?path=specifier.design&PageID=10&RangeID=7
So why can't I do something similar using just one branch? otherwise I would need to find a way to connect two 110 pipes in the main stack

 

[Softus]

Given your statement that the first diagram was a side-on view, there is a vertical pipe coming from a WC.

How long are you proposing to make that vertical pipe?

 

[frediaz]

Just the height from the back of the toilet to the floor space under it

 

[frediaz]

I spoke to Marley technical advice. They told me I can use the branch turned through 90deg as on my diagram so long as the discharge from the toilet is down vertically into the 110 mm pipe. My toilet has the outlet at the back but they said it was OK to use a bend to take the pipe down to the main 110mm pipe.

I think it is only when you try to use the branch horizontally on the same plane as the main pipe that they do not like it.

 

[Softus]

I spoke to Marley technical advice. They told me I can use the branch turned through 90deg as on my diagram so long as the discharge from the toilet is down vertically into the 110 mm pipe.

I don't mean to upset the apple cart, but it's very easy for Marley to say that they're happy with your design when there's no possibility of it ever coming back to haunt them. If the BCO doesn't pass it then you can't do it.

My toilet has the outlet at the back but they said it was OK to use a bend to take the pipe down to the main 110mm pipe.

I don't get this point - how would you do it without a bend?

I think it is only when you try to use the branch horizontally on the same plane as the main pipe that they do not like it.

I think you're guessing, and I think it's a wrong guess.

 

[blondini]

I'm planning to arrange two WCs both discharging vertically to a common branch pipe running between the floor joists. The regs are here http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf and if I am reading them right it should be ok.

 

[frediaz]

If the BCO doesn't pass it then you can't do it.
I don't get this point - how would you do it without a bend?
I think you're guessing, and I think it's a wrong guess.

As on the previous posting, I do not see anything in the Building regs that prevent me from doing it like this.

I am talking about the fact that the toilet does not have to have an outlet at the bottom to discharge vertically into the main 110mm pipe

I am not guessing, I read the links that appear at the bottom of this thread, where some people have discussed similar situations

 

[Softus]

If the BCO doesn't pass it then you can't do it.

As on the previous posting, I do not see anything in the Building regs that prevent me from doing it like this.

You're one in a long line of people who believe they know what's in the Building Regulations without ever reading them.

Here's what the real ones say:

PART H DRAINAGE AND WASTE DISPOSAL
Foul water drainage
H1 (1) An adequate system of drainage shall be provided to carry foul water from appliances within the building...
.
.
.
Giving of a building notice or deposit of plans
12.—(1). . .
(2) This regulation applies to a person who intends to—
(a) carry out building work;
(b) replace or renovate a thermal element in a building to which the energy efficiency requirements apply;
(c) make a change to a building’s energy status; or
(d) make a material change of use.
(2A) Subject to the following provisions of this regulation, a person to whom this regulation applies shall—
(a) give to the local authority a building notice in accordance with regulation 13; or
(b) deposit full plans with the local authority in accordance with regulation 14.
.
.
.
(5) A person who intends to carry out building work is not required to give a building notice or deposit full plans where the work consists only of work—
(a) described in column 1 of the Table in Schedule 2A if the work is to be carried out by a person described in the corresponding entry in column 2 of that Table, and paragraphs 1 and 2 of that Schedule have effect for the purposes of the descriptions in the Table; or
(b) described in Schedule 2B.
.
.
.
SCHEDULE 2A
<nothing that excludes the work that you're doing>
.
SCHEDULE 2B
<nothing that excludes the work that you're doing>

I don't get this point - how would you do it without a bend?

I am talking about the fact that the toilet does not have to have an outlet at the bottom to discharge vertically into the main 110mm pipe

I don't know why you think that's relevant to anything.

I think you're guessing, and I think it's a wrong guess.

I am not guessing, I read the links that appear at the bottom of this thread, where some people have discussed similar situations

Chat is ok, but I see no point in basing a decision about your legal obligation on anything other than the Regulations themselves.

 

[frediaz]

The only one who is guessing here is you. How do you know I have not read the regulations? Do you know if I am getting inspections from the Council and the NHBC? What is the point of you participating in these forums to confuse people?

 

[Bamber gaspipe]

The only one who is guessing here is you. How do you know I have not read the regulations? Do you know if I am getting inspections from the Council and the NHBC? What is the point of you participating in these forums to confuse people?

Because he is a self obsessed plank who hasn`t had any attention for a while, ignore him & carry on. You are quite ok with what you propose.

 

[Softus]

How do you know I have not read the regulations?

Does it really matter how I know, when the fact is that you haven't?

Do you know if I am getting inspections from the Council and the NHBC?

I have no opinion about that; I've merely pointed out that you need approval, and that you aren't guaranteed to get it.

What is the point of you participating in these forums to confuse people?

Please show me where I've written anything confusing. If you're confused, then it's only because you think the Guidance Document (at the link posted by blondini) represent the Building Regulations.

Well, they don't.