DIYer - need help with toilet pipe air-valve install

[pc__upf]

Hi,

New to the forum - hoping to get some help here.

I am rerouting my toilet to have the pipe work hidden in the eaves.

Bath/shower/basin waste connects to the toilet drain via Barco Bos.

I need help with the air vent.
- Do I need one for toilet, and another for shower/bath/basin waste?
- Do I need one for each bath, basin and shower?

Where is the best location for the air valve (or valves)?

Many thanks for your help.

 

[chris watkins]

Is the stack vented to outside air or is there another stack on your system that vents?
What is a Barco Bos?
What size is the waste float picking up the bath & shower & how long is the run to the bath?

 

[Rob Foster]

I fink op means a strap on or glue boss to put the 1 1/2 inch waste into the 4 inch. If its inch and quarter ..uck. chking

 

[Chuck]

Four 90-degree bends and no rodding-points? Sewage doesn't run up-hill, and it doesn't like corners much either.

 

[Rob Foster]

Four 90-degree bends and no rodding-points? Sewage doesn't run up-hill, and it doesn't like corners much either.

Yea, Op probably needs a re think, maybe we can help him
off out chking

 

[ShaunCorbs]

Boxing and run to the right off the toilet

 

[Rob Foster]

Boxing and run to the right off the toilet

logical, cheaper and better chking

 

[pc__upf]

Gents, thanks for your replies.

Yes, perhaps not the most logical approach but I'd like to try before giving up. This will make space available that was previously unavailable.

The bos (or boss) connects the 40mm on to the 4 in pipe.

It is not going uphill - there is a drop of about 450mm from toilet outlet to outside stack. Is this sufficient?

The stack can be vented outside, but will it take care of the basin/bath/shower pipe venting?

Adding rodding point to the planning.

 

[Riley]

I would say it will block in no time at all have you contemplated 45° bends

 

[pc__upf]

I have contemplated 45° bends, but they really complicate things. Pipe going in between joists, etc.

For what it's worth, i'm using wide 90° bends (don't know the actual name). Still bad?

 

[Riley]

It’s more the proximity of the bends. Every turn causes resistance and friction to the nasties trying to run away. Sometimes the easy option isn’t the right one

 

[ShaunCorbs]

Swept bends (what there called)

 

[pc__upf]

Thanks ShaunCorbs.

Riley -
would swept bends solve the problem in my planned setup, or do you still find them a problem?

 

[pc__upf]

or what about long radius bends? even if they're underground bends?

110mm Underground 87.5d Long Radius Bend Floplast | Speedy Plastics

 

[Riley]

I wouldn’t were it me and based on the angle there you are eating up more and more space

 

[Riley]

I’m also not being pedantic but I suspect your run from the shower to the drain is too long for 1.5”

 

[Sharp Point]

The bath on emptying will pull the seal out of the shower. Each appliance should each have its own waste ideally to the stack and not all joined up.

 

[Coby kenny AGUILAR]

See if you can substitute the 3 x middle 90° for 2 x 45°'s

If its already an internal stack take it high and fit a durgo if it's external take it past the highest outlet inside

Not all outlets / sanitaryware need a vent, unless it's pulling a trap ect..

If you want to play it safe fit anti-syphon trap under bath and basin there not that much dearer than a normal trap

 

[chris watkins]

The 40mm waste pipe will pull any water filled traps on the all the fittings when the bath is drained Part H of the building regs sets out the maximum runs for single runs to single fittings once you start combining them then you need to increase the waste pipe size or add an anti-siphon pipe or mini AAAV or replace the water filled traps with waterless traps.
The stack should be ventilated, the branch to the WC doesn't have to be but I would be tempted to run a 50mm anti picking up the WC & the bath (40 or even 32mm) if at all possible, run above overspill level of the pan & connected back into the dry part of the stack (vent pipe). In that way no mechanical devices would be required.
Medium radius bends are fine so long as the float is installed with the correct falls (18 - 90mm per M) de-bur the pipes & you will not have any problems.
https://assets.publishing.service.g...achment_data/file/442889/BR_PDF_AD_H_2015.pdf

 

[pc__upf]

Thank you all for your replies - very helpful stuff.

Ok, so install anti-syphon traps on shower/bath/basins.

AAV or Durgo on 40mm pipe. Inside eaves ok? see diagram.

AAV/Durgo not required for toilet, but better if it has it? Or definitely required? Or not needed at all?

I'll attempt to use 2 x 45° bends instead of the first 90.



Did I capture everything? Thanks again everyone.

 

[pc__upf]

The 40mm waste pipe will pull any water filled traps on the all the fittings when the bath is drained Part H of the building regs sets out the maximum runs for single runs to single fittings once you start combining them then you need to increase the waste pipe size or add an anti-siphon pipe or mini AAAV or replace the water filled traps with waterless traps.
The stack should be ventilated, the branch to the WC doesn't have to be but I would be tempted to run a 50mm anti picking up the WC & the bath (40 or even 32mm) if at all possible, run above overspill level of the pan & connected back into the dry part of the stack (vent pipe). In that way no mechanical devices would be required.
Medium radius bends are fine so long as the float is installed with the correct falls (18 - 90mm per M) de-bur the pipes & you will not have any problems.
https://assets.publishing.service.g...achment_data/file/442889/BR_PDF_AD_H_2015.pdf

@ChrisWatkins - many thanks, very helpful.

Is this what you mean?

 

[chris watkins]

@ChrisWatkins - many thanks, very helpful.

Is this what you mean?

View attachment 38193

No, you don't need & probably shouldn't have a "Durgo" on the main stack, can't terminate to atmosphere ? if it can then the loop is find but not essential it is more to try to anti the bath run so it will not self-syphon when discharged. Otherwise couldn't you run it separately along the eaves to connect directly to the stack?
Remember this work is covered by Building Control & you should be talking to them.
Please don't use anti-vac traps you may well live to regret it.
Try this type of trap = Sanitary waste valve in bathroom applications

 

[pc__upf]

Thanks Chris,

With a waterless trap I can now reroute the bath and connect directly to the toilet's 4 in. (See diagram) because it can go above joists.



This ok?
https://www.NoLinkingToThis/p/osma-...qAosAERuxAzb8d-yeEAaAmbpEALw_wcB&gclsrc=aw.ds


About the AAV - should it go on the 4 in behind the toilet, or the shower/basin 1.5 in?

 

[Riley]

Are you running the shower waste through joists

 

[pc__upf]

It was like that when we bought the house.