Does a soil stack + vent have to be 100mm pipe?

[larrylamb11]

Long story - short version, architect has designed bathrooms and shown soil stack on ground floor, but not at first floor.... and then put the shower over the point where the stack would rise vertically to a vent (discovered at first fix planning for plumber). My options seem to be, A) smaller shower plus false wall to give space for soil stack to reach roof... B) run vent in say 40mm pipe within wall space to roof, can you run a vent in smaller pipe or does it have to be soil pipe size? C) change soil stack 'run' to move it to another part of the building with easier access to the roof. D) try and cram a Durgo valve in somewhere - how high does a Durgo have to be above the toilet?

Added to this, there is a downstairs WC which will have a washing machine and sink tee'd into the waste - the 100mm waste pipe disappears into the concrete floor slab and joins with the pipe coming from upstairs at a Y before going on to the foul sewer. Will this run need a seperate vent or Durgo as well? i.e. do I need a vent upstream of every WC?

 

[Nige F]

Don`t cram a durgo in ..ask the build. inspector for his opinion = then ask the architect why he didn`t put the detail in And ask the plumber what he `d like to do with the pipework. Between them they should know.

 

[tamz]

Get back on to your architect and get him to sort it out, that's what he was paid for.

A) smaller shower plus false wall to give space for soil stack to reach roof

That's one option.

B) run vent in say 40mm pipe within wall space to roof, can you run a vent in smaller pipe or does it have to be soil pipe size?

No. You cannot do this. Smallest vent size you can use is 82mm

C) change soil stack 'run' to move it to another part of the building with easier access to the roof.

Another option

D) try and cram a Durgo valve in somewhere - how high does a Durgo have to be above the toilet?

? If you can cram a durgo in you could cram a vent pipe. Durgo needs to be above spillover level of basin.

 

[TicklyT]

......And ask the plumber what he `d like to do with the pipework.

....Then ask the plumber what he'd like to do with the architect.....

 

[tamz]

......And ask the plumber what he `d like to do with the pipework.

....Then ask the plumber what he'd like to do with the architect.....

They always end up getting paid for our advice

 

[larrylamb11]

Thanks for the thoughts yeah, the plumber can be in the cue behind me, the builder, the sparky and everyone else who wants to string him up... the number of scr*w ups has been beyond amusing. Anyway, we are where we are, so I will ask him for a brainwave and go from there..... it looks like false wall time and a hole in the roof to me.

Will I have to have a separate vent on the downstairs WC (with sink and washing machine waste into the same pipe) the soil pipe for which is connected at foundations level into the main horizontal foul drain running from the stack ?

 

[tamz]

Will I have to have a separate vent on the downstairs WC (with sink and washing machine waste into the same pipe) the soil pipe for which is connected at foundations level into the main horizontal foul drain running from the stack ?

Could probably use a durgo here up in corner of WC or utility. It will be around 900mm off the floor and any boxing in needs to be vented.

 

[kirkgas]

get him to foot the bill for alterations, inconvenience, and any other word you can add on