SVP question

[Robbox]

Not sure if this should be in Building section, but I have the SVP going up one corner in the bathroom. The bathroom is in need of total refit and this SVP really gets in the way. The bathroom is narrow (1650mm) and not very long. I'd like to fit a 1600mm bath/shower across the end where the SVP is, but it's in the way and simply bringing the bath forward means we lose 200mm of valuable space. So I thought of two alternatives (well three really, but the third is the really expensive option).
One idea is to reduce the SVP to 75mm and have the bath (Bette) with a corner cut.
The other idea is to put a bend in the SVP and take it through the wall outside, where it can go up to roof level. I am certain there is enough space under the bath at the head end to accommodate the bends and the T junction.
Can one make the SVP less diameter above any inflows?
Our walls are 500mm stone, so taking through wall is a tough option. making it down to 75mm could ease that.
The third option is taking the whole SVP outside and connecting up to the outside drainage....that's the really expensive option!!

 

[muggles]

You can have the ventilation part of the stack in 75mm with no issues at all. You could take it out through the wall as you suggest, nothing wrong with that apart from it possibly looking a bit odd

 

[picasso]

reduce it to 75mm and bury it in the wall, when you get above the ceiling rejoin back to the original stack.

 

[Robbox]

I just found a 110/50 reducer on their site. It's offset, so that makes it a bit easier.
I agree, chopping out a 50mm channel in the corner could be the 'solution'. then I could make a reverse connection to the 110 pipe in the roof space!
I wonder if there is any recommended distance above the tee from the WC. Don't any over active hurds trying to defy gravity

 

[muggles]

You can't go down to 50mm, 75mm is the minimum for a ventilation pipe

 

[Robbox]

any ideas where I find a 110/75?

 

[muggles]

Plumbers merchants

 

[compheat]

what about fitting a Durgo valve and cut out the vent all together

 

[muggles]

There needs to be an open vent somewhere on the system

 

[Robbox]

I thought about a Durgo, but it would have to fit under the bath and I am certain it would fail because the basin overflow is higher than the durgo.
I have done an internet search and can only find a 110/82 reducer or a 110/50 reducer, not yet found a 110/75. I have checked out the manufacturers sites, Marley & BES...nada.
Because the SVP is in the corner, I am thinking about this route. The shower bath I want is Bette and they do all their baths with a corner cut. So if I reduce to 82 or 75, I can hopefully place the vent pipe right in the corner and have the bath as tight up to it as possible.
Then again I may just break through the wall and vent to the outside.

 

[muggles]

Sorry my bad, 110 to 82 is what you need, I still use proper phrases like "four inch" and "three inch"

 

[Nige F]

You can't go down to 50mm, 75mm is the minimum for a ventilation pipe

only if the pipe police are likely to see it

 

[kirkgas]

Sorry my bad, 110 to 82 is what you need, I still use proper phrases like "four inch" and "three inch"

haha ya oldie

 

[Robbox]

going down the route 'take the svp out the wall' all told it seems the simplest. Plenty of room under the bath to get the pipe bends in etc.