Internal Soil Pipe

Cameron1590_2

Hello,

Looking to refit our bathroom and have a question on the internal soil pipe. 

Currently the pipe runs vertically up the one corner of the bathroom and is boxed in. It then vents into the loft space with an aav. 

If I could remove the boxing in and cut the soil pipe down to vent underneath the bath and fit a new aav on top it would enable me to get a large bath in (current bath 1.7m vs 1.9m due to the boxing in).

The question is, would I suffer any issues if I were to do this? 

I.e instead of the pipe ending in the loft with an aav fitted, it would now end underneath the bath with an aav fitted. 

Hope this makes sense. 

Thanks

MikeJXE

I'm not a plumber but yes Probably 

It would be lower than the basin and if there was a blockage in the drain would overflow into your bathroom

IMO it would be better to relocate it to outside 

grumbler

MikeJXE said:

IMO it would be better to relocate it to outside 

Unfortunately, AFAIK, the valve can't be outside (of a house)

Apodemus

grumbler said:

MikeJXE said:

IMO it would be better to relocate it to outside 

Unfortunately, AFAIK, the valve can't be outside (of a house)

I was assuming that MikeJXE was meaning conversion to a traditional vent stack, rather than an AAV?

daveyjp

The AAV needs to be above the highest drain in the system, which in a bathroom is typically the handwash basin plughole.

Newcad

I would imagine it could get quite smelly when th AAV opens.

Certain AAV's can be fitted externally but I don't really see the point - if your going outside anyway then just use a normal soil stack.

grumbler

Newcad said:

I would imagine it could get quite smelly when th AAV opens.

It opens to admit air into a pipe, not to release air. I have an AAV boxed (not sealed) in my bathroom and I've never felt any smell.

Certain AAV's can be fitted externally

Any links - to both a valve and the regulations?

Newcad

grumbler said:Any links - to both a valve and the regulations?

I'm new on here so don't have the required forum permission to post links yet.

Just change the httpx.

httpx://studor.net/en/pageid/newsitem-2017-05-22

Newcad

Ah, that last post did the job so:

https://studor.net/en/pageid/newsitem-2017-05-22

Norman_Castle

Can narrower rectangular pipe be used to reduce the area the pipe takes. The type often used for extractor fan venting? Is there similar watertight pipe for plumbing?

grumbler

Norman_Castle said:

Can narrower rectangular pipe be used to reduce the area the pipe takes. The type often used for extractor fan venting? Is there similar watertight pipe for plumbing?

Why rectangular, not round - especially as adaptors for ducting are 100mm and soil pipe is 110mm? If you mean rectangular with the same cross-section, then the difference in size will be minuscule - 11%.

I am no expert, but what I see is

Ventilation stacks serving buildings with not more than 10 storeys and containing only dwellings should be at least 32mm diameter

- https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/442889/BR_PDF_AD_H_2015.pdf , p.23

Not sure that I understand this correctly as people on many forums insist on 110mm, although this makes no sense to me.