SVP at New Flat Roof Level

[dunclane]

Hi all,

Having a new rear extension and the SVP needs to be moved to drop in the corner of new extension, the centre of the SVP is bang on the level the wall plate for new joists needs to be fixed.

I've tried to show in picture below: -

1. New Extension wall in Grey
2. Line of Wall plate in yellow
3. The new SVP position

My query is is it ok to stop the wall plate either side and have the SVP to come out of wall on a 90 degree bend then fall down below joists to corner?
Also my plan is to terminate the top of the SVP with an AAV opposed to going through the roof.

All comments and ideas welcome, thanks.

 

[23vc]

Assume you can’t go 5 inches higher and clear it due to max eaves height allowed?
The extra bend isn’t ideal and wouldn’t be accessible for rodding but there’ll be loads like this (and worse) out there.
I’d go for a 45 degree on the lower bend rather than a 90.

 

[dunclane]

Assume you can’t go 5 inches higher and clear it due to max eaves height allowed?
The extra bend isn’t ideal and wouldn’t be accessible for rodding but there’ll be loads like this (and worse) out there.
I’d go for a 45 degree on the lower bend rather than a 90.

We could go higher and clear it but it would leave a parapet height of only 95mm or so at its lowest point due to roof fall.

 

[noseall]

Hi all,

Having a new rear extension and the SVP needs to be moved to drop in the corner of new extension, the centre of the SVP is bang on the level the wall plate for new joists needs to be fixed.

I've tried to show in picture below: -

1. New Extension wall in Grey
2. Line of Wall plate in yellow
3. The new SVP position

My query is is it ok to stop the wall plate either side and have the SVP to come out of wall on a 90 degree bend then fall down below joists to corner?
Also my plan is to terminate the top of the SVP with an AAV opposed to going through the roof.

All comments and ideas welcome, thanks.

View attachment 380520

There appears to be foul drainage directly below the WC wall exit. Why not do away with that bonkers long horizontal run, and drop the loo straight down?

 

[Hugh Jaleak]

Looks quite likely there may be a shared sewer running along the back of the houses, I assume you've ascertained where the sewer is, who's responsibility it is and obtained any necessary build over agreement from the Water Company?

That aside, dropping down slightly before going across to the new stack position should be ok, however I would never remove an open vent and replace with an AAV, vents are required and fitted for a reason. Given that, and the location of the window above the proposed position, I would also look at Noseall's suggestion, to run the new stack vertically where the existing branch comes through the wall, (boxed in inside extension), and continue straight up to vent. Kitchen wastes can be connected to the stack if required.

 

[robinbanks]

Can you move the toilet? What does the room above look like inside?

 

[noseall]

Can you move the toilet? What does the room above look like inside?

To where?

It looks to me like the loo is already up against the bath/bed wall as it is. My thoughts are that the SVP was moved, when they extended so as to carry out work on that new window. If they are extending then the window will no longer be an issue and they can reinstate the stack where it was previously.

 

[robinbanks]

To somewhere where its outlet is more convenient, like outboard of the grey line. I was assuming the small 3 panes window was the bathroom, and had space underneath the window (ie if the sink is there swap them over). This is why I asked for a pic of what the room looks like inside. Moving the toilet could save a whole load of messing about piping poop at ceiling level in the new extension

 

[23vc]

My answer assumed (a) there was a desire to have the downstairs open plan without a vertical soil pipe boxed in mid way through it and (b) remodelling the upstairs bathroom was out of scope