Soil Pipe Vent

[sotal]

Hope this is the correct section for this.

We live is a 30 year old house which has two toilets. The downstairs toilet simply drops straight into a soil pipe. The upstairs toilet goes into a vertical stack which is inside the house and goes through the tiles in the roof.

I realise that it requires some kind of vent but at the moment the pipe is boxed in and makes the bathroom 6" smaller as it holds the bath out so the hole wall is built out 6". I would like to put a P shaped bath in and need a few extra inches.

Is there anyway to do this in a different way now-a-days? I've seen internal one way valves but wasn't sure if they were for this purpose?

 

[Richard C]

The valve is called a AAAV (Durgo) & you can get both internal & external types. You use one of these but it only vents negative pressure & you can only fit one if there is another open vent (stack) on the drain system; it must be installed above the highest flood point & accessible for maintenance. It may or may not help depending on your room layout & the stack location.

The other alternative is to reposition the stack down the outside but this will involve moving/fitting a new rest bend & connection to the underground drain invert.

 

[sotal]

Hmmm, thanks for that don't think that would work then!

Pipe can't go on outside as it would look terrible and would have to go through the porch outside the front door.

It is the only vent on our house and it wouldn't really be possible to add another.

It also would have to be under the bath which I doubt would be high enough for the toilet next to the bath.

I may get away with just reducing the size of the boxed in area. From the look of the pipe that comes out of the the tiles it certainly isn't 4" pipe, I believe it is 85mm (but can't check) how far down could the thinner 85mm run?

All the other houses on the cul-de-sac look to be the same with the pipe running insdie and out through the tiles.

Any other ideas at all?

 

[Richard C]

If you share a drain with neighbours this may provide the necessary positive ventilation, as long as they don't fit valves as well. You can’t fit the Durgo under the bath, the wash basin is usually the highest flood point rather then the W/C but may not be in your case. You can reduce the dry part of the stack but it would be unwise to reduce the wet part although in some cases, this is permissible.

You could fit a macerator but they are a real pain when the get blocked (I’ll leave it to your imagination why) which it almost certainly will if you have children & probably will if you don’t.

 

[sotal]

Yes the hand basin is the highest point, fitting a durgo at that height won't benefit me at all.

Going to have to rethink it a little I think.

Thanks very much for the advice