Help!: Reducing Soil Pipe

[janzbro]

hi everyone, is it possible to reduce the diameter of the soil pipe from the toilet to the stack.

Just found out the house has an internal stack and the toilet waste goes through the wall into the airing cupboard and then drops down stairs.
This is leaving me with limited space across the back wall to fit a 1200 x 900 shower tray and fit a stud wall boxing in the soil pipe and the shower hot/cold supplies as I only have 1325mm wall to wall.

I could put a stud under the soil pipe and build a stud frame above it then board the wall, this would leave the p/board touching the soil pipe but Im worried about movement of that upper frame.

Any ideas on framing out or reducing the soil pipe would be much appreciated.

[365drills]

Probably need more info!


When I first read post this is what I assumed you were asking. To reduce the stack.

But I think you want to box in a soil stack with the minimum of plasterboard. Is that right?



I boxed in the whole back wall then jammed the loo up against the tiles.

But I think you are saying you need to sacrifice space for a shower. Assuming the soil stack is fixed (cant be altered) then all you can do is work with the space you have. It may mean a 1000mm tray.

[tommyzooom]

Do you want to box in the pipe in a corner, If so WEDI do a preformed corner for this purpose, will save you some room

[janzbro]

sorry it was as clear as mud wasnt it

The main aim as you point out is to get the 1200 x 900 tray in

I was thinking if I could reduce the soil pipe diameter (only for approx 900mm where it runs between the tray and the wall at one end , that this would allow me to get some studs in from floor to ceiling and board it out (so hiding the waste and shower supplies).

[simhopper]

From a plumber, you can not reduce the bore size of the soil pipe

Anything above the toilet wc connection level, as long as it is a vent only could be reduced to 3", if the stack continues to feed upper floors/flats then it must remain 4"

You have 135mm, which if the frame is done correctly should allow enough space, if you are worried about the framework touching it why not chisel away any plaster and fit he soilpipe snug against the brickwork

[janzbro]

not worried about the stud work touching it is just gettting the stud work solid, as it the wall the shower / mixer will be on and be fully tiled inside a cubicle and dont want the water getting in a the tiles falling off

dont suppose you could explain how to do it or sent me a pic

Ive got 135mm left

Soil pipe = 105mm
Stud frame 4"x2" = 105mm x 52.5mm
P/board = 12.5mm

Im not sure how you would do it because at the least with the stud side on it would take up 170mm - well over what I have

[simhopper]

not worried about the stud work touching it is just gettting the stud work solid, as it the wall the shower / mixer will be on and be fully tiled inside a cubicle and dont want the water getting in a the tiles falling off

dont suppose you could explain how to do it or sent me a pic

Ive got 135mm left

Soil pipe = 105mm
Stud frame 4"x2" = 105mm x 52.5mm
P/board = 12.5mm

Im not sure how you would do it because at the least with the stud side on it would take up 170mm - well over what I have

You want to do something like this



This job was 4by2 timber bolted to the wall with hammer fixings, we did 4 horizontal timbers, We then screwed vertical 4 by 2 with plastic shim washers to level out.As you can see the soilpipe is free to be fitted at the bottom

[janzbro]

never thought of that, your a star

simple when you know how or see a photo

cheers you just saved me rethinking the whole project

[Swanseajack]

Also, could use 3x2 CLS for stud work instead of 4x2? Another option maybe to use a Durgo Valve, depending on stack layout.

[simhopper]

Also, could use 3x2 CLS for stud work instead of 4x2? Another option maybe to use a Durgo Valve, depending on stack layout.

You can not always use a durgo

All houses must have at least one vent to atmosphere, if his property is a one stack house then he must not use a durgo

[bighen]

You can not always use a durgo

All houses must have at least one vent to atmosphere, if his property is a one stack house then he must not use a durgo

Not quite true.

You work on a 1 in 3 principle. ie. every 3rd house must vent to atmosphere. the other 2 can utilize air admittance valves.

Knew my years in management would come in useful eventually

[simhopper]

Not quite true.

You work on a 1 in 3 principle. ie. every 3rd house must vent to atmosphere. the other 2 can utilize air admittance valves.

Knew my years in management would come in useful eventually

Different councils, different rules

When i have dealt with Edinburgh building control they have insisted on this

I would always prefer to vent to atmos, We had issues in a large developent of new flats where the durgos had been badly fitted, it was only when we tested that we found out the valves where not correctly seated

[bighen]

Scotland has a totally different set of rules to England.

Roof bracing/covering technique due to stronger winds
Plaster thickness - 5mm min
etc

But the NHBC stipulate the 1 in 3 rule to which all the councils in England I have dealt with accept

[Gazebo]

I am with bighen on this one. 1 in 3 vent to atmosphere, i only use AAV (dergo) when i have moved a w/c or extended the branch run into the SVP beyond 1.5m of the vent pipe.

I think that is the regulation.correct me if i am rusty on that reg.

[janzbro]

Im only moving the toilet location from 1m away from the stack on one wall to 1.5m away on another wall not going to be altering any vents just the soil pipe route

but concerning the stud work,

should I remove the old dot and dab plasterboard before attaching the stad or can/should I just stud over it ?

[365drills]

If it were me I would start from scratch.

Thats what I did when I rebuilt the studwork and changed the soil stack for this loo.



The soil stack was laid out first.
The stud wall was rebuilt to conceal it.
To reclaim lost space, niches were cut into the wall above the soil stack for storage.
The whole area was neatly tiles to conceal all pipework.