Re-routing drains

[joshgroeny]

Hello - Is anyone able to advise me on the do and don'ts of changing my drainage runs please?

I'd like to build a conservatory at the back of my house coming off the kitchen and adjoining the rear addition to one side and the garden wall to the other.

The problem is my cast iron soil stack would go straight through the conservatory. I'm concerned that someone relaxing in the conservatory will have to listen to turds recocheting down the soil pipe whenever the toilet is used. Do I need building regs to reroute the soil pipe diagonally along the wall to waste at the rear of the addition? Am I opening a huge can of worms if I try this? The project is a total refurb of an 1850's Victorian house so I'm free to change pretty much anything although cost is definitely an issue...

It's got a London valley roof which has it's own drainage pipe so that will need re-routing as well unless I can combine the roof drainage and the soil stack somehow. Not sure if this is permitted...?

Should I avoid all this and just try to disguise the soil pipe (and noise)?

Thanks in advance for any ideas..

 

[Richard C]

Personally I’d just box it in with plasterboard & plaster it over. We’ve got a new soil stack running down the corner of our lounge from an en-suite above (no alternative really), it doesn’t make that much noise, it’s only intermittent use & we don’t really notice it.

Once you start moving soil stacks about, you will have to dig up & alter the underground drain invert as well, it could well end up a lot of work if it’s old & cast iron + there are regulations governing things like vertical offset in the dry section of a stack. But, if I’ve understood correctly, your cons. floor will be laid over the drain run! This is permitted (I’ve got one) but, obviously, any future problems will involve digging up the floor; which is not ideal. Personally, with a drain system that old, I would replace the section of drain under where the cons. is being built with modern plastic so at least you know the condition & it then will outlast the cons. Or you may be able to re-route the drain & move the stack killing 2 birds with one stone.

Draining your surface water into the public foul drain or even public surface water drain is not usually allowed now unless there is no other alternative; you may get away with it if that’s how it’s done at present but I would advise your ring your LABC & check.

 

[joshgroeny]

Hi Richard.. Thanks for the reply. I'm having to dig out the back anyway to bring the level in line with the kitchen floor so I will take your advice and expose the drain and check it. Incidentally, what is the minimum depth of soil I must keep between the drain and the cons. concrete floor? Any idea...?

Don't suppose you know of a good drain inspection service do you...? Pimlico charge a hair raising £170 minimum..

Thanks again,
Josh

 

[Richard C]

The lie & depth of the existing drain run & any inspection chambers will probably dictate what you do by way of replacement but this document covers current Building Regulations:
http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADH_2002.pdf

Cons. doesn’t (generally) come under Building Regs. but I would still advise you place a lintel over the drain run where it passes under the walls (see part H above); & use a continuous length of pipe under the cons floor so there’s no joins & potential leaks

Can’t help with drain inspection fee I’m afraid, why do you think you need one?

 

[Troll5]

I agree, its a lot of aggro to move the stack, when boxing it in is so much easier, cheaper, and shorter on time. However if i was to take this route, id fill the studwork with plenty of rockwool to dampen down any sounds, maybe double up on the boards too, theyre cheap enough.

 

[joshgroeny]

Thanks for your comments Richard and Troll5...

I figured I'd get the drains checked anyway as I'm down to soil in the whole downstairs floor and I'm weighing up whether to reinstate the suspended timber floor or go for a slab. Want to be sure the drains are sound before I cover tnem up with concrete..

Will be boxing in the pipe I reckon anyway!

Cheers,
Josh