Downstairs toilet extension

[Relentless81]

Hi,

Just had a builder round who I know has done a number of toilet extensions in my area.

He stated that the price will massively depend on where the drains run or if it can be done at all. He cant tell us the answer without digging up the paving and looking underneath to see where it runs. There is obviously a cost to this.

That's all fine, he doesn't have X-Ray vision. What I wanted to check is if there is another way to find out where the drains run, perhaps drawings, or the council will know. Has anyone been though a similar experience and worked out the drainage without having to dig up anything? Something rings a distant bell that it might be marked out somewhere?

Its a 1960's semi detached. Another thing he mentioned is that it should be singular drainage system, in others words the soil pipe and rain water drainage connect to the same underground pipes. I thought this was strange because in my mind I always thought they were two separate systems one for soil waste and one for rain water or is that only on modern builds or have I completely dreamt that up!?

Thanks

 

[ChrisD.]

Wouldn't they be on the plans for the house (if known)? Would have been part of the searches when you bought it.

 

[Borealis]

Older houses can indeed have a combined foul/stormwater drainage system. My parents have a 1950s house and all the gutters run into the foul water drains.

Do you know where any of the manholes are? That can give a fairly good indication of where the pipes might be running.

I reckon the council may have some information if work has been done on the house that required planning permission e.g. a previous extension that potentially built over drains.

You can pay your water company to provide an "asset location search" (that's what Thames Water call it), which will highlight all the drains, manholes etc. they believe to exist. Although it could come up with nothing, if there are no jointly owned pipes on your property.

EDIT: I live in a 2008 new build and the drainage search came back with nothing. Either Thames Water screwed up, or they haven't received the layout from the developer yet!

 

[Relentless81]

Wouldn't they be on the plans for the house (if known)? Would have been part of the searches when you bought it.

I've just been looking through all the paperwork on my lunch break and cant find it, I do remember something that resembled a diagram of the property marking out fence lines etc I'll have another look tonight though I dont recall having the drains on there but worth checking

Older houses can indeed have a combined foul/stormwater drainage system. My parents have a 1950s house and all the gutters run into the foul water drains.

Do you know where any of the manholes are? That can give a fairly good indication of where the pipes might be running.

I reckon the council may have some information if work has been done on the house that required planning permission e.g. a previous extension that potentially built over drains.

You can pay your water company to provide an "asset location search" (that's what Thames Water call it), which will highlight all the drains, manholes etc. they believe to exist. Although it could come up with nothing, if there are no jointly owned pipes on your property.

EDIT: I live in a 2008 new build and the drainage search came back with nothing. Either Thames Water screwed up, or they haven't received the layout from the developer yet!

Ok makes sense on the combined draining, mine is 1960. Just wanted to make sure he wasn't trying to get away with something he shouldn't but I don't get that vibe from him

No manholes on my property, others on my road have them on their driveway though. I reckon every other house has a manhole on their drive and the pipes route to them via the back gardens, this would be bad for us.

The house hasn't had any extensions, might still try the council though

Not sure its worth contacting the water company, I might try it but depending on how much it costs I might get a quicker answer from the builder who said he can raise the paving next week to have a closer look and its not a huge amount of money only £100 but its more the inconvenience of having it dug up when the kids use it a lot and any potential disturbance but I might be over thinking there.

 

[wandgrudd]

DYNO-ROD, (and i assume others) do drain mapping, some friends had it done when planning an extension it cost about £175 and you got a basic plan shown the outline of the house and the pipes marked on and the falls shown etc..

 

[Relentless81]

DYNO-ROD, (and i assume others) do drain mapping, some friends had it done when planning an extension it cost about £175 and you got a basic plan shown the outline of the house and the pipes marked on and the falls shown etc..

Interesting thanks I'll have a look into that

 

[Borealis]

Given that the water company search could well tell you nothing you don't already know and waste money I'd probably not bother with that option.

Getting a drainage specialist to do a survey would be the most comprehensive option. Yes it'll cost more than the builder lifting the paving, but the drainage people won't have to lift any slabs and you'll also find out if there are any other potential issues e.g. roots, cracked pipes etc.

 

[itsallaboutyou]

Deffo get a drain survey. Pretty reasonable really!

 

[tom_nieto]

Get a CCTV drain survey. This will tell you what you need to know without digging.

 

[DXP55]

I had blockage in my drains and after he had freed them up he shoved a camera down - Got talking and I am sure he said he could track drains as well.

 

[Relentless81]

Rang Dyno-Rod to get more info before and got told someone would call me back, guess what? No one called me back

Will try a different one tomorrow

 

[fastwunz]

If you don’t have any manholes or inspection chambers within the boundary of your property then I would be very surprised. You must have access to your drains in the event of an emergency. If there really is no access then an easement must be in place to allow you access onto the neighbouring land where the nearest inspection chamber is

 

[gc123]

If you don’t have any manholes or inspection chambers within the boundary of your property then I would be very surprised. You must have access to your drains in the event of an emergency. If there really is no access then an easement must be in place to allow you access onto the neighbouring land where the nearest inspection chamber is

i would have thought this maybe a previous owner has disguised the manhole or hidden it?

previous house many moons ago took me a while to find the manhole buried in the front garden under the turf about 12 inches down first owners wife apparently thought it was unsightly...though cant have been worse than the hole we dug

house we in now has manhole in the main road then a inspection chamber on the pavement that our nieghbours drains feed into then at least 2 others before our extension one th one at the bottom of the drive is about 8 foot deep been in it once to clear a blockage, i was a lot younger not nice when you realise the blockage is loose and its comming down the track......

 

[Borealis]

Some of the smaller drainage outfits are better than the big chain companies. After having the Thames Water contractors out 3 times, when something went wrong inside my soil stack, I got out a local outfit. They were extremely professional, helpful and sorted the issue for a very reasonable price.

I too would be surprised if there isn't a manhole somewhere. It's not unheard of for people to pave over or build on top of drains. My neighbour has a conservatory built over her inspection chamber...

 

[gc123]

we had a industrial unit once with the manhole in the middle of the customers reception hehehee

 

[Arcane]

We had a toilet put under the stairs as part of a refurb last year, caused more messing about than any other part of the project. The manhole cover was hidden under the kitchen floor and had to be moved, along with rerouting the drain etc. Absolute pain, the council were really strict about it and it added a couple of grand to the build cost.