A bit of a mystery with my purchase - can't find drains!

deeboy12

I wonder if anyone has some advice (or even better, personal experience) they can share, relating to something that's come up in the (otherwise quick and smooth) conveyancing process?!

My building surveyor has advised that, prior to exchange of contracts, I should arrange a CCTV survey of the foul and rainwater underground drainage of my circa 1900 terraced house purchase.

The water search says that the property connects directly to a public foul sewer which is within the boundaries of the property. But on my second viewing, I and the estate agent both looked for an inspection chamber (manhole cover) in the back garden and couldn’t find one. 

The owner has since responded to say that he doesn't know where it is. There are no extensions so hasn't been built over, but in the rear garden there is both a large cement patio area, and a side return lean-to which I wasn't fully able to explore due to the tenant's possessions in there (it's an extended family member who's moving out shortly).

My question is, how much of an issue is this - and is it a deal-breaker? In case relevant, one of my absolute musts is that I want to add a downstairs loo.

And my thinking so far is to go back and:

1. Ask the owner (in practice, the tenant) to uncover the floor area of the lean-to and see if it's there.

2. Ask the owner if he'd be willing to share relevant findings of his own survey/ conveyancing process from his own purchase in 2016 (as it's quite recent).

3. If the above fail, ask my conveyancer to go back to the water board and enquire whether they have a map/ knowledge of the drain arrangements (doing this will obviously add to my conveyancing costs but may not uncover the info needed)

4. If all that doesn't work, accept the risk and move on with the purchase, and assume I can still add a downstairs loo.

Any thoughts/ advice much appreciated

Soot2006

I bet it's under the patio!

I have one inspection chamber under my conservatory and another under my extension. Both added in the days when people just went ahead with such things. Mostly, I cross my fingers and hope ...

Section62

deeboy12 said:

My question is, how much of an issue is this - and is it a deal-breaker? In case relevant, one of my absolute musts is that I want to add a downstairs loo.

For me it would be a dealbreaker if I wasn't able to establish how the fould drainage arrangements worked if I already knew that I needed to add a downstairs toilet.  Although there are options using a macerator, you will still need to be able to make a connection to foul drainage somewhere.

deeboy12 said:

1. Ask the owner (in practice, the tenant) to uncover the floor area of the lean-to and see if it's there.

I'd do this^.

However, not all properties are connected to foul drainage via a manhole - you could just have a branch or "saddle" connection to the main sewer.  A CCTV survey of the main sewer would confirm.

deeboy12 said:

3. If the above fail, ask my conveyancer to go back to the water board and enquire whether they have a map/ knowledge of the drain arrangements (doing this will obviously add to my conveyancing costs but may not uncover the info needed)

You might have more luck seeing whether the council's building control department have plans for this property or any of the near neighbours.

Local water companies have very limited mapping of non-main drainage, even those that are/were Section 36 properties.  The water company's plans may show the main line, but not your connection(s) to it.

Be aware that if the pipe is a public sewer, you'll need consent of the water company to make an additional connection to it for the downstairs toilet.

deeboy12

Section62 said:

deeboy12 said:

My question is, how much of an issue is this - and is it a deal-breaker? In case relevant, one of my absolute musts is that I want to add a downstairs loo.

For me it would be a dealbreaker if I wasn't able to establish how the fould drainage arrangements worked if I already knew that I needed to add a downstairs toilet.  Although there are options using a macerator, you will still need to be able to make a connection to foul drainage somewhere.

deeboy12 said:

1. Ask the owner (in practice, the tenant) to uncover the floor area of the lean-to and see if it's there.

I'd do this^.

However, not all properties are connected to foul drainage via a manhole - you could just have a branch or "saddle" connection to the main sewer.  A CCTV survey of the main sewer would confirm.

Thank you - this is helpful.

It sounds like I do need to look at this rigorously then as the loo is a must.

To your comment 'A CCTV survey of the main sewer would confirm' - what I think you're saying is that it's possible I don't have a manhole even though I do apparently have a public foul sewer on the property? And to do a CCTV survey we would (still) need to find the manhole that the property does connect to (e.g. in a neighbour's garden) - is that correct?

Section62

deeboy12 said:

To your comment 'A CCTV survey of the main sewer would confirm' - what I think you're saying is that it's possible I don't have a manhole even though I do apparently have a public foul sewer on the property? And to do a CCTV survey we would (still) need to find the manhole that the property does connect to (e.g. in a neighbour's garden) - is that correct?

Yes, exactly that.  It is possible you have a main (or large Section 36) sewer running through the property and your connection is made to it without a manhole.

Doing a CCTV survey of that (main) pipe would show whether there were connection(s) into it within the length in your property.  A toilet flush test, or a dye test, could then be used to confirm which connection it is if there is any remaining doubt.

FreeBear

Have a look over the fences either side and/or chat with the neighbours to see if/where their man hole covers are. A fairly good chance that yours would be located in a similar spot.

canaldumidi

A metal coathanger, cutoff and bent into a U shape makes a good divining rod. I've found drains this way....

ProDave

Serious suggestion.  Dowsing rods, and trace the run of the drains (turn a tap on so water is running down the drain)

Slithery

canaldumidi said:

A metal coathanger, cutoff and bent into a U shape makes a good diving rod.....

I really hope that you meant 'divining'. I wouldn't want to go swimming in a sewer even if I did fit.

deeboy12

Section62 said:

deeboy12 said:

To your comment 'A CCTV survey of the main sewer would confirm' - what I think you're saying is that it's possible I don't have a manhole even though I do apparently have a public foul sewer on the property? And to do a CCTV survey we would (still) need to find the manhole that the property does connect to (e.g. in a neighbour's garden) - is that correct?

Yes, exactly that.  It is possible you have a main (or large Section 36) sewer running through the property and your connection is made to it without a manhole.

Doing a CCTV survey of that (main) pipe would show whether there were connection(s) into it within the length in your property.  A toilet flush test, or a dye test, could then be used to confirm which connection it is if there is any remaining doubt.

Thank you!

deeboy12

FreeBear said:

Have a look over the fences either side and/or chat with the neighbours to see if/where their man hole covers are. A fairly good chance that yours would be located in a similar spot.

Yes, I think I'll do just that!