Downpipe drainage

[Deerhound]

The drain for my front gutter downpipe is blocked right up to ground level, and the brick surround broken in half. I dug it out 6 inches or so and the mix of largish lumps of rock and brick in the soil makes it look like it was blocked deliberately. I have various health problems which make it hard for me to dig any further down myself.

There is no pooling of water in the front garden, except on top of the drain (see pic).

There is a water drain running under the house from the back which I assume this drain should be connected to.

Presumably I should get someone to see if they can clear it out? If that's not possible, what should I do? Stick an elbow on the bottom of the downpipe and run an extension 4m to the bottom of my front garden? Or put the extension right through a hole in my garden wall onto the pavement, to drain down into the street gutter (some houses in the area have done this but is it legal?)?

 

[Burnerman]

The first ploy has to be to find someone with some Marigolds and get stuck in there.......there's usually no problem reaching down to the bend and that's where most of the problems lie.
A wet vacuum cleaner can also play its part!
John

 

[Deerhound]

Thanks John.

I've now cleared it out with marigolds as far round the bend as I can reach. From what I can feel with my fingertips it still seems totally blocked with soil and rocks beyond that. What do you reckon?

 

[Burnerman]

Hopefully that gulley will terminate in a manhole fairly close by? I have to say, blockages as bad as this are a little unusual, so have you considered having your drain jetted?
John

 

[Deerhound]

I have no idea where the gulley terminates. No manhole obviously linked to it. I had a drain guy out today to clear it but he couldn't jet it without a manhole for access at the other end. He recommended getting the gully dug up and replaced for £750+VAT (+ a lot more if they find a faulty soakaway or pipe at the other end). Does that sound reasonable?

I'm pretty annoyed the surveyor missed this before I bought the house. I can't believe the problem is new in the past year.

 

[Burnerman]

I'm a little troubled that this problem hasn't been particularly noticed before.....the fact that there seems to be rubble after the gulley bend would indicate either a long term problem or a drain collapse.
Time for a little investigation perhaps, concerning an investigation onto neighbours property - it would be great to find out where the pipe actually runs to. If it heads to a soak away then there's no guarantee that it is any good now, and replacing the gulley alone will achieve nothing. If the gulley is heading for a soak away then there's no need to be another inspection chamber - feeling down the gulley will indicate the immediate direction that the pipe heads off to.
Have you looked for an inspection chamber lid, maybe covered up with garden by now?
It could be tempting to run the rainwater onto the pavement, but like you I don't know if it's legal - but it's common enough.
John

 

[Deerhound]

I've emailed the previous owners to see if they know what the system is.

The only liftable cover nearby is the one in the street for the water meter, diagonally across the front garden. I guess the rainwater drain could be connecting to that somewhere?

 

[Burnerman]

You're looking for a rectangular chamber cover maybe 2' x 18" ......so no connection there, I'm afraid!
I'd check in the gardens of the neighbouring properties if possible - it's possible that they are shared.
If your garden is small, it's unlikely to contain a soak away, but not impossible.
John

 

[Deerhound]

The previous owner replied:

"To be quite honest I don't really know for sure. I've got a feeling there might be a pipe that goes part way along and then soaks out. We took a really old plant out by the wall and fence which had to be dug quite deep and there was nothing there. It was always a little lumpy along the fence. It was never overly wet in that corner so maybe it goes straight down quite low?"

Not hugely useful! Better try the neighbours...

 

[Nige F]

I have no idea where the gulley terminates. No manhole obviously linked to it. I had a drain guy out today to clear it but he couldn't jet it without a manhole for access at the other end. He recommended getting the gully dug up and replaced for £750+VAT (+ a lot more if they find a faulty soakaway or pipe at the other end). Does that sound reasonable?

I'm pretty annoyed the surveyor missed this before I bought the house. I can't believe the problem is new in the past year.

That doesn't sound a reasonable price to me !! A day's work for a good groundworker and say, £70 for materials + vat if they are registered. Indeed more if problems @ the other end of the pipe.

 

[Deerhound]

An update...

I spoke to Thames Water today and they say there should be a connection to the main surface water drain in the street. They also told me which three other houses on my side of the street have a surface water drain connection. Interestingly, they all have downpipes which extend below ground level, whereas mine terminates just above the gully. Thames Water can't tell me where the relevant access manhole is though. I'm guessing it must be the one about 10 yards along the road, beyond a neighbour whose house doesn't have a connection to the main surface water drain.

I also spoke to another drain clearing guy. He said that if my gully is connected to the main surface water drain, he should be able to jet it from the house end even if there isn't a useful access manhole.

Finally, I've had my arm down the hole (now full of water) again. Not sure I learnt anything new but before I spend any more money I think I might wait until it's dried out and then (a) get a smaller hand tool down there to scrape away more of the blockage round the bend then (b) get my phone camera down there to have a look at it. Whatever the problem, it's been there for months if not years so a few more days shouldn't be the end of the world.

 

[Nige F]

Sounds like a good plan - let us know how you get on - it may be possible to make a hole in the top of the pipe after the gulley with a diamond holesaw for access IF it isn't encased in hard concrete.

 

[Burnerman]

May I be the first to award your 1000th thanks, Nige!
John

 

[Deerhound]

Rather than waiting for the gully to dry out, I got my spade out today and dug around the exit pipe.

As I'd started to suspect, the reason I couldn't dig to the end of the "blockage" with my hand was that the gully isn't connected to anything! There are just a few cracked remains of the bottom half of an old ceramic pipe coming from it. The water is being carried a foot or so from the wall in total.

So, looks like my options are:
1. Get the whole garden excavated to find the old connection to the Thames Water surface water drain and connect to it.
2. Get the whole garden excavated to install a proper soakaway.
3. Stick an elbow on the downpipe, add a horizontal section passing through new a hole in my front garden wall and drain onto the pavement.
4. Stick an elbow on the downpipe, add a horizontal section stopping short of the garden wall and drain into a new 30cm deep trench filled with gravel at the bottom of the garden. (Or put a gradually deepening trench up the side of the garden and put a waterproof lining on the first couple of metres.)
5. Do nothing

1 and 2 will be really expensive. 3 has been adopted by quite a few houses in the area (I did a bit of a survey this morning) and can look relatively neat if done professionally, but as previously discussed it's not ideal.

4 is my own (totally uninformed, probably stupid) idea for a cheaper, simpler, less effective soakaway. Sort of like a French drain without the pipe. Is that sort of thing ever done?

5 is tempting. The reasoning would be that the current situation has been there for at least a decade, possibly multiple decades, and the house has neither fallen down nor, as far as I can see, had any damp problems in that wall. We're on clay so I'm a bit wary of fixing the drain, having the soil dry out and contract, and seeing that side of my bay window subside. The bay windows in the area tend to have shallow foundations and you see a lot of brickwork repairs in them.

Thoughts much appreciated!

 

[Burnerman]

Just a thought about a soakaway....these only work if the soil is suitable, that is with minimal clay - and in any case its best to be away from the house.
With the rain volume we get these days, it would fill up very quickly!
Is it too much of a problem to continue digging, hopefully to find the remaining pipe?
Personally I'd consider (3) and say absolutely nothing (it was like this when I moved in, guv'nor) - in any case, I wouldn't want a blocked gulley soaking my house wall!
John