Rainwater drain problems

[thetcutkid]

Apologises for the long post but I thought a bit of background and what we’ve done so far might help.

I live in a 1930’s semi-detached house and we’ve got problems with a rainwater drain at the front of the house which is fed by a down pipe from the gutters.

The drain is situated on the side of the house supposedly unattached to my neighbour, however, about 40 years ago, our then neighbour asked my dad whether he’d mind if they built a lightweight roof between the outside walls of our two houses so he could have a car port (for want of a better expression). My dad, being a non-confrontational sort of bloke, said he could and over the years, through many changes of owner, this ‘car port’ has now turned into a fully fledged garage, with a heavy duty, timber structured, felted roof and roller shutter.

The problem is, the two rain water drains on the corner of each of our properties are both within the garage space, about a foot inside the shutter and ours is blocked so that during heavy rain it completely floods our neighbours ‘garage’.

My neighbours drain is clear, water runs away freely and it doesn’t overflow.

Now without getting into the rights and wrongs of the existence this garage, after the last couple of weeks of cloud bursts, my neighbour has asked whether we can have our drain looked at as he’s having to put things in the garage up on pallets to keep them dry.

So our first port of call was Thames Water who said they’d come out for free but depending on what was found, we may be charged to get it fixed. When they came the guy tried plunging and then jetting the drain but he couldn’t clear it. He then opened the nearest manhole (which was actually in my neighbours drive) and put a camera down to try and see where these two rain water drains fed into the public drains. I was with him all the time and looking at the screen and at no point could we see inlets into the main drain.

Even with the various maps/plans he had with him, he was at a total loss as to where they went.

He said that he’d get a ‘network engineer’ to come out and he could investigate where these drains went to....needless to say a week later he’s still not arrived and on phoning Thames Water this morning the job has been closed as apparently “...we were advised to call in a private company to investigate as all Thames Water drains were running clear...” - this advice was news to me.

I’ve been warned off DynoRod by builders and Thames Water alike as total rip-off merchants, so I’m really unsure of finding a reputable company and don’t know the best way to proceed - apologises, I also have several questions.

1) Could it be that these are soakaway drains, this would, I assume, explain why there is no apparent feed into the nearest main drain ?

2) If they are soakaways, why is it my neighbours doesn’t flood - can they become blocked and how do you clear them ?

3) How exactly does a soakaway drain work and how would they have been constructed on a 1930’s house ?

4) Both houses have block paved drives, is it likely that these will have to come up in order to locate the soakaway ?

5) If these are not soakaway drains, how do we find where they go - the Thames Water guy tried to use a dye but the drain is so blocked it just came back into the garage.

Any thoughts, advice, recommends would be really appreciated because we’re a little worried we could be landed with a whopping bill if the drives have to come up.

Many thanks for reading.

Nick

 

[LanceCorpralJones]

1) Could it be that these are soakaway drains, this would, I assume, explain why there is no apparent feed into the nearest main drain ?

Very possibly. When were the drains installed? Recent requirements for most LAs require new rain water drains to go to soakaways.

2) If they are soakaways, why is it my neighbours doesn’t flood - can they become blocked and how do you clear them ?

A soakaway is just a big hole filled with rubble, bricks, etc. If no membrane was used to suround the soakaway, dirt, mud, other fine particles can fill the voids thereby reducing the capacity of the soakaway. The capacity of a soakaway is always guesswork anyway unless the modern crate type systems are used.

3) How exactly does a soakaway drain work and how would they have been constructed on a 1930’s house ?

Google soakaway. There was a brilliant website showing how to construct a soakaway, but I can't remember the link now.
The age of the house is irrelevant. The type and consisitency of the ground is more important.

4) Both houses have block paved drives, is it likely that these will have to come up in order to locate the soakaway ?

Depends if/where the soakaway is located. The soakaway should have been located at least 5 metres from any building if my memoey serves me well. It's unlikely that two soakaways would have been used if they were done at the same time.

5) If these are not soakaway drains, how do we find where they go - the Thames Water guy tried to use a dye but the drain is so blocked it just came back into the garage.

Have you tried dye in your neighbour's drain? Have you tried determining the direction of the outlet?
Are yours and your neighbour's drains at the same level? If the soakaway is full and yours is lower it is possible that yours will flood but your neighbour's will appear clear.

Finally, it's higly unlikely that your drain will be on your neighbour's land. So your neighbour has built the garage over your drain/land. They should move their garage. Check the boundaries.

 

[thetcutkid]

Many thanks for your reply LanceCorpralJones.

The drains are original and, as far as my mum can remember, have never been looked at - they are at exactly the same height, opposite each other, a garage door width apart.

Good shout about dying his drain, wish I'd suggested that when the Thames Water guy was here.

 

[theprinceofdarkness]

When I lived in a 1934 semi, there shared drive which led to garages in both gardens, so on this basis I would think that to build a soak away under a drive would require it to support the weight of a car as designed. So I would think that the houses had individual soak away under their front gardens.
If you put your hand down your drain (which should be salt glaze piping), a, you can unblock the trap and b, determine in which direction the drain is pointing.
I would regularise the status of your neighbour's garage or the next thing will be them drilling holes in your wall to fix shelving and how do you maintain that side of the house - gutters etc?
Frank

 

[thetcutkid]

Thanks for your reply Frank and I totally agree....the problem is that it's difficult for us to moan at this guy (or any of the last few owners) when they've bought the house with the garage already in being.

The house is (or rather would be, without this garage) a shared drive to garages behind (although our garage is long gone), my neighbour even has the original garage behind this 'temporary' one !

When the gutters are cleared etc. we have to ask for permission to go up on the roof of this thing and put a ladder up.

The open part of the drain I put my hand down won't be very deep then, I should be able to feel the bottom ?

 

[theprinceofdarkness]

They are normally 12-15", roll your sleeves up!. The typical shape is a deformed S lying on its back, so you arm is going down one leg, with the U bend at the bottom, where it then rises, goes over the top then normally straight down at a low angle (30 degrees?). Once you put your hand in it you can feel which way the U bend is pointing. It would be extremely eccentric of the builder if it was not pointing towards the actual sewer/soak away (only perhaps looping around the actual building).
Frank