Would you be worried about this gap down side of drain?

WorriedWill

Our driveway slopes towards our house, so theres an aco drain along the side wall of the house. However, there's a good inch or so gap between the drive and the drain. It only struck me the other day that this gap probably renders the drain useless. We've lived here 8 years and the gap has always been there, but I'm suddenly worried about where the water must run when it rains (well... down the gap). I am tempted to get the hole filled up before it causes subsidence, but equally concerned about changing anything after it being that way for so long with no problems. Is it really so different to rain soaking into the flower beds along the front of our house, and what if it has the opposite effect and causes heave when the clay soil dries out underneath? Is it just there to prevent standing water against the house (in which case it's doing the job fine)? Would be very grateful for some advice before I get someone to sort it, and potentially create a new problem where there isn't one at the moment. House is about 25 years old if that makes a difference.

Thanks so much

Davesnave

It would take a hell of a volume of water to erode enough material to cause subsidence on a house with footings a metre deep!

The truth is probably that it makes no difference either way whether the water goes to the Acco drain and thus to a soak-away, or directly into the soil. It may even do both in heavy rain, if the gap fills up and the Acco takes the surplus.

Heave is something related to the status quo being upset when trees are removed that formerly took water from the soil and transpired it into the atmosphere. As you surmise, wherever the water goes, things will probably stay pretty much the same below the surface.

If it were me, I wouldn't 'get someone in,' I'd probably fill the gap with a dryish, weak, mortar mix, tamp it down, tidy up and forget about it.

WorriedWill

Thank you Davesnave that's reassuring. I guess I was thinking along the lines of what can happen when a leaking drain causes subsidence over a number of years. I like your idea about the mortar mix, just a little nervous in case the drain alone can't cope with the additional water that would make its way in and end up flooding. Am I worrying too much??

Murmansk

Fill that gap!

Davesnave

Well, I don't know where the Acco drain goes, so it's difficult to advise. Theoretically, it should go to a soak-away about 5m from the house, but sometimes people routed roof and surface water into the sewer, which was wrong, but not a problem at an individual level.


I would assume it goes to a soak-away in the garden. It's not likely to cause any problems anyway. I had a soak away (now replaced) under my old conservatory and never knew about it till I demolished the thing.

WorriedWill

Thank you. It connects up to a drain on the pavement out the front of my house, so I presume it goes into the the sewage system.

societys_child

Have tried running a hosepipe into the drain for a few minutes, see if the water runs away without backing up?


Does sound like the gap should be filled.

WorriedWill

Thanks for the replies, the hose idea is a good shout. I am getting really stressed out about it and wish I'd never noticed now. Ever since I started thinking about it I've been waking up every morning full of worry. I just feel like the house could end up with big problems if I don't fix it but also if I do. I feel quite sick about it and am thinking about selling up, even though I wasn't planning to move for 10 years+! The worry is made worse by the fact that the floor level inside the house is actually lower than the driveway and the drain (due to being built on a slope). . Not a well built house really

Davesnave

From an outsider's viewpoint your fears appear irrational, and your possible solution of moving out, even more so. A move could easily cost £10k upwards, and if you are this easily spooked, how can you be sure that the next property will be any less worrisome?


If you have doubts remaining, get a surveyor registered with RICS to look at the areas of concern and report . This will be cheaper than moving. Even if some problem were found, you'd at least get a resolution and save yourself a lot of bother.

Personally, I'd take physical problems with a building over problems with neighbours any day. Physical problems have a straightforward resolution. When you move, the neighbours are a wild card!

WorriedWill

Thank you Davesnave, it reassures me that I am probably being irrational rather than it being a genuinely huge problem. My girlfriend is pregnant with our first child and I guess I'm going into overdrive making sure that everything's secure for us and the new baby. Can these problems ever cost upwards of 10k? We do have savings if need be, and yes would rather spend it on staying here really. I just know that sometimes people can spend a fortune trying to fix things, but end up making them worse and getting nowhere with no money left. If it's going to be like that then I'd rather sell up for a bit less than market value and let someone fix it who knows what they're doing! I take some comfort in the fact that nothing came up in the survey when I bought the house, but then again it was only a homebuyers...

markin

The driveway would sink before the house, if its not moved in 10ys its fine.