Water, springs, tarmac

[RogerS]

Our drive goes down a steep hill, currently stoned . Well, I use the term loosely as successive winter storms have carried all the loose stuff down the hill. We've restoned once already and it's a bit like burning £50 notes for all the durability. So we're biting the bullet and getting it tarmacced by Tarmac. Got the quote...gulp..but needs to be done.

Question...at the top of the drive, rainwater from further up the hill (could even be coming from the Malvern Hills) trickles out of the ground and runs down the drive. If some more base core stone goes on top followed by tarmac, will this be OK? I'll be asking Tarmac but I'd appreciate your views first.

Guess I should start bottling the water to pay for the tarmac :?

 

[Fecn]

Tarmac is a porous surface. When they lay the tarmac, they should lay 10-12" of hardcore (big gravel) underneath it to make the ground stable and to deal with any drainage issues... and once the tarmac's poured and rolled on top, the hardcore underneath will be pretty well locked into place.

You could have a river running under the drive and never know it.

 

[CHJ]

Roger, If there is a tendency to any springs under your driveway then unless you have a significant Drainage layer of hardcore then any heavy frost may lift the Tarmac.

The lane immediately near my place suffers from this every winter but of course the correct remedy of providing an alternate channel for the springs is never done, just patched on the surface every couple of months.

Also make sure that surface water at the top of the drive is channeled to the side so that you don't get a skating rink layed down in the winter.

 

[Slim]

I would suggest getting Tarmac to install a gulley across the end of your drive. This will catch the water which can then be diverted down the hill into a drain or soak away.

I am a landscaper and have experienced a problem like this before. The method I described sorted it.

 

[RogerS]

Mmm..thanks guys. I think I'll get the rep back and discuss it a bit further.

We're already putting a gulley in but that is right at the bottom of the hill. The spring (for want of a better word) comes out at the top of the hill.

I like the idea that the water will run away underneath the tarmac but not that it might lift with frost.

 

[Shultzy]

Roger, look on this site for info on what should be laid

http://www.pavingexpert.com/tarmac02.htm

You should be ok with Tarmac, a reputable company, others aren't so careful in what they lay. Might be best to lay a land drain to capture any water heading for the drive.

 

[RogerS]

Thanks, Shultzy, for an interesting link.

Take your point re the land drain but the water weeps out part way down the hill. Funny you should mention the land-drain as that is what I laid down out the back of the house (you can see the area in my avatar).

We actually have water weeping out in two locations and I laid a small drainage channel across the drive close to the house and diverted the water into the adjacent field for the first location.

The second location is the one mentioned at the start of the thread. Guess we could put some sort of land drain in but, to be honest, the sub-base is going to act like a very wide land drain in itself, I think.

 

[Shultzy]

If it gets into the sub-base how is it going to get out again. Remember when water freezes it expands, you don't want it doing that at the botttom of the driveway.

 

[RogerS]

That's a very, very good point Shultzy. Will ask Tarmac.

 

[RogerS]

The boys from Tarmac have done an excellent job and with all the rain, it was great to see all the water cascading from the field into the drainage ditch and down the huge drainpipes and into the brook. The bottom corner is no longer a quagmire.

But...I notice that the tarmac at the top of the hill and near our house, is weeping water from the small spring that I referred to. Not too happy about this as what comes out can also go in, thinking heavy frosts/frost heave etc as suggested by others.

So...awaiting Tarmacs response

 

[woodbutcher]

hi roger


i'm sorry to hear that you are having problems already.

when tarmac did the groundwork for your drive they should have put a dutch drain in where the spring is to channel the water away from under the drive if not the water will wash away your sub base which will cause subsidence ask them to come back and rectify it immediately ad don't take no for an answer.



woodbutcher