Driveway Problem

[sheepinthefield]

Hey Folks

I've dug down around 150mm and found a clay drainage pipe from my neighbours house. Their house is a semi and sits at the end of the cul-de-sac and mine is also a semi and sits 45 degrees to hers.

Her house is higher so it explains why the clay pipe is in my garden.

I want to build a permiable driveway but with this clay pipe being basically where I start to lay the hardcore I'm worried about it breaking under vehicle loads

What is the right thing to do I've been told by two drainage people to just leave the pipe and protect it. So my thought was to cover it but steel is very very hard to manoeuvre.

Any other ideas

 

[Russanthonypowell]

are you saying clay pipe runs across your driveway (full width) or 45degrees across your driveway or even running down your driveway??
Depending on the levels and location of the pipe personally I would look to try and introduce a concrete bed and surround to the pipe, this could be done in stages as undermining too long a length it may collapse. have you a few pics??

 

[sheepinthefield]

So the pavement is 4 inches above the pipe on the right.. I'm thinking of making a reinforced concrete slab with a 20mm plate steel on top.

The pipe is now getting replaced with 100mm pvc... I'm thinking if cutting a 150mm pipe in half and putting it on top then filling the thing both sides with concrete and rebar.

 

[sheepinthefield]

There's no scope for making it lower as the storm drain in the street is basically horizontal to the pipe so there's no real additional room for making it fall further

 

[Russanthonypowell]

If the pipes getting replaced with UPVC then I would say install on a bed and surround of concrete. forget the 1/2 pipe and rebar thats not nessessary.

 

[sheepinthefield]

But the concrete is only 4 inch thick do you think it should be ok it's only a rain water gulley

 

[Russanthonypowell]

Just to be fully informed...Are you saying from top of pipe to finished surface it will be 100mm?? just talk me through this permeable drive design, I am beginning to think that you could replace with a perforated pipe to help your own driveway drainage.!!

 

[sheepinthefield]

So that pipe you see the top is 4 inches (100m) from the pavement level. The plan was to dig down 150 across the whole garden and put a membrane down and gravel with grids etc so that it would sit possibly 50mm above pavement with kerb edging.

That pipe is at the head of the drive at the entrance and theres no scope to move it as the storm drain it goes into is just beyond it on the turning circle so It would need even more work to lower it.

Currently ive a company going to dig out the clay and replace it with 110m plastic pipe.

And then my plan was to build two trenches where the slabs are in the picture. deeper and make two strips of concrete foundations to just above the pipe. Then put a 20mm thick steel plate across the void.

But some people just say to encase the plastic in concrete and it should be ok. But one fella put the fear in me when they said that a Truck might reverse into the drive so I've though about over-spec-ing it to be safe.

The pipe is a neighbours drain gulley. Their house is around 600mm higher than mine.

 

[sheepinthefield]

The driveway slopes from right to left so the pipe would be basically uphill from where the house is

 

[Nintendofan]

someone correct me if I'm wrong but if next door's drainage pipe runs over your land does that not make the owner of the pipe the local water company so you need permission off them to do anything with it?

 

[Russanthonypowell]

"So that pipe you see the top is 4 inches (100m) from the pavement level" The finished level of the driveway?" "The plan was to dig down 150 across the whole garden and put a membrane down" This need to be permeable membrane" "and gravel with grids""What do you mean by grids" etc so that it would sit possibly 50mm above pavement with kerb edging."please post a picture where you are standing back and the whole job can be assessed".

 

[sheepinthefield]

Pipe was never in the plans and has been there 70 years there's no easement. The pipe is clay and is already cracked in multiple spots. In Northern Ireland its a private drain pipe so not owned by the water company. And as its an 'upgrade' the neighbours arent complaining as they arent paying for it.

 

[sheepinthefield]

So in the bottom left you see the 'kerb' im going to fit around the edge. Its going to be 50mm above the pathway the whole way around.
The garden runs at a slope towards the house and towards the corner were that concrete 'kerb' is...

The top of the garden is where the pipe is... The top of it is 100mm below the pathway. In other words the bottom is 200mm deep.

I intend to use gravel grids they are plastic interlocking grids that gravel sits into. And the membrane will be non woven.

So to protect the pipe my first thought is to dig 150mm either side of the pipe to a depth of 350mm and backfill with hardcore 150mm... Then make two concrete strips either side of the pipe roughly 100-120mm high... and put A393 reinforcement mesh in the strips.

Then put a steel 20mm thick 400mm wide x foot long plate on top spanning the two strips. Then doing the gravel thing as normal.

Some people have said just to backfill around the pipe and put a renforced concrete pad and others said just cover the top of the pipe with a paving slab

 

[Russanthonypowell]

Now its clearer!! must say the ground conditions look a bit wet/soft, i take it pipe is crossing down by the trailer in the picture? as you say if you are renewing with plastic then there will be change to bed and surround with concrete, the drive will never see anything other than standard vehicles by the look of it.. shame youre not in mid wales I could give you a length of DI (ductile iron) 100mm couple of bandseals and you could drive a tank over it., yes to the geogrids and non woven terram, but do make sure youre formation as some strength to it, that ground looks like I would go up to my ankles if I walked across it!!

 

[sheepinthefield]

It's firm enough but it's clay even 2 feet deep so I'm probably fighting an uphill battle but the property near a 1-100 surface flood risk zone so I feel gravel at least makes it a huge retention tank for a period of time.

I can still try and order that I've been googling metal pipes and got stuff got Aircon but even that would help