Sub base/temp drive material

[Vijay]

I need to get down some sort of hard standing surface for the concrete lorries to drive up on so I'm wondering what would be sensible to use. I realise it will get ruined but what I'm thinking is it might act as a pre-sub base (so under the sub base) for my block paving?

 

For anyone who's had to do this, what material did you use and what sort of thickness? Maybe crushed concrete or road planings?

 

Cheers

 

Vijay

[Pete]

Road planings is ideal. Does not hold water and is quite cheap.

[Vijay]

Cheers Pete. Any idea what sort of thickness I would need?

[dogman]

Make sure its from a good supplier. last lot i bought had so much glass in it it was useless. The load before that was like new tarmac and has hardened like a road

[ProDave]

300mm of MOT1 and 50mm of base layer tarmac.  I expected this to get trashed by all the delivery lorries, concrete lorries etc, but it hardly touched it and eventually I will just put the top layer of tarmac onto it.

[Mr Punter]

Depends on your soil and where you are located.  Crushed concrete is normally cheap.  If the sub soil is crappy, strip topsoil then try a layer of terram, then 300mm crushed. If your groundworker or aggregate supplier is local they will best advise.

[Oz07]

30-70 clean. Type 3 I think

200mm thick and leave around 100mm low not including surfacing. +75mm tarmac. Top the 100mm up with type 1 towards end of build. 

[Pete]

Depends on your soil. As other's have said, remove topsoil and lay terram. Average depth of planings was 7" and I have had 20 ton wagon on it and it has not moved a bit.

[TerryE]

23 hours ago, Pete said:

Road planings is ideal. Does not hold water and is quite cheap.

 

Whilst I agree with Pete's comment and used planings for our temporary (and which later became our permanent base for our driveway), there is one caveat: if you are going to remove it later, this might be quite expensive because it won't be treated as hardcore and it will have to go a registered dump if you can't find someone who will take it.

[Vijay]

Thanks Chaps.

 

I think we have crossed wires in some posts though. I will be having block paving as a finish, so I'm looking to put something as cheap as possible that will be a layer under the sub base for the blocks paving. I believe the buildup for block paving is approx 200mm (from the paving expert site), so I thought it best to lay a cheap hardstanding that I don't really care if it gets broken up or crushed down etc. UNDER the 200mm block paving.

 

So, I dig down 400mm from FGL and lay 200mm of road planings/crushed concrete/anything else if cheaper. This may get damaged with concrete lorries etc. At a later date when I'm ready to do my drive, I lay down a geo-textile membrane on top of the 200mm sacrificed layer, then 100mm sub base, then 40mm bedding then pavers. How does that sound?

 

Vijay

Edited March 12, 2017 by Vijay

[Vijay]

Or would the 100mm of paving sub base work as a temporary drive? I know it would get damaged by vehicles but then I could just top up the base again. Would that work and probably be cheaper in the long run??????

[Vijay]

Reading more, going for 150mm  type 1 sub base seems to be the best for a block paved drive. Anyone have any idea how well 150mm of type 1 would stand up to concrete lorries?

[Jeremy Harris]

If you're going for permeable pavers, then don't use MOT1, as it's not very permeable at all, use MOT3, or crushed concrete, or something similar that is permeable.

[Vijay]

Yeah that's what I read on the pavingexpert site and why I asked about permeable

[Triassic]

Permeability is all to do with pore size, i.e. the space between the lumps of fill, the larger the lumps the larger the pore size. So if you use a sub-base with lots of fine material it won't be very permeable.

 

one option would be to use crushed concrete as the sub-base, let that get trashed by the vehicles. Once your ready for the finished drive, lay a drainage layer over it and then place the block drive.

 

Section 5 has some good information 

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/7728/pavingfrontgardens.pdf

Edited March 12, 2017 by Triassic

[Russell griffiths]

If going for crushed concrete you need to be quite specific as to what its content is. 

I have just had a load tipped and 90% was crushed brick after a rough level with the digger and a bit of rain it has turned into red coloured porridge. 

I stopped the other trucks coming and looked for a different supplier. 

It was £10 ton which is fairly reasonable but no good if it turns to custard after a drop of rain. 

[TerryE]

Vijay, one thing to be aware of is the height of the water table and the soil type. 200mm hardcore on its own won't take heavy lorries if the underlying soil liquifies.  This will a spread the top load and help to minimise wheel damage but you need something solid underneath.  We have a firm clay 2 miles down the road.  This will take really heavy loads if it is drained and free from surface water, but once wet, it looks like the brick clay in Ed's barrow.

 

You might need to put in land drainage either side of the line that the lorries will use, and drain / pump this.  OR used a lot more temporary subbase.

[joe90]

As a slight aside to this thread, I have a patio area that has to be raised 400-500mmand the ground is dry and drained, I have about 75 tons of clay that was dug out of the foundations and has been piled high and quite dry. I am tempted to use the clay to raise this level and save me ££££s in stone. The patio slabs will stop water getting into the clay so I think it will stay stable, what do you guys think?

[Crofter]

16 minutes ago, joe90 said:

As a slight aside to this thread, I have a patio area that has to be raised 400-500mmand the ground is dry and drained, I have about 75 tons of clay that was dug out of the foundations and has been piled high and quite dry. I am tempted to use the clay to raise this level and save me ££££s in stone. The patio slabs will stop water getting into the clay so I think it will stay stable, what do you guys think?

 

I can see why you're tempted, but how are the patio slabs going to create a waterproof seal? You'd have to lay an impermeable membrane under them as the joints between the slabs will always let some water through.

As you probably know, clay is notorious for swelling and shrinking according to moisture content. So any water getting past your slabs, or rising up from below, is going to upset your nice level patio and open up the gaps between the slabs even more, making things worse.

[Vijay]

10 hours ago, TerryE said:

Vijay, one thing to be aware of is the height of the water table and the soil type. 200mm hardcore on its own won't take heavy lorries if the underlying soil liquifies.  This will a spread the top load and help to minimise wheel damage but you need something solid underneath.  We have a firm clay 2 miles down the road.  This will take really heavy loads if it is drained and free from surface water, but once wet, it looks like the brick clay in Ed's barrow.

 

You might need to put in land drainage either side of the line that the lorries will use, and drain / pump this.  OR used a lot more temporary subbase.

Cheers Terry. I'm thinking permeable paving isn't the way to go anyway from reading various links others have posted. I'm waiting to hear what drainage the access drive will have (if any) but I think a drain at the front of the drive into either a soakaway or a harvesting tank makes more sense. So I'm still leaning towards type 1 and then top up at a future date

[TerryE]

Why don't come over one w/e and we can chat about this? Or I visit Roade.

[Vijay]

Hi Terry, that would be fantastic. I can't do this one coming but maybe the following if you're free?

[TerryE]

You've my email.  I think that we're free, but I better double-check with the boss I will ping you a confirmation.

[Russdl]

Just reviving this thread as it's sort of relevant for us.

 

We are going to have a turning circle for the fire brigade on our plot (wether we like it or not) and the hatched area on the drawing below is what has been accepted by BCO. It will of course be very useful in permitting lorries to turn around during our build as the the narrow access track will preclude lorries turning anywhere else or reversing out. My plan at the moment is:

 

1.  Put down a sub base that will take the construction traffic.

2.  Once major construction is finished, dig up what is required in order to lay the drains.

3.  Top up with 150mm Type 1.

4.  Finish off the drive with 40mm of gravel in a stabilisation grid.

 

What have I missed? Also:

 

a) Any problems with my plan/order of doing things?

b) How deep should I make the sub base for the construction traffic (were are on chalk after digging down a wee bit)?

c) On the drawing it says that the driveway should have a minimum carrying capacity of 12.5 tonnes, how do I know if I've achieved that?

 

 

[Ferdinand]

Not sure if relevant, however if you did your drains first you could plumb your welfare hut in temporarily and save on weekly suck-out for the loo. Would also reduce traffic.

Edited February 19, 2019 by Ferdinand