Drivereplacing concrete driveway

[Flotsam]

Thanks MSH, I have looked on the Interlay website for someone to quote on the driveway, but it seems like mainly block paving comps and no-one in Yorkshire. Would it be better just giving say your spec to 3 different contractors and getting them to quote on that? Some would say it is 'overkill'- The first guy who came out said two inches of concrete would be fine, but it needs to be four inches because of the weather.

Any forum users driveway experts in Leeds, West Yorkshire?

[msh paving]

the first guy who said 2in ,I would send him out of the gate with out asking any more questions MSH

[msh paving]

give 3 companys the spec,it a leval playing field that way,fair quotes then , and you judge the best one MSH

[Flotsam]

Thanks MSH,

I have had two quotes so far, based on their own spec., specifically 100mm concrete and 100mm type 1. I requested a brushed finish to the concrete.

Quote 1: Guy said he would include a slip (dpm?) which he stated stabilises the base,should any of it 'slump'. £40 per square metre. He said he had measured the driveway at 100 sq m, I measured it and it at no more than 70 sq m. Total quote incl. two steps £4500, no kerbing or edging, just shuttered. He also said drive could slope towards neighbours and a strip would be left between the neighbours block paving and my driveway which would be filled with pebbles and would act as a soakaway (not sure about that as th ground is clay).

Quote 2: Guy said dpm not needed. Driveway drainage would be facilitated by contouring the concrete so water would be channelled towards gulley dishes. Cost £8000.

Quote 3: Can't wait!

As a result of this, I have decide to produce my own spec:
(1) Driveway (area where car will be parked): 150mm concrete, 100mm MOT type1, dpm, A142 mesh installed 50mm below top of concrete.
(2) Driveway (part alongside house- foot traffic only): 100mm concrete, 100mm MOT type 1, dpm.
(3) Pathway across front of bay window: 100mm concrete, 100mm MOT type 1, dpm.
(4) Expansion gaps to be put in approx. every 3-4m. Filled with flexible filler board and 30mm silicone on top.
(5) Contraction gaps (needed? 25% thickness of concrete, placed where and filled? Not sure about these)
(6) Concrete to slope (crossfall) 1% towards house where a linear drain will be installed.
(7) Gap between linear dain and side of house to be filled with?
(8) 'Kerbing' to provide division between neighbour's and own drive.

Does this sound reasonable?

[lutonlagerlout]

I have never put DPM under a drive and have had no failures to date

when the type 1 is wacked hard its not impervious but it takes a while for the concrete to cure

mesh is a good idea for a drive and also a toe where the pavement meets the drive
the toe being maybe 300 mm by 300mm

we would normally use terram or similar under the type 1

cheers LLL

[GB_Groundworks]

you should always have dpm under concrete, im in sheffield but we are booked up for a few months

[Brucieboy]

^^^ Agreed. For an external slab, the dpm is not technically used for damp proof purposes but acts as a slip membrane to help minimise the occurrence of plastic shrinkage cracks. This is particularly important if hardcore containing crushed concrete, brick, block etc is used is as a sub-base (due to absorption sucking water out of the fresh concrete). It's less of a problem with Type 1 but still recommended.

[msh paving]

^^^ just what Giles said always DPM under concrete, stops water and grout loss no dry edges.makes it easier for concrete to flow.
Your spec sounds fine but i would omit the contraction joint
unless the kerb is above the concrete there is no point as the concrete will make its own edge
Forget the contouring concrete to the gully idea, cross fall to the channel drain.
£40 a metre is about right,
insist on the DPM for the sake of £40, will make a better job

MSH

[lutonlagerlout]

all new to me ^^^

i have seen plastic cracking on concrete over DPM on an over site so that theory doesnt hold 100%

DPM it is now from now on!

cheers LLL

[Brucieboy]

LLL - no dpm is only one factor that can cause plastic shrinkage cracking. The most common is lack of curing, particularly during hot, dry windy weather. It occurs when the rate of water evaporating at the surface exceeds the rate of bleeding. The cracks are generally evident within the first couple of hours after placing.

[lutonlagerlout]

yep saw it in an oversite we laid in july in the really hot weather

I grouted them in and all was fine after

cheers brucie

LLL

[Captain Concrete]

Membrane is NOT essential if you use concrete at a reasonable slump, the problem with membrane is all the bleed water has to come to the top (this can cause problems when finishing the concrete)
For your drive make sure the sub-base is well compacted, I would use 252 mesh, with 150mm of c35 concrete with a slump of S3 or 150. I would also want an expansion/contraction joint every 5m you can use these as a screed rail for your tamp. Make sure they vibrate it either with a vibrating tamp or poker, and brush finishing will be good just make sure they don't brush it too soon, it needs to start to set so the brush marks leave nice lines in the concrete. If you brush too soon (this is worse if you have a membrane) the bleed water and the brush will disturb the top and make it dusty. There are some good illustration on this site good luck AC http://www.proformconcrete.co.uk/index.htm

[lutonlagerlout]

nice information, is it your company Alvar and is there a dutch connection?
cheers LLL

[GB_Groundworks]

we've used these from burdens

http://www.kform.co.uk

similar product good for large bays and drives

[Captain Concrete]

hahahaha its a small world, going Dutch, K form is similar to Pro Form we find Pro form better because
1: The top rail is more secure
2: There is no horizontal hollow
3: its more competitively priced

Both are very good on large jobs but there are many small jobs it is also useful for as an example we know builders that use Proform in a traditional over site and concrete to finish floor level, saving cost and time, so also useful on small jobs too.