Diy help - Concrete removal and block laying

[DAVY]

I have a concrete drive ( ~100sqm) that I need to extend as my children get cars !.Rather than extend the concrete I am thinking about laying a new block paving drive. I am reasonable DIY confident but a job this size may take me a while.
So two questions at present.
How long will it take me to break up and remove 100 sq m of 6" concrete (hiring a breaker)?.any comments ?.
Secondly when laying block paving can the job be broken up into smaller areas somehow e.g by having fixed edges framing say 25 sq m so as to keep the job manageabe ? Any advice/ideas/comments gratefully received.

Davy

P.S excellent site

[dig dug dan]

Hire a hydraulic breaker (jcb Beaver). They are fairly cheap for a day, unless you use hss, and will work well. Just hope your exisitng concrete isn't re-inforced
Best thing to do though is break it up and leave it in a heap, dig out the drive to the depth, Hire a mini crusher,then crush the concrete and put it back in as sub-base. Might save you a bob or two
Not sure about your idea of doing it in sections. unless you are talking about doing all edge blocks first?

[DAVY]

thanks for reply...

For splitting the job into sections I was thinking along the lines of putting edge blocks in around each smaller section so that it can be done a bit at a time...would this work ?

[Tony McC]

100m² @ 150mm thick is 15m³, which is around 4 skips full of concrete. Using a proper jack-hammer, it will take you at least a couple of days just to break it up, and as long again to load it into skips or into a crusher. If you use one of the farty little 'drills' that you get from Hire Centres, double the amount of time needed to break out the concrete.

If you hire in a JCB with a pecker (hydraulic breaker), it will smash through the 100m² in half a day and load it all into skips, wagons or a crusher in an hour or two.

I know which I'd choose!

Breaking up the laying into separate bays is fine, as long as the intermediate restraint courses are firm and sound, but I'd go for 2 bays at 50m² rather than 4 @ 25m². In all honesty, once you done the breakout and excavation, and got the sub-base in place, laying the blocks is the easy bit and you should be able to lay the full 100m² over 2 or 3 weekends.

[DAVY]

Thanks for the info do far..I have been reading through all the archives and a possibility is to use put sand and blocks on top of the existing concrete.

DPC level is no problem as the drive does not meet the house brickwork. Loosk like I would need to mak some holes/channels in the concrete for drainage, although I guess if the blocks and joints are sealed most of the water should run down the drive. The fall we have is about 250mm over 20 meters which I guess is just about o.k ?
For the road end I would need to slope the raised bricks to road level, and looks like a 100mm drop over 2 m is recommended. Is another option to make a much steeper "ramp" (concrete or tarmac etc) at the road/drive interface i.e 100 mm drop over a foot or so (you can see I am trying to cur down the work on digging the concrete up !)
So all things considered I cannot see any major diasadvantage of blocking over the concrete or am i miising something ?

thanks again

DAVY

[Tony McC]

250mm over 20 meters is 1:80 which is about as flat as you dare go with block paving. Your levels and screeds wil need to be highly accurate to prevent any ponding.

I can't understand your plan at the "road end"; can you explain it again?

Laying over an existing concrete base is all well and good as long as you ensure the laying course material is properly drained. If it becomes saturated, you will get serious problems with channelisation.

Have you read the "Blocks over a base" page?

[DAVY]

Hi Tony,

Basically at the road end I just meant continue to block laying to within a foot or two of the road, (the blocks here will be about 100mm above the road level) and then just put a short sharp traingle ramp of concrete in to get from road to drive level....sorry if I am not explaining it to clearly.
Regarding the drainage If the blocks and gaps are sealed won;t this stop most water from reaching the concrete as it will run off the drive (down my not very steep incline !!)


Davy

[Tony McC]

Will you be allowed to pave right out to the road? Is there no public footpath or service strip?

One of the best, neatest and simplest threshold details involves using a kerb laid on its back. I'll post a photo tomorrow when I'm back on me other pooter.

Drainage - much of the surface water does run off (approx 98% on a 6+ month old drive laid to adequate falls) but some water will find its way into the bedding and so there must be some way to ensure it can get out of there.

[DAVY]

Tony, I live out in the sticks so no pavement, mains drainage, gas, buses etc --we do have a pub though !!

other option I am considering is to use a resin bound aggregate on top of the concrete and have read the archives on this. What about using bitumen emulsion as the "glue"...any idea of what that would cost and how effective it is ?

thanks

Davy

[Tony McC]

Bitumen as an adhesive is a thing of yesteryear. It was never very reliable, and with advent of polymer-modified biutmens and, in particular, resin bonding products, it's rarely used for anything other than low cost 'spray and chip' re-surfacing of existing highways. It's just not suitable nor economical for driveways.