concrete to extend driveway

Jimmy_M

Hi
I've a front driveway i want to widen.
There's an area of grass beside it to widen into.
So i'm going to take .7m off the grass and fill it in with concrete.
Although there should be no need for the car to end up on the new concrete (its more to save us stepping into the muck) - it probably will end up having a wheel full of car on it now and again -

- so how deep should I go? (maybe i should go deeper for the first 1 or 2 hundred mm)
- what ratio should i use for the mix

The overall area im going to cover is .7m x 6m

Cheers.

seamus

Hah, that sounds exactly like what I'm going to do with my driveway. More a suggestion than assistance - my plan is to dig down around 100mm and place about 50/60mm of hardcore down on top of anti-weed fabric. Then I'll cover it with 40/50mm of decorative stone. Like you, the car wheels will end up on it now and again, but the car(s) will primarily live on the driveway that's already there.

My main rationale for doing it this way is that I prefer the look of the stones over concrete, and it means that I don't really need to worry all that much about drainage, subsidence or cracking as I would with concrete.

Jimmy_M

seamus wrote: »

Hah, that sounds exactly like what I'm going to do with my driveway. More a suggestion than assistance - my plan is to dig down around 100mm and place about 50/60mm of hardcore down on top of anti-weed fabric. Then I'll cover it with 40/50mm of decorative stone. Like you, the car wheels will end up on it now and again, but the car(s) will primarily live on the driveway that's already there.

My main rationale for doing it this way is that I prefer the look of the stones over concrete, and it means that I don't really need to worry all that much about drainage, subsidence or cracking as I would with concrete.

Fair enough... my use is purely functional and im not a fan of those stones they'll end up everywhere. we've no front wall and this will be our main thorofare in/out of the house so buggies bikes etc getting dragged through.... ill be the one sweeping them up - so concrete it is for me

Alun

Another thing with decorative stones is weeds ... I'm not talking about weeds coming up from underneath, weed membrane will theoretically sort that out.

As time goes by leaves from trees etc. drop onto it, and however hard you try they rot down to a mulch which provided a great place for weeds to grow from airborne seeds. You can use a leaf blower, but you'll always miss a few, especially if it's wet, which let's face it it usually is when leaves are falling.

Just a warning from someone who has a large area of such stones in his back garden. The only positive is that with the stones being quite loose, the weeds are easy to pull out

Luckysasha

Ideally dig out 12 inches or more if you need to hit solid ground. Lay in terram or Any weed cloth. throw in 4 inches of what's called "2 inch down stone" and whack the bejesus out of it. Top that with 4 inches of "804" and whack again. Top off with 4 inches of concrete about half a meter should do it if your getting ready mix. Mixing it yourself is not ideal as you won't get consistently throughout and it leads to a bad finish

Jimmy_M

Cheers for the replies - I dont think ill be getting it pumped - it sounds like too small a load. these may sound like stupid questions but
What volume is in e.g. a "ton bag" of hardcore or a "ton bag" of gravel. I assume theyre the same but may weigh a different amount - i.e. a ton bag is a ton bag no matter what you put in it.... if so my question is what volume is a ton bag?

When im buying gravel... is it mixed with sand? (i did a smaller concrete project before and i remember some confusion around this )

I see on brooksgroup website they sell a ton bag of "ready mix mortar" - i take it this is just mortar as is used for laying bricks and not what i want.

Luckysasha

I have heard it called "all in one aggregate" sand and stone mixed together. If you can get that then mix it 3 1/2 to 1 cement. If you have to buy separately mix it 2 stone , 1 sand to one cement. Oh and broadly speaking a tonne bag is a tonne weight

foxy farmer

A tonne of concreting gravel will produce around 0.5 cu m of concrete. Yes the bag will have a tonne of gravel in it or very close. 0.5m3 of concrete would do your job at a thickness of 100mm. This would be the minimum Id go on a slab like yours as its narrow and could be liable to crack. 6-8 bags of cement should be adequate.
Edit : Mix at ratio of 5:1 gravel to cement.

whizbang

In a few years time, you will probably be paying for the rainwater collected on concrete surfaces and directed into drains.
So think about using natural drainage if you can...