laying concrete on a slope

[BrokenBiker]

need to lay some concrete on a slope for a drive. needs to look good and smooth as its not having anything put on top.

is it just a case of making a mix with a bit less water so its firmer? or just make the same mix as normal as its not going on a massive hill. well, it drops 4 foot over 18 foot, but im only concreting a section 2.4M wide by 4M long

all my mixes on flat ground have come out well, smooth off nicely and no cracking etc, never done a slope before though

 

[DrDeAtH]

You mixing yourself, or just getting it ready mixed and dumped in place?

 

[Rig Pig]

Put some steel mesh in or use glass reinforced to stop it cracking as the cars run over it.

 

[bigegg]

I'd use a bit firmer mix.
I have a 1in3 concreted slope - about 10ft square - which was done with a slightly drier mix.
rather than the final float off tho, I brushed across is with a yard brush to provide a rough surface for some grip in winter.

 

[mike os]

as above, or leave tamp marks in it across the slope

 

[premmington]

Anything you park a vehicle on needs mesh or rebar in it.

I have laid plenty of concrete in my time, but never on a slope.

Post a picture when it is done.

 

[bigegg]

Anything you park a vehicle on needs mesh or rebar in it.

I have laid plenty of concrete in my time, but never on a slope.

Post a picture when it is done.

My dad's garage has a slope down to it - about 12ft square, 1 in 6.
4in Poured straight on a 6in, hammer tamped brick rubble base - no reinforcimg. poured in 1975ish, still solid.
car driven over, and parked on EVERY day since then - cept for a fortnight a year when we're on holiday.

 

[Pete.]

I'd go for a low-slump mix and brush finish. If you rough finish it with a tamp it'll look horrid and might hold water in the ridges which will be deadly if it freezes. Damned if I'd be hand-mixing it though, at 200mm thick that's 2 cubes of concrete or 5 tons.

 

[BrokenBiker]

I will be using mesh as reinforcement. mixing myself in a mixer from bulk bags from wickes, they work out cheaper for me than the builders merchants, apparently the merchants round here don't like people like me doing a bit of everything under the term maintenance, they refuse to give me the same price they give their builders, so I go to wickes instead. customer is paying and not had one yet that said that sounds a bit steep. roofing place I went to the other day on the other hand was very keen to give me a good deal, think he needs the trade as it was dead when I went in.

anyway, have a 3inch sub base, with mesh and 4 inch of 4-2-1 agg sand and cement, its what I always use for drives, was recommended on here as a good all round ratio, and also the concrete calculator I used the first few times said the same. works well and not had any complaints. measure it all out in builders buckets to keep it all consistent.

haven't started the job yet, wont be till week after next depending on weather, have a little digger on hire from a mate to get the hole sorted. starting to get fed up with digging big holes by hand. one thing is for sure I have made plenty of friends with plenty of toys for hire

 

[Sidewinder]

I've laid over 100t of concrete in my time, and a lot on slopes, personally I would split it into two bays, and shutter up.
A brushed finish is nicer.
Yes a stiff mix.
Watch for frost.
The mesh must be 1/3 up from the bottom of the concrete mix for maximum strength.
For cars, there is no need for reinforcement for a 150mm depth of concrete.
@ 100mm you may need reinforcement.
Ensure the sub-base is well compacted, whacker at least, vibrating rolls better.
HTH

 

[BrokenBiker]

I've laid over 100t of concrete in my time, and a lot on slopes, personally I would split it into two bays, and shutter up.
A brushed finish is nicer.
Yes a stiff mix.
Watch for frost.
The mesh must be 1/3 up from the bottom of the concrete mix for maximum strength.
For cars, there is no need for reinforcement for a 150mm depth of concrete.
@ 100mm you may need reinforcement.
Ensure the sub-base is well compacted, whacker at least, vibrating rolls better.
HTH

when you say watch for frost do you mean the frost as in cold weather, or is it a term I don't know about?

also I buy the sub base in bags, pour and rake it flat and even, then I have a bit of re-bar about 4ft long with a square welded on the bottom and a 5kg weight on it, use that to compact it all down. it seems to work well, takes a bit of effort but was made from scrap I found in a site skip on another job so cost nothing. seems to work as intended, obviously not to the standard of a whacker though

 

[Rig Pig]

If the water in uncured concrete freezes it wrecks the job! On a different note did you see the link to the Boxford lathe for sale?

 

[BrokenBiker]

If the water in uncured concrete freezes it wrecks the job! On a different note did you see the link to the Boxford lathe for sale?

ah right, yes I knew about that just didn't put the 2 together as frost. and no didn't see the boxford? not sure I have space for a big lathe, have you a link?

 

[Sidewinder]

Yes BB, I meant freezing frost, it's heading toward that time of year now.
Sorry.
You can get frost proofer for the mix, any remote chance of frost stick it in, it won't do any harm

 

[Rig Pig]

It's in a thread called Myford ml7 lathe on here, don't know how to link to it.

 

[BrokenBiker]

ok cheers, will search it

 

[BrokenBiker]

It's in a thread called Myford ml7 lathe on here, don't know how to link to it.

cant seem to find it, can you copy and paste the url?

Yes BB, I meant freezing frost, it's heading toward that time of year now.
Sorry.
You can get frost proofer for the mix, any remote chance of frost stick it in, it won't do any harm

will see what the forecast is, I know its getting bloody cold in the mornings, was shocked when I went out at 5 this morning, quite deceiving getting up with the heating on

 

[Sidewinder]

It is BB, I was cold going out @ 7:15!
Heated seat in the van on!!!

 

[BrokenBiker]

I cranked the heating up to 27, de-mist on, heated seat on. by the time I hit the motorway I had to set AC to 15 as I was sweating my Bo****ks off what with having a big thick hi viz bomber jacket and thermals on (no heating in the factory)

 

[Sidewinder]

I cranked the heating up to 27, de-mist on, heated seat on. by the time I hit the motorway I had to set AC to 15 as I was sweating my Bo****ks off what with having a big thick hi viz bomber jacket and thermals on (no heating in the factory)

I thought you were working in an automotive machining place, ISO9001 & all that?
If so, how can you not have the factory @ a stwble temperature?
I could well be wrong. See Mrs. SW for details.
I HATE wearing even a jacket when driving.
I normally only wear a T shirt at most times all year round, unless it is really cold.
Then I may put 2 T shirts on, one thermal, if it is stupidly cold & I am working outside then I will put some additional gear on.
I have a reasonable layer of personal insulation IYKWIM!