High curb and concrete, but which one is recommended?

Hi,

we want to order our paving stones and terrace slabs today and complete everything this year.

We are using a 6x20/25x100 deep curb stone for the access paths, the splash protection (30cm wide filled with gravel), and the terrace. At least, that's the plan.

And for the driveway, an 8 deep curb stone.

In total, it's about 70m of deep curb stones.
My wife's uncle, who is helping us and works in road construction at the city, said it's enough to set only the joints in concrete.
I am rather skeptical about that.

What do you say, how much concrete do we roughly need if we want to do it properly?
And which concrete exactly should be used?
Cement concrete, screed concrete, mortar, rapid concrete?

Are these 30kg bags made for that?

Thanks a lot in advance

I would first take the 8 cm stones everywhere at a depth of 25 cm. The price difference can be neglected and they are already significantly more solid.

For the terrace, your uncle will probably be right, the joints should be enough there. For the driveway, I would definitely pour a continuous fillet. What does the ground look like? If it is quite clayey anyway, that supports well, but if it is fine sand, I would pour concrete continuously everywhere.

With a continuous fillet, you can expect about 20 kg of concrete (dry mass) per meter, with only joints about 1/3 to 1/2 of that.

You should make concrete yourself by having a big bag of gravel (grain size up to 32mm) delivered and then mix concrete accordingly with cement in a mixer.
The mix ratio is about 4:1, i.e. you will need about 12-13 bags of cement per cubic meter of gravel.
Alternatively, ready-mix concrete in 40 kg bags, but I think the other option is significantly cheaper and you will have to have gravel and other materials delivered anyway for the substructure as well as the slabs and stones.
A mixer is definitely a must, otherwise your arms will be heavy after 2 buckets of concrete.

A suitable gripping tool for the deep curb stones could also be useful, maybe your uncle can get something. It’s doable by hand, but pretty brutal in the long run. For the slabs, use a proper slab lifter.

Furthermore, it is important to keep an eye on the heights and slopes early on, you can make a lot of mistakes there.
A laser level device is great, but it is also possible with a straightedge and string plus a spirit level.
For cutting stones, a large angle grinder with a good diamond blade is recommended, ear and eye protection are mandatory.

I myself designed the terrace / garden this way, the scope was quite similar, my 75 m of curbstone. It took two of us a week, however working over 10 hours a day. Afterwards, I temporarily had carpal tunnel syndrome in both hands and forearms like Popeye.
But it turned out really well, overall a nice activity, I would do it again anytime.
If you want to do it this year, put in the effort, once it freezes, the fun is over.

Hi, thanks for the detailed answer. We wanted the 6 cm so that the curb wouldn't stand out so much. Apparently, 5 cm only comes rounded on top, otherwise we would have taken that. Regarding making concrete ourselves, I need to find out how much all the materials would cost.

Yes, as I said, you can't mix the quantities by hand, not even with a stirring rod like the tiler likes to use. You can also have ready-made concrete delivered, but that doesn't make sense because the quantity is very small and you take too long to process it. Used mixers are available cheaply in the classifieds.

Hi, I quickly checked now.

So Rheinkies 0/16 would cost me 27.73€ per ton at the Erdenwerk. 1m³ would be 1.6 tons.

He doesn't have cement.
At Bauhaus, the cheapest cement, 25kg bag chromate-reduced, would cost me 2.69€ (0.11€/kg).

The concrete screed would cost me 3.29€ (0.08€/kg) for the 40kg bag with 0/8 grain size.

So here I would already be cheaper with the ready-made concrete.

I'll keep looking where to get cement even cheaper. Although I don't find 0.08€/kg for concrete particularly expensive, do I?

I only know that our building materials dealer, who sells us the slabs and the paving, already charges 3.20€ net for the 30kg concrete bag, so 3.80€.

3.30 per sack garden-landscaping screed concrete is ok, cheap.