Say I have a portion of 10x10 feets. I need to put a concrete slab for that. The thickness of the slab will go 4 inches.

Is there a way to tell, how much weight this slab can carry?

  • What is the soil like that the slab is going on?
    – WarLoki
    Commented Sep 13, 2015 at 13:30
  • Does it have rebar? Wire mesh? Fiberglas mesh? Commented Oct 13, 2015 at 20:20

2 Answers 2


Depending on the percentage of the portions in the mix , a fully cured slab of concrete should have a compressive strength of between 2200-5000 psi. So depending on what the slab needs to support will determine the thickness and configuration of the concrete. A standard residential driveway is commonly 4-6 inches thick concrete with re-enforced steel bars. A residential garage normally is constructed on a 4 inch mono-lithic re-barred slab. These are just generalizations and you should consider all extenuating factors for your project for your region.


The answer is E. Not enough information.

Even more important than the mix is what is under the concrete. If you poured concrete on granite bedrock you could probably put the heaviest piece of equipment in the world on it without any issues.

The factors here:

  • what is under the concrete. If it is a loose rock bed or there are cavities then it will hold A LOT less. If the area under is packed solid, it is going to be almost impossible for the concrete to fail.

  • the mix. This is probably more important for the top layer to not fail. If you have packed ground the biggest concern is if the top layer will scrape off or having issues due to weight.

  • the internal support for the concrete. The rebar infrastructure or any other sort of mesh support.

What you are asking us is will your install hold a certain amount of weight. Unless you have pictures take during the install it will probably be impossible to answer. If it makes you feel better we were redoing a country house and one of my guys parked a 40 ton excavator on the patio for a weekend... a couple of scuff marks but no issues.

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