Every concrete slab shrinks as it cures, and shrinking concrete cracks. That is not a defect and no contractor can prevent it. What a contractor controls is where the crack goes.

Control joints are cut to about a quarter of the slab depth, spaced in feet at roughly two to three times the thickness in inches, and they give the slab a weak line to crack along, out of sight at the bottom of the joint. Cut them late and the slab has already chosen its own line.

So when somebody promises concrete that will never crack, they are either misunderstanding the material or hoping you do. The honest version is that it will crack where the joints tell it to, and that is what you are paying for.

A patio needs to fall about a quarter of an inch per foot away from the building. It is barely visible and it is the difference between water running off and water running back against your foundation.

Get it wrong and you do not find out on a dry day. You find out in a heavy Midlands thunderstorm, when the patio sheets water toward the house and it sits against the wall and the sill.

It is worth asking any contractor what slope they are pouring to, and worth being suspicious of anyone who has not thought about it. On a patio, drainage is not a detail at the end. It is the first thing decided.

Codes limit how much the risers in a flight can vary from each other, and the reason is straightforward. People climb stairs by feel, not by looking. Once your body has learned the height of the first step, it expects every step after it to match.

One riser that is noticeably taller or shorter breaks that expectation, and that is precisely where falls happen. It is why the tolerance is tight and why the layout gets worked out before anything is formed rather than adjusted at the end.

The same logic runs through the finish. A smooth-troweled entry step looks sharp in a photograph and is genuinely dangerous wet. Anything walked on gets a broom finish.

Reinforcement only works where it sits in the slab. Concrete is strong in compression and weak in tension, and steel is there to take the tension, which means it has to be positioned in the part of the slab that is being pulled apart.

Mesh thrown on the subgrade and poured over sits at the very bottom, encased in the weakest place it could be. It is faster, it is invisible once the pour is done, and it is close to useless.

Done properly it is supported on chairs or pulled up during the pour so it ends up in the middle third. It is a small thing to ask about and it tells you a great deal about how the rest of the job will be done.

Decorative work is the least forgiving concrete there is, because the window to stamp is short and it closes on its own schedule. Too early and the pattern sinks and blurs. Too late and it will not take an impression at all.

That window moves with the weather. A hot dry Midlands afternoon shortens it considerably, and a humid still day stretches it. It is why stamped work needs enough hands on site to cover the whole pour inside the window, and why a crew that is thin on the day produces patchy results.

The other thing to know before you commit: sealed stamped concrete is slippery when wet unless a grip additive goes into the sealer, and it needs resealing every few years to keep its colour. Both are fine. Both should be said before you choose it, not after.

A hairline crack that is not moving is cosmetic. A crack with one side sitting higher than the other is settlement, and that means something under the slab moved.

In the Midlands that is usually the base: fill that was never compacted, or clay that holds water and shifts. Replacing the slab without dealing with what is underneath produces exactly the same result in a few years, and the second time it costs the same as the first.

So the assessment starts underneath. Sometimes the honest answer is that the concrete is fine and the drainage is the problem, which is a cheaper conversation than the one you were expecting.

People assume a retaining wall fails because the soil is too heavy for it. Usually it fails because water built up behind it and had nowhere to go.

Saturated soil is far heavier than drained soil, and it exerts hydrostatic pressure on top of that. A wall designed for drained backfill and then built without drainage is carrying a load it was never sized for, every time it rains hard.

So the gravel, the filter fabric and the drain line behind the wall are not optional extras. They are the thing that keeps the load within what the wall was built to take, and they are invisible the moment the backfill goes in.

Two quotes for the same driveway can differ by thousands and the finished slabs look identical on the day. The difference is under them: how deep the excavation went, how much base stone was placed, and whether it was compacted in layers or dumped and driven over.

None of it is visible after the pour, which is exactly why it is the first thing cut. And it is the reason for almost every slab that settles, cracks unevenly, or sinks at one end a few years later.

So ask any contractor how deep they excavate and what base they compact to. On a driveway it is a more useful question than anything about the concrete itself.

South Carolina licenses contractors through two boards, and the trigger amounts are different for each. Commercial work is regulated once the total construction cost exceeds ten thousand dollars, under the Contractor's Licensing Board. Residential building is regulated above five thousand, and residential specialty work above five hundred, under the Residential Builders Commission.

Concrete is an explicit subclassification on the commercial general contractor licence, alongside things like grading, roofing and swimming pools. Commercial licences also carry group limits by size, from a hundred thousand dollars per job at the lowest group up to unlimited at the top.

It matters to a customer for one specific reason: under section 40-11-370 it is unlawful for an unlicensed contractor to perform work requiring a licence, and contracts with unlicensed contractors may be unenforceable. If the work goes wrong, that can affect what remedies you have. The state publishes the record at verify.llr.sc.gov.