Some things about new concrete worry owners but are normal. Others are real defects. Here is how to tell them apart in a salty Michigan winter, and what to do if the contractor will not fix a real problem.
Why is my new concrete already cracking? Is the contractor responsible for a crack that appears weeks later?
New concrete shrinks as it dries, so a few fine hairline cracks are expected. Control joints are there so most of that cracking happens in the joints. Whether the contractor is responsible depends on why it cracked and what the contract promised. A hairline crack is usually not a defect. A wide crack, a crack with one side higher, or cracking from missing joints or a weak base points to the work. Take dated photos and raise it in writing.
Why does my new concrete have dark and light patches?
Uneven drying causes most dark and light patches. Shaded spots, damp spots and areas under curing covers stay dark longer. Different truckloads, water added to one load, or extra troweling in one area can change the shade too. Most patches blend over the first few months. Patches that stay are usually permanent but do not weaken the slab.
What happens if it rains on fresh concrete?
When it rains on fresh concrete in the first hours, the rain can wash cement off the top and leave a weak, dusty or pitted surface. A weak top is the first to flake when salt and frost arrive. Once the surface is finished and hard, rain does little harm. Summer storms in south Oakland County can arrive fast, so we watch the radar and keep plastic on site.
The finish has footprints, rough spots or low spots. Is that acceptable?
No. Footprints, trowel ridges and dips that hold water are finishing defects. Small rough areas can be ground or resurfaced. Low spots matter more in Michigan, because water that sits in them turns to ice all winter and speeds up scaling. Hose the slab down, photograph where water stands, and ask the contractor in writing how they will fix it.
Are control joints really needed? The contractor says he will saw-cut them a week later.
Control joints are needed, and a week is far too long to wait to saw-cut them. Concrete starts to shrink and can crack within the first day. Saw-cut joints should go in as soon as the slab is hard enough to cut cleanly, usually the same day or the next morning. Joints cut a week later often sit right beside cracks that already formed.
My slab was poured without rebar or mesh and I found out after. What now?
Check the contract first. If it called for reinforcement and the slab was poured without rebar or mesh, the work did not match the contract, and you should raise it in writing before making the final payment. If the contract was silent on steel, your case is weaker. Steel does not stop cracks, but it keeps cracked pieces together and level when clay and frost move the slab.
My new stamped concrete is slippery, or the sealer looks cloudy or is peeling. Why?
Sealed stamped concrete is slippery when wet or icy unless a grip additive was mixed into the sealer, and resealing with the additive fixes it. A cloudy, white or peeling sealer usually means moisture got trapped under it: too thick a coat, a damp slab, or cool, humid weather. The sealer is stripped or re-dissolved and put back thin on a warm, dry day. Faded color is mostly worn sealer and sun, and a tinted reseal helps.
The surface started flaking after the first winter. Is that normal?
Flaking after the first winter is not normal. It points to the mix or the finish: too little entrained air, water worked into the top, finishing while bleed water was still on the surface, or no curing. Rock salt in that first winter makes any weakness much worse. Ask the contractor to come and look, keep dated photos, and stop using salt on it.
The concrete was poured in summer heat and now it looks bad. Was that a mistake?
Concrete poured in heat is normal in a Michigan summer, but it takes care. On hot, humid or windy days, a slab poured without precautions can get fine surface cracks, a torn finish and blotchy color. The precautions are an early start, a damp base, wind protection and curing right after finishing. If those were skipped, it is a workmanship issue. Fine surface cracks are mostly cosmetic, but a soft, dusty top will scale in winter.
The stamped pattern is crooked or uneven and I still owe the final payment. What should I do?
Raise it in writing before you pay the final balance. Send photos of each problem and ask how and when it will be fixed. Compare the work with the contract and any sample you were shown. Many owners pay most of the balance and hold back a fair amount until the defect is corrected. Do not simply stop paying without explaining why, because that can put you in the wrong.
The crew left ruts in the yard, washout and splatter. Who fixes that?
The contractor should fix ruts, washout and splatter unless the contract says otherwise. Ruts from the truck, concrete washout dumped on the lawn or in the street, and splatter on siding or the garage door are part of cleanup. Southfield clay lawns rut badly under a loaded truck in spring, so agree on the truck route before the pour. Report problems right away with photos, since splatter is easier to remove in the first few days.
My new pad is out of level. Is that a defect?
A pad out of level is a defect only if it was meant to be level. Driveways and patios are built with a slight fall so water runs off, so a little slope is on purpose. A pad for a shed, hot tub or equipment is different: if the contract said level, it should be level. Any slab that slopes toward the house or holds water is wrong, because that water freezes or ends up in the basement.
The forms were left on and now they are stuck. Is that a problem?
Forms left on too long are a nuisance, not a strength problem. They normally come off within a day or two. Boards left for weeks hold water against the slab edge, and if the ground freezes they can stay stuck until spring. Ask the contractor to remove them and to backfill and grade the edge so water drains away.
What can I do if the contractor will not come back to fix it?
If the contractor will not come back, send a dated letter or email listing each problem, with photos and a deadline. If that gets no answer, look up the contractor's licence with the Michigan Department of Licensing and Regulatory Affairs (LARA). LARA's Bureau of Construction Codes reviews complaints against residential builders and maintenance and alteration contractors, for things like negligence, unlicensed work and fraud, but it says it cannot settle contract, payment or warranty disputes. For money back, small claims court or a lawyer are the routes. Keep the contract, receipts and every message.
This page is general information, not legal advice.