The pour decides the finish
If you're planning polished concrete for new construction, talk to a polishing contractor before the concrete is ordered. Almost everything that limits how your floor can look gets decided at the pour, and if we show up after that, we're working with the slab you have.
That's the big difference between a new build and the remodel work we cover on our residential polished concrete page. On a remodel you find out what the slab is like. On a new build you get to choose it.
What to settle before anyone orders the concrete
The mix and the stone in it. If you want the stone in the concrete to show, its type, size, and spread matter. The supplier also needs to know this slab is the finished floor, because standard concrete mixes aren't made with looks in mind.
Flatness. A flatter pour needs less grinding to get level, and it usually gives a more even cream finish (the smooth top layer with very little stone showing). Agree on how flat the floor should be with the builder and the finishing crew instead of hoping for the best.
Finishing technique. Too much troweling can leave the surface hard and tight, and then we can't predict how it'll take our diamond grinders. Shiny marks the trowel leaves can also show through a shallow cut. Tell the finishing crew a polished finish is planned before anyone picks up a trowel.
Curing. Even curing means even surface strength. Patchy curing means patchy results, and sometimes you can't see them until the first grinding pass.
Pour order. Where one pour stops and the next one starts, you can get visible lines in the color. If the floor needs to look like one continuous surface, plan the pour order around that.
Who decides what, and when
| Stage | Decision | Who owns it |
|---|---|---|
| Design | How much stone shows, how shiny | Owner + polishing contractor |
| Before the pour | Mix, stone, flatness | Builder + supplier |
| Pour | Finishing technique, curing | Builder + finishing crew |
| After curing | Slab protection goes down | Builder, named trade |
| Middle of the build | You approve a sample or mockup, if the job calls for one | Owner + polishing contractor |
| Late build | Polishing window | Builder’s schedule |
| Handover | Floor stays covered through final interior work | Builder |
Protection is where most new floors lose quality
A slab sitting through framing, drywall, plumbing, and painting takes a beating. We often look at new floors with chips from dropped tools, paint and glue splatter, and rust marks from steel left out overnight. On some, taped covering pulled at the surface as it came off.
We can grind some of that out. But deep chips and some stains go further into the slab than the depth we agreed to grind. That leaves two choices: grind deeper than planned, which changes the look, or live with the mark.
The question to ask your builder
“Who is in charge of protecting the slab between the pour and polishing, and what are they covering it with?” If it isn't someone's named job, it often gets skipped.
Ask for a covering that won't leave glue behind and keep it down until polishing. If other trades still have work to do after polishing, cover the floor again.
When to fit polishing into the schedule
A new slab usually needs about 28 days before we polish it, though the wait depends on the slab and the finish. We check on site that it's ready instead of trusting the calendar.
Timing is a real tradeoff. Polish early and the floor has to survive everything that comes after, but polish late and you squeeze the schedule when it's busiest. On many builds we polish before the final interior work, then keep the floor covered through the last stages. Either way, put it in the schedule early so the other trades can plan around it.
Approve a sample on your own slab
When the job calls for it, we grind a small sample area once the slab has cured. It shows the actual stone, the color, and a close preview of the finish in your building's own light. This is the time to confirm or change the finish, because you're looking at your own concrete, not a photo of someone else's.
How much stone shows and how shiny the floor gets are separate choices. Our aggregate exposure guide explains how the depth we cut changes how much stone you end up seeing.
The mistakes we see most on new builds
Nobody told the concrete crew. The slab gets poured and finished like any structural slab, because that's what everyone assumed it was. Mix, flatness, and finishing technique all get decided without the finished floor in mind.
Protection arrives late. Covering goes down after framing has started, so the slab has taken its worst damage before anyone thought to protect it.
Taped protection. Covering held down with the wrong tape leaves glue around every joint, and that glue has to be ground off, sometimes deeper than the depth we agreed on.
Trades using the slab as a workbench. Cutting tiles, mixing compound, and standing steel on the floor all leave marks. Rust is the worst of it, since those stains can sink deeper than a shallow cut will reach.
Polishing scheduled with no buffer. Every delay from the trades before us lands on the flooring window, and our crew shows up to a floor that isn't clear.
The sample approved in the wrong light. A sample checked under temporary site lights looks different once the building's own windows and light fixtures are in.
None of these are unusual. Every one of them is cheap to prevent and expensive to fix.
A short checklist before the pour
- Make a first call on how much stone shows: cream, salt and pepper, or exposed aggregate.
- Tell the builder the slab is the finished floor.
- Agree on the mix and the stone with the supplier, with that look in mind.
- Agree on how flat the floor should be, and confirm who's finishing the pour.
- Write slab protection into the schedule with a named owner.
- If your job has a sample or mockup, book a time to look at it once the slab has cured.
- Slot the polishing window into the schedule, with protection after it.
Get those right and the polishing usually becomes the easier part of the project.