Cost to Polish an Existing Concrete Floor: What You Need to Know

nico-robitschko
Feb 8
2 min read

One of the most common questions we hear is:“What does it cost to polish an existing concrete floor?”

The short answer is: it depends on the condition of the concrete.Unlike new slabs, existing concrete floors often require additional preparation before polishing can even begin — and that has a direct impact on cost.

In this article, we explain what affects the cost to polish an existing concrete floor and why pricing can vary significantly from one project to another.

How the Polishing Process Affects Cost

The cost to polish an existing concrete floor is closely linked to the number of grinding and polishing steps required, which depends entirely on the condition of the slab.

A typical mechanically polished concrete process involves multiple stages, each building on the previous one:

The process usually starts with 30-grit metal bond diamonds, followed by 60-grit and 120-grit metal bonds. During the metal grinding stages, a grouting liquid is applied to fill pinholes, air voids, and minor surface imperfections. Once the surface is refined, the slab is densified to harden the concrete and prepare it for polishing.

After densification, the floor transitions into resin tooling, beginning with a 50-grit transitional pad, followed by 100-grit resin with further densifier applications as required. The polishing process then continues through 200-grit, 400-grit, 800-grit, and finally 1500-grit polishing pads, depending on the desired finish level.

Each of these steps takes time, labour, and diamond wear — which directly influences cost.

Why Floor Condition Changes Where We Start

Not every floor requires the full process from the beginning. The starting point depends on the condition of the concrete.

If a floor is very uneven, damaged, or has coatings or glue, polishing must start at a much earlier stage, such as 30- or 60-grit metal bonds, to properly flatten and repair the surface.
If the slab is fairly flat and only worn from normal use, it may be possible to start at 120-grit metal bonds.
In rare cases where the floor is in very good condition, polishing can sometimes begin at a 100-grit resin stage, significantly reducing labour and cost.

Starting at the wrong stage to save money can lead to uneven finishes, visible imperfections, and long-term durability issues — which is why professional assessment is critical.

Final Thoughts

The cost to polish an existing concrete floor isn’t just about square metres — it’s about the condition of the slab and the work required to make it polishable.

While poor-condition concrete may cost more to polish, proper preparation ensures: