Grind & Seal
The concrete is ground to the desired aggregate exposure, then protected with a topical clear sealer or coating. This example uses Sparta-Guard Clear polyaspartic.
Polished concrete & grind and seal Auckland
Natural Concrete Garage Floors
Choose the aggregate exposure you like, then either protect it with a topical sealer or mechanically polish and densify the concrete itself.
Two different approaches
Grind & Seal vs Diamond Polished Concrete
Both start with diamond grinding, but the way the finished surface is protected is fundamentally different.
Diamond Polished Concrete
The concrete is progressively refined with diamond tooling and chemically densified. There is no topical coating film over the surface.
Grind & Seal
A protective barrier on top of the concrete.
A clear acrylic, urethane or polyaspartic sealer sits on the surface and provides stronger resistance to staining and chemicals. The trade-off is that this topical layer can eventually wear, scuff or scratch and may need recoating.
Diamond polish
The hardening happens inside the concrete.
A chemical densifier reacts within the concrete, making the surface harder and denser as it is mechanically polished. There is no coating film to peel or wear through because the finished surface is the concrete itself.
The trade-off is stain protection: without a continuous topical barrier, oils and staining materials can still penetrate if they are left on the surface.
Surface preparation
Diamond grinding is controlled with professional dust extraction.
Our grinders are connected directly to high-capacity dust extractors to help control airborne dust while the concrete is being ground and polished.
Indicative pricing
Choose the exposure and protection you want.
All figures are + GST. Actual slab condition, grouting, access, edges, repairs and final gloss can change the price.
| Finish | From + GST |
|---|---|
| Grind & seal · medium grind + acrylic | $80/m² + GST |
| Grind & seal · medium grind + polyaspartic | $100/m² + GST |
| Diamond polish · surface polish | $80/m² + GST |
| Diamond polish · light grind | $90/m² + GST |
| Diamond polish · medium grind | $110/m² + GST |
| Diamond polish · deep grind | $130/m² + GST |
| Deep / full exposure above a medium grind | typically +$20/m² + GST |
Polished concrete FAQ
What the final appearance really depends on.
What is the difference between grind & seal and diamond polished concrete?
Grind & seal uses a topical clear sealer or coating over ground concrete. Diamond polished concrete is mechanically refined and treated with a chemical densifier that reacts within the concrete, making it harder and denser without leaving a coating film on top.
Does deeper grinding always look better?
No. Aggregate exposure is largely a matter of personal preference. A light grind gives a more subtle finish, while deeper grinding exposes more aggregate. On an uneven slab, however, a very light grind can produce an inconsistent appearance, so we may need to grind deeper to achieve a more even result.
Why can polished concrete stain?
Diamond polished concrete does not have the same continuous topical barrier as a grind-and-seal floor. The concrete is hardened and densified internally, but oils, chemicals and other staining materials can still mark the surface if they are not cleaned up promptly.
Can a grind & seal floor be recoated later?
Yes. Acrylic sealers are generally the easiest to refresh. Polyaspartic and urethane sealers provide stronger performance but require more preparation when they are eventually recoated.
Will existing concrete defects still show?
Usually, yes. Patches, cracks, hollows, stains, aggregate variation and previous repairs can remain visible. The more natural the finish, the more the character of the original slab becomes part of the result.
Tell us about your garage
Get the right system for the floor.
You don't need to know the exact area or which resin system you need. Give us the basics and we'll narrow down the suitable options.
Auckland-wideBased in East Tamaki
Since 199925+ years solving concrete floor problems
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