Concrete Floors near you

Queensland's Standards and Tolerances Guide is unusually direct on this point. It says that within the first twelve months, the finish to a concrete slab is defective if it is not suitable for the documented applied finishes, and it names polished concrete among them along with tiles, carpet and sheet flooring, including set-downs where required. In other words, if a new house was documented with a polished concrete floor, the slab has to have been poured and finished to suit that — which is why polishing an existing slab that was never intended to be seen is a different proposition.

The guide also sets the levelness numbers. New floors are defective within twelve months if they differ in level by more than 10 mm in any room or area, or more than 12 mm in any 3 m length, where that affects safe use or reasonable amenity, with overall deviation across the entire building footprint not exceeding 20 mm. Those are the same numbers that govern what a grinder can flatten, because grinding a slab level is limited by the cover over the reinforcement.

For cracks, the guide reproduces a damage classification from AS 2870 for concrete floors, running from hairline cracks under 0.3 mm with a change in offset from a 3 m straight edge under 8 mm, up through distinct cracks under 2.0 mm at Category 2, wide cracks of 2 mm to 4 mm with 15 mm to 25 mm of offset at Category 3, and gaps of 4 mm to 10 mm with more than 25 mm of offset at Category 4. Category 3 and 4 cracks to slabs are defects; Categories 1 and 2 are not. That table is the honest starting point for a conversation about whether the cracks in your slab are a feature you can live with or a problem to solve first.

It begins with exposure, which is destructive and informative. The old covering, the adhesive, the tack strip and any levelling compound come off, and only then can anyone see the slab. This is the moment when the honest contractor renegotiates: a slab with a heavy adhesive residue, a set of service trenches, a patched section where a wall was removed, or a tiled area that was recessed, all change what is achievable.

Then a test patch, and it is worth insisting on one. A small area ground to the proposed exposure, in a spot you will see every day, tells you more than any photograph of somebody else's floor. It shows the actual aggregate in your slab, the actual colour, and how any repairs and joints will read. It also lets you discover before the whole floor is committed that you want less exposure, or more.

Grinding, patching and densifying follow, in passes of progressively finer diamonds, with the slab vacuumed between passes. Repairs are made with a matched patching compound and they will always be visible to some degree, because a repair has no aggregate. Then a densifier reacts with the concrete to harden the surface, and finally either further polishing to gloss or a sealer, depending on the system.

Concrete is a crystalline silica substance, and grinding it produces respirable dust. SafeWork NSW names concrete among the materials containing crystalline silica and states a workplace exposure standard for respirable crystalline silica of 0.05 mg per cubic metre averaged over eight hours. Since 1 September 2024 the processing of crystalline silica substances has been more tightly regulated across all industries, with additional duties where processing is assessed as high risk, including a silica risk control plan, worker training, air monitoring and health monitoring.

Those duties belong to the contractor, not to you. What you should ask about is control: whether the grinders run on-tool extraction into a high-efficiency vacuum, whether wet grinding is being used and what happens to the slurry, how the work area is sealed from the rest of the house, and whether the ducted air conditioning returns are being covered. Grinding an internal floor in an occupied house is one of the dustiest things that can happen inside a home, and the difference between a well-controlled job and a poor one is enormous.

Plan to be out of the room, and for a house-wide job, out of the house. Fine dust settles for days after the machines stop, and getting it out of soft furnishings, wardrobes and ducted air conditioning afterwards costs more than the floor did.

Almost every dispute about a polished concrete floor is a dispute about appearance, and the cure is a sample made on your own slab. Write the test patch into the quote — its location, its size and the fact that it is the reference for the finished floor — and photograph it. Then write down the exposure level, the gloss level, the joint treatment, how existing cracks and patches will be handled and what they are expected to look like, and the sealer or densifier system.

Be explicit about the limits too. A concrete floor follows the slab's falls, so a slight fall to a former wet area will remain. Repairs will be visible. The aggregate is whatever went into the truck. Getting that written down as an agreed characteristic rather than a defect is what protects both sides.

Behind the contract, the Australian Consumer Law guarantees apply: acceptable care and skill, fitness for any stated purpose, and supply within a reasonable time. Queensland's guide is also a useful yardstick if a dispute arises, because it publishes the crack categories and level tolerances that a slab is judged against. Use LokalMatch to get a few contractors to look at the same exposed slab — not at photographs of it — and to quote against the same test patch.