Ask six questions: what happens on day one, will the slab be moisture tested, what is the build-up in millimetres, which sealer and how many coats, who lays the finish, and what are the cure times in writing. A contractor who leads with preparation is telling you where their time goes. Check the QBCC licence number on the register.
Ask what happens on day one
The answer you want involves a diamond grinder, a vacuum, and a test. If day one is "we pressure wash and start coating", the bond depends on luck. Pressure washing removes dirt; it does not remove sealer, laitance, glue or paint, and it leaves the slab wet, which is its own problem.
A contractor who leads with preparation is telling you where their time goes. A contractor who leads with pattern catalogues is telling you where their attention goes.
The six questions
- Are you licensed, and what is the number? In Queensland, concreting work above the threshold requires QBCC licensing. Ours is 1109935. Check it on the QBCC register — it takes a minute.
- Will you moisture test the slab? If the answer is no, ask what happens if the slab is damp. There is no good answer.
- What is the build-up in millimetres? A contractor who knows their system knows the thickness. Vagueness here means the spec is being decided on the day.
- Which sealer, and how many coats? Two coats of a UV-stable sealer is the baseline outdoors in Queensland. One thin coat is a saving you will pay for.
- Who lays the finish? Ask whether the decorative work is subcontracted. Split crews are why finishes change halfway across a driveway.
- What are the cure times in writing? Foot traffic and vehicle times should be on the quote, not promised verbally as "a day or so".
Warning signs
A firm price over the phone without seeing the slab. Pressure to sign on the first visit. A discount for paying cash up front. No written scope. No licence number on the paperwork. Photographs that are obviously supplier marketing rather than the contractor's own jobs.
None of those are proof of bad work on their own. Two or three together usually are.
What a good quote looks like
Preparation and finish itemised separately. The system named. The build-up in millimetres. Sealer product and coats. Cure times for foot traffic and vehicles. Licence and insurance details. A clear statement of what happens if the slab fails testing once grinding starts — including whether your deposit is refundable.
That last one matters. Slabs do occasionally reveal problems under the grinder that were not visible beforehand. What separates contractors is whether that is treated as an honest conversation or an invoice.
Short answers
How do I check a QBCC licence?
Search the licence number on the QBCC online register. It shows the licence class and status. Ours is 1109935.
Should I pay a deposit?
A reasonable deposit for materials is normal. Paying the majority up front is not, and neither is cash-only pricing.
Is the cheapest quote ever the right one?
Sometimes — if it itemises the same preparation as the others. If it is cheaper because the grind, the repairs or the second sealer coat are missing, it is not cheaper, it is smaller.
Written by the Decorative Concrete Resurfacing crew from work carried out across South East Queensland. Last reviewed . QBCC licence 1109935.
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We will tell you whether it can be resurfaced, what finish suits it, and what it costs — before anyone turns up with a grinder.