Why we grind concrete instead of pressure washing it

Preparation is the whole job

A resurfacing product is only ever as good as its bond to the concrete underneath. Get that bond right and the finish holds for years. Get it wrong and it lifts, bubbles or flakes, usually somewhere between the second and fourth summer.

Preparation is also invisible once the job is done, which is exactly why it is where corners get cut. Nobody can see it from the kerb.

What pressure washing actually does

Pressure washing removes loose dirt and surface grime. That is genuinely useful, and it is fast, which is why some companies stop there.

What it does not do is open up the concrete. A slab that has been sealed, painted, oiled or simply closed up over years of weathering stays closed. The new product then sits on top of a smooth, contaminated surface rather than keying into it.

What grinding does differently

Mechanically grinding takes the top layer off. It removes old sealer, coatings, laitance and contamination, and it leaves a slightly open profile for the new material to grip.

It is slower, noisier and more expensive to do. After the years we have spent resurfacing across Sydney, we consider it the bullet-proof method for longevity, and we grind every surface we work on.

Acid washing is the other shortcut

Acid etching is sometimes offered as a middle ground. It does open the surface chemically, but the result is far less consistent than grinding, it struggles with coatings and oil, and the residue has to be neutralised and disposed of properly.

We do not use it as our preparation method.

What to ask before you sign

Three questions will tell you what you need to know.

• How will you prepare the surface, specifically?
• What happens to the existing cracks and spalling before the new surface goes down?
• What warranty applies, and what does it exclude?