The job
Rooftop membrane grinding on the top roof of a high rise residential tower in Broadbeach, on the Gold Coast. The roof is an open concrete deck with plant rooms, exhaust fans, ductwork, vent pipes and a low parapet, with the ocean on one side and Surfers Paradise up the coast.
NCR, a remedial builder, was putting a new waterproofing system on the roof. The old liquid applied membrane had to come off first, all of it, back to bare concrete. NCR brought in Perfect Concrete Care to do it. Our Queensland crew started on 11 August 2026 and finished on 1 September.
What the rooftop membrane grinding involved
- A test grind on day one to pick the right tooling, then diamond grinding with PCD discs to strip the membrane rather than just scratch it
- Walk behind floor grinders and a three phase grinder on the open deck, in passes, back to bare concrete
- Hand grinding the membrane off the parapet upturns, plant plinths, fan bases, vent pipes and hobs
- Every machine running into an H class dust extractor, with the work area taped off and leads up on stands
- Surface preparation across the whole roof so the waterproofer had a clean, sound slab
What made it hard
It is the top of a tower, so it is exposed. Wind and showers come through fast, and a wet slab won't grind clean. The crew worked around the weather and kept the leads and gear tied down and clear of the parapet.
The roof is full of plant. Exhaust fans, ductwork, vent pipes and plinths are spread across the deck, so the floor grinders could only do the open runs. Everything around and under the plant, and every upturn, had to be done by hand.
People live below. PCD grinding makes dust, so every machine was on an extractor and the deck was cleaned as the crew went.
How it was done
The crew started in one corner, ran a test grind to confirm the PCD tooling, then worked the open deck with the walk behind grinders, a first pass to break through the membrane and a second pass to take it back to clean concrete.
The hand grinders followed on the upturns, plinths, fan bases and vents. The first half of the roof was ready to hand over to NCR in the second week, so their waterproofer could get going while we finished the rest.
Outcome
The roof deck, parapet upturns, plant plinths and vents were all back to bare, clean concrete by 1 September 2026, and NCR's project manager was happy with the finish. The roof was ready for the new waterproofing system.
Lessons learned on this job
Every job teaches the crew something. These are the ones we took from this Broadbeach roof.
What worked
- A test grind on the first day, so the tooling was right before the real work started
- PCD discs on the floor grinders, which strip the membrane in two passes instead of loading up
- Handing over the first half early, so the waterproofer was not waiting on us
What was difficult
- An exposed rooftop where wind and showers change the plan quickly
- A deck full of fans, ducts and vents, with a lot of hand grinding around them
- Keeping the dust down on top of a building people live in
If you have something similar
Remedial builders and waterproofers re-doing a high rise roof on the Gold Coast need the old membrane off cleanly, with the building still occupied. Have a look at our waterproofing membrane removal Gold Coast, concrete grinding Gold Coast and coating and membrane removal pages, see our roof terrace job at The Oasis, Broadbeach, or other rooftop jobs for NCR at Infinity Apartments, Hamilton and Windsor. Or get in touch.
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Perfect Concrete Care acknowledges the Aboriginal and Torres Strait Islander people as Traditional Custodians of the country on which we live and work. We pay our respects to the Traditional Custodians and Elders past, present and future, and honour their connection to the land and ongoing contribution to society.