Membrane Removal and Crack Injection, Broadbeach, Gold Coast

The job

The Nuu Co manages the body corporate for a large strata building on Victoria Avenue in Broadbeach. The podium roof terraces, including the areas around the gym and the games room, were due for new waterproofing, and the old membrane and the concrete under it had to be dealt with first.

Perfect Concrete Care did that part of the job in stages from September 2024 to April 2025: taking the old membrane off the floors and upstands, treating the cracks in the slab, patching and coring, so the new waterproofing could go down on sound, clean concrete.

What we did

• Membrane removal from the terrace floors and upstands by grinding, with a floor grinder on the open areas and hand grinders on the walls and edges, all on dust extraction
• Breaking out the stubborn sections with a jackhammer where the membrane was bonded hard to the slab
• Crack injection of the cracks in the roof slab: sealing each crack, setting ports along it and injecting
• Patching the port holes and damaged areas, and breaking spalled concrete back to sound material, treating exposed steel and patching the walls
• Coring new outlets through the upstands, including a 117 mm core to 250 mm deep in March 2025

What made it hard

This was an occupied building. Owners used the gym, the games room and the areas around them the whole time, so each work area had to be kept separate and the dust kept under control. On many days there was no client representative on site, so the crew had to work to the plan on its own and leave every area in a state the manager could check.

The old membrane was not the same everywhere. Some areas came off cleanly under the grinder; others were bonded hard and needed breaking out first. The upstands were just as much work as the floors, and the narrow walkways meant working with hand tools in tight space.

How it was done

The membrane came off area by area. On the open decks the floor grinder took it off in strips, with a vacuum on the grinder. On the upstands and edges the crew used hand grinders, and where it would not grind off, it was broken out and ground back. Every area was left as bare, clean concrete.

With the slab bare, the cracks showed up clearly. Each one was marked, sealed along its length and fitted with ports, then injected. The ports came out and the holes were patched. Spalled areas on the walls were broken back to sound concrete, the steel was treated with a primer and the areas were patched. New outlets were cored where the new system needed them.

Lessons learned on this job

Every job teaches the crew something. These are the ones we took from Broadbeach, and we use them on every membrane removal and crack injection job.

What worked

• Take it back to bare concrete. Grinding every area right back showed up the cracks and damage that would otherwise have been hidden under the new system
• Match the tool to the area. Floor grinder on open decks, hand grinders on upstands and edges, and breaking out only where the membrane would not grind
• Extraction on every grinder. Keeping the dust on the vacuum made it possible to work next to areas the owners were using
• Leave it checkable. With no client on site on many days, leaving each area clean and finished meant the manager could see exactly what was done

What was difficult

• Working around an occupied building. Owners need access to the gym and the games room, so the work had to be staged around them
• Membrane that would not let go. Some areas were bonded hard to the slab and took far longer than the ones that came off cleanly
• Upstands and walkways. Hand work on walls and in tight spaces takes more time per square metre than open deck grinding
• Work in stages. Coming back several times over the months means planning each visit so nothing is left half done between them

If you have something similar

Body corporate managers, building managers and waterproofing contractors need the old membrane off and the concrete repaired before the new system goes down. Have a look at our coating and membrane removal, crack injection and concrete repairs Gold Coast pages, or get in touch.