The job
Infinity Constructions Group engaged Perfect Concrete Care on the concrete works for a multi level commercial head office fitout at 8-24 Kippax Street, Surry Hills. The package ran from April 2025 and covered core drilling, cutting, patching and grinding across the floors as the fitout moved through the building. This page is about one part of it: the crack repair.
Across the suspended slabs the builder had cracking to deal with before the floor finishes went down, much of it fanning out from the column bases into the floor plate. Separately, structural cracks in the blade columns and spandrel beams on the facade line needed epoxy crack injection as well. We were asked to do both.
What the work involved
- Walking each floor with the builder and marking every crack to be treated before anything was cut or drilled
- Slab cracks routed out along their length, cleaned and sealed flush, so the floor finish sits flat over the repair
- Cracks in the blade columns and spandrel beams surface sealed, ported and injected with epoxy resin
- Ports and surface seal removed and the faces made good once the resin had cured
- Working floor by floor around the fitout trades, their materials and their set out, on the same programme as the rest of the concrete care package
What made it hard
The building was a live fitout. Partition set out was on the floor, stock was stacked on the slabs and other trades were working the same levels at the same time. Every repair had to be sequenced with the builder so the floors we needed were clear when we needed them, and cured before the next trade came through.
The slab cracking was widespread and irregular. The photos show the pattern: cracks radiating from the column bases across the floor plate, some of them running for metres. Each one had to be followed to its end, chased out and filled, not just patched where it was most visible.
The structural injection was on the facade line, in the blade columns and spandrel beams between the brick panels. That is a different job from sealing a slab. The crack has to be sealed at the surface, ported at set spacings and injected so the resin travels through the full depth of the crack and bonds the concrete back together, then the face is cleaned up so the facade reads as it did before.
How it was done
Slab cracks were routed with a crack chasing saw, blown out and cleaned, then sealed with a repair compound worked flush to the slab. Where the fitout set out ran across a crack we worked around the marks so the following trades did not lose their lines.
On the columns and beams the crack was surface sealed with epoxy paste, injection ports were fixed along it and the resin was injected port by port so the crack was filled through its depth. Once cured, the ports were knocked off and the surface ground back. That is the standard crack injection method and it is the same one we use on car parks, basements and facades across Sydney.
The crack repair ran across 22 shifts between 30 March and 20 July 2026 and sat inside the wider package, so the same crew that was cutting, coring, patching and grinding for the fitout picked up the crack work as each floor came free. One contractor, one point of contact for the builder, one set of inductions.
Outcome
Slab cracks across the fitout floors sealed and flush ahead of the floor finishes. Blade column and spandrel beam cracks on the facade injected and made good. The crack work was closed out in July 2026 and the rest of the concrete care package carried on with the fitout.
If you have something similar
Cracked slabs, columns and beams on a live commercial fitout are not unusual, and the fix is not hard if it is planned in with the builder early. Have a look at our crack injection, concrete scanning, concrete cutting and concrete grinding pages, or get in touch and tell us what you are looking at.
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