Case study: New Farm
This was a residential project with a major renovation and a timeframe that seemed unachievable.
We were asked by the builder (whom we had not worked with before) to coat both of the double garages in an epoxy flake finish.
The project was quoted at a fixed price with our standard terms in place that outline nature of aspects like soundness of concrete and finish.
Interestingly, one slab was old and existing and one was new.
The old slab performed well after grinding and the coating had no problems. The new slabs can be problematic as concreters can add water, retarders and accelerants that compromise the concrete quality.
It is hard to tell the structural integrity of the concrete as the laitance (top crust) disguises what it’s like underneath until we start mechanical grinding.
What can happen is the ‘fines’ rise to the top of the slab so the top 5mm or so is a rough grind with loose concrete and the rock gets pulled out (see photos).
The new slab was one of the worst we have seen and the budget did not allow for the work to be done to our standards.
Within months, the builder called us advising the coating on the new slab had failed and come up.
As the builder had numerous project issues, we liaised directly with the owner and had a solution in place that would take 6 days.
We took the coating off, primed the slab with epoxy and used thinners to achieve penetration into the slab. We then did an additional prime coat with less thinners to get some stability before using an epoxy/sand resin trowelled on to get some stiffness back.
From here, we used a better quality epoxy and carried out our flake system with polyurethane finish.
As most people do not have two double garages, this was really interesting. We highlighted the difference between the two slabs advising the new slab had major issues.
If the new slab was the only one we worked on, our credibility with the client could understandably be one of little trust, but because the older slab held up well, the client understood the issues as we outlined. We also engaged a concrete expert who validated our concern.
After checking in with the client 3 months later, the garage experienced no problems and the client was happy.