Cleaning GFRC and precast without damaging either
Mineral staining on a facade built from two concrete materials that react differently to the same cleaner.
The Taylor Building is a three-storey commercial office building in Salinas, California, between San Francisco and San Jose, and the headquarters of Taylor Fresh Foods. Its facade combines precast concrete with GFRC, glass fibre reinforced concrete, along with architectural glass and anodized aluminum window frames.
What went wrong
Mineral-based staining across the concrete, and mineral deposits on the window glass. Ordinary weathering, but on a facade of this kind the stains are what people see first because the surfaces are pale and flat.
Why the material mattered more than the stain
GFRC is not the same as precast, even though it looks similar from the pavement. It is a thinner, fibre-reinforced panel, and it does not tolerate aggressive cleaning the way heavy precast does. Use something too strong and you etch the surface, which leaves a mark worse than the staining you were removing, and on a panel rather than a slab there is less material to lose.
So the work started with finding a cleaner strong enough to lift mineral staining and mild enough to leave both materials intact, rather than reaching for the most powerful product available.
What was used
Stone Restore HD cleaned the precast and the GFRC, removing the mineral staining without harming either surface.
Leach Stop followed as the sealer on the concrete. It is the step that stops the staining coming back, because it blocks the mineral leaching and water penetration that produced it in the first place.
The windows were restored with Glass ReSurfacer Final Polish, worked with a Glass ReSurfacer Pad, which cleared the mineral deposits off the glass.
The anodized aluminum frames were brought back with Metal ReSurfacer, which returns the metal to its natural sheen without stripping the anodized coating. That coating is the thing most general cleaners destroy on anodized aluminum.
How it came out
The concrete, the glass and the frames came back together, and the concrete left sealed rather than simply clean.
Products used on this project
- Stone Restore HD — cleaning the precast and GFRC
- Leach Stop — sealing the concrete
- Glass ReSurfacer Final Polish — mineral deposits on the glass
- Glass ReSurfacer Pad 6″ — the polishing pad
- Metal ReSurfacer — anodized aluminum frames