Published on June 2nd, 2013 | by Henri0
New garage floor damaged by acid
Q. In the chaos of our renovations, a bottle of muriatic acid was inadvertently tipped over on our new garage slab, and a tiny amount of it leaked out onto the floor. As a result, the smooth surface of the slab has been etched away in an area about the size of a dessert plate.
Ordinarily, I’d think nothing of it, but the exposed surface too closely resembles that of the old slab, which deteriorated from (I assume) water penetrating its unfinished surface, freezing, and gradually breaking off particles, sometimes as fine as dust, from the top. The concrete of the old slab came to resemble some urban bridge abutments, which have “spalled” to the point that their rebar shows.
In the new garage, of course, I expect only the water that may drop from the vehicles parked inside, but I’m still curious whether I should seal this spot with something or even skim-coat it.
A. The etched area should be repaired to prevent further and deeper damage when salt in the snow falls off your cars. The repairs can be made with a vinyl-reinforced patching mix. Remove all loose particles with a strong jet from your garden hose or a pressure washer.
Following instructions on the container, use one of the packaged concrete repair materials available in hardware stores and construction supply houses. Some brand names are Thorocrete and Top ‘N Bond.by