I visited the missions of San Antonio. The walls there were made of limestone and concrete. If you look at the limestone, you’ll see that nature has literally melted inches off the surface. There are two forces of nature working against the stone:
- One of them is freeze-thaw. When water saturates into the surface of the stone and freezes, the water expands. At the same time, the stone contracts when freezing. This process slowly eats away the rock surface.
- Secondly, we have what’s called acid rain. Acid rain means the water alone over time melts the surface.
Call Deck & Patio Care by Barry Hagendorf today to schedule your next project at 210-822-9147.
Tips & Advice on Pebblestone Sealing
Pebblestone finished concrete is created when the contractor orders concrete with specially sized rock to be added to the standard cement mixture. Next, the contractor trowels the cement smooth and waits about an hour for it to set. After the concrete has set, water is used to wash the concrete from the surface, exposing the ordered rocks. The concrete with the exposed pebbles is then left to dry. The problem with this application is the exposed rocks (pebblestones) have a thin layer of concrete on them.
The solution: Allow the concrete to cure 14 days, then acid wash the rocks while taking precaution to protect the grass. This will chemically remove the concrete film from the rocks allowing you to see the natural golden color of the rocks – instead of the white concrete film.
Sealing: After the pebblestone has been acid-washed and power washed, allow it to dry for 24 hours. There are two methods of sealing available:
- Seal with clear acrylic and get a wet look allowing the rock color to stand out
- Seal with penetrating sloxene sealer to have a natural flat finish.