Vertical overlays can be used on a variety of projects such as wine cellars, basements and outdoor living areas. These vertical overlays can be stamped or hand carved. Contractors will find a few differences in vertical surface prep compared to that of horizontal.
According to Dan Whitaker, the Northeast representative for Butterfield Color, the manufacturer of Cantera Vertical Wall Mix, a polymer modified cementitious topping, there are not as many contaminates on vertical overlay surfaces compared to horizontal overlay surfaces.
The first step to vertical overlay application begins with using hand grinders or high-pressure washing to remove any paint. "Make sure that everything is clean and that the concrete pores are open so that it can accept a scratch coat," Whitaker says. "It is important to have a good scratch coat."
A scratch coat will give the vertical overlay something to grab on to. Apply using a notch trowel or a scratching tool. Whitaker says it is important to make the surface very rough. The scratch coat must dry, and then it can be primed.
After the scratch coat is primed, it is time to apply the vertical mix. "Vertical mixes are lightweight which allows them to be applied thicker and hang on the wall," Whitaker says.
One problem contractors might encounter when applying a vertical overlay is sagging -- material running off the wall. "That will go back to the material being too wet or the scratch coat not being rough enough," Whitaker says.
A solution to this problem is applying the mix in thinner coats, or if the material is too wet the mix will have to be removed and reapplied. Whitaker says it is essential to have a consistent mix.
Contractors can proceed to stamping the surface shortly after applying the material. The surface is ready for stamping when contractors are getting a clean impression and not tearing the surface in the stamping process. When stamping, contractors will use a liquid release. Set times are slower when working with vertical overlays making vertical stamping easier than horizontal stamping. Along with stamping, contractors can carve the overlay to create larger patterns such as rocks.
Whitaker suggests contractors create mock-ups for their customers so they know exactly what they are getting. He also suggests contractors attend classes or trainings as well as practice on small projects around their homes.
To read about surface prep for horizontal stamped overlays, read the article "Prep Basics Lead to Successful Stamped Overlays."