How To Paint Concrete Like A Pro
We grew up in a home built around the turn of the century by our boat builder-turned-contractor grandfather. Several generations were raised in that home. It boasted traditional Mediterranean architecture, a reflection of our grandfather’s European roots.
Much to our chagrin, our old family home is no longer. It was sacrificed in the name of progress. Our city called it “urban renewal.” Out with the old and in with the new. After all, “new” was synonymous with better. A significant piece of the hearts and souls of each of the members of our family were crushed the day that our old family home fell prey to the ravenous jaws of the indiscriminate bulldozer. All that remains some forty-plus years later are memories, fond memories.
Our home stood proud among other homes in our neighborhood. It consisted of a towering (from the eyes of a child) two stories with a large basement. The building had a beige dashed plaster exterior, a red S-shaped tile roof and vast archways flanked by stately sculpted columns. There were lots of windows, a multi-lite radius-top entry door, generous architectural ornamentation, two spacious verandahs at the second floor and an ample front porch that was first to greet each visitor to our home.
Some of our most vivid memories of our old home surround events which took place on that front porch. Many a family gathering took place on that porch. Although the arid climate necessitated it, air conditioning was something reserved for more modern homes. Instead, we sought refuge from the sweltering heat ambling to and fro on the canvas-clad bench swing.
The porch, located a half dozen steps above the street, was constructed of concrete and finished with a deep red paint. It was on that porch where we had our first experience with house painting. It needed a fresh coat every few years. How rewarding it was to admire our workmanship and to be objects of praise from our family.
It seems a little strange in this day and age of architecturally finished concrete to have a painted porch. However, at that time, there could not have been a more appropriate, more suitable or more welcoming finish than that red painted porch. Still, paint remains a popular finish for concrete porches, patios, paths, garages, carports and basements.
There are several factors which contribute to a successful concrete paint job. The first and most important is preparation. As with any painting project, preparation accounts for 70-plus percent of the project.
Don’t be in a rush to paint freshly poured concrete. New concrete should be allowed to age at least 28 days and it’s best to let it cure from sixty to ninety days before paint is applied. In all cases concrete should be free of surface grit, grease, oil and other contaminants which will prevent paint from sticking.
Cleaning is the first step. Clean the concrete thoroughly using a solution which consists of one cup of powdered laundry detergent and one cup of liquid chlorine bleach in one gallon of hot water. Add the bleach to the water first and then stir in the detergent. Work the solution into the concrete using a stiff bristle broom or a nylon brush. Safety first: wear safety goggles and rubber gloves. The solution should remain in place for about fifteen minutes, but should not dry. Rinse the area completely with fresh water.
Exterior areas not susceptible to damage by a water can be pressure washed or, better yet, steam cleaned to remove deep-seeded contaminants.
After a thorough cleaning the surface of the concrete should be etched using a commercial concrete cleaning product which contains phosphoric acid. Phosphoric acid is especially useful in removing rust. Another proven method for etching involves using a 10 percent solution of muriatic (hydrochloric) acid. Extreme caution should be employed when using acid. In addition to personal protection described above, wear rubber boots, long sleeves and allow for plenty of ventilation. Flush the area with fresh water after the acid wash.
Flaking, peeling paint and previously painted surfaces should be removed using a chemical paint remover, sandblaster or a mechanical abrator. Once the paint has been removed, follow the cleaning and etching steps above.
There are three types of paint for concrete; latex, oil and epoxy. Of the three, latex is the most user-friendly. It has excellent adhesion properties, allows water vapor to escape (prohibiting peeling), and is the easiest to apply since it cleans up with water.
Most latex concrete floor paints are designed to be applied directly to raw concrete. The first coat serves as a primer while a second coat offers a full, uniform and abrasion-resistant finish. Concrete floor paints are best applied using a medium to long nap roller cover. Edges can be cut in using a nylon/polyester brush or paint pad.
Oil base paints offer a harder, shinier finish. Unlike latex, oil base porch paint should be applied over a coat of oil base concrete or masonry filler/primer. Application is similar to latex, however, mineral spirits are used for clean up. Thin the primer slightly using mineral spirits. This will enhance the penetration and improve the bond. Once dry the finish coat can be applied. Oil paints can be applied over an existing oil finish provided it is clean and has been lightly etched with a Trisodiumphosphate (TSP) wash. Chipping, peeling paint should be scraped, sanded and filled with a patching compound. Oil base paints are still a favorite for porches and patios.
Wrapping up the paint choices are epoxies. Epoxy paints are the most durable and longest lasting. They are especially popular in basements as a means of controlling dampness. Epoxy paints generally consist of two separate products which, when combined, create a chemical reaction that results in an above average bond and highly abrasion resistant finish. Regarding application, traditional epoxy paints are similar to oil in as much as level of difficulty is concerned, although the new waterborne epoxies are easier to apply.
Unfortunately, man has yet to develop a paint which will not eventually be damaged by hot tires traffic. Over time, all types of concrete paint will bubble, peel or chip when subjected to constant exposure to car tires. Damage is sure to occur when tires are rotated while the vehicle isn’t moving.
Concrete stains are another consideration. Concrete stains are growing in popularity — especially for a driveway that looks like an Indy 500 pit stop. The process is similar to painting. The concrete is steam cleaned and lightly acid washed. The concrete stain is much thinner than concrete floor paint to ensure maximum penetration. The material is mixed in a five gallon bucket and mopped onto the concrete.
When dry it highly resembles pigmented concrete rather than a painted finish. The disadvantage is that concrete stains are not nearly as abrasion resistant as concrete paints and must, therefore, be applied more frequently.
We’ll never forget that special red porch at our old family home. It’s been forty-plus years since its last painting and, in our minds, it’s as bright and fresh looking as the day it was last painted.
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