Pros and Cons of Concrete Coatings
By: Joe Czaszynski
Concrete is among the most durable products in building construction. Since concrete is porous however, it’s not able to shed water. Instead it absorbs water and any contaminants within that water. Typical freeze/thaw cycles lead to the deterioration of concrete. This is where concrete coatings come in. Coating shed water and help concrete withstand the weather elements common to the Northeast’s climate.
Several factors should be considered when choosing a coating system such as: where the coating will be applied, and the level of vehicle or foot traffic it needs to endure. Whether the coating will be exposed to any chemicals or ultraviolet light should be taken into account. For example, a concrete parking deck with a loading dock for truck deliveries would need a thicker reinforced system than a parking deck used solely for cars.
Depending on where it’s being applied, coatings can be a simple single component roll on system such as paint, or can be a complex two component system made up of several coats with reinforcement or aggregate mixed in. Single component coatings are typically applied at vertical surfaces, such as parapet walls or decorative concrete on facades. Multiple component coating systems are typically used at parking decks or pedestrian traffic areas where thicker systems with reinforcement and traction are necessary.
While the application of a coating will increase the lifespan of the concrete, the coating itself will need to be routinely inspected and maintained. Sealant joints, surface wear, and granular retention should be periodically monitored. This coating inspection and maintenance, however, is much more cost effective than having to repair concrete surfaces or structures that have not been coated.
Esthetics are also important when choosing a coating system. Coatings can revive the look of a façade, or rejuvenate the surface of a parking deck. Some coatings come in a variety of colors. Corporations can have their logo colors applied to their building surfaces to optimize branding. Colored coatings can be applied to differentiate drive lanes from parking areas and pedestrian walkways. Coating application can mask imperfections in concrete, which again is more cost effective than repairing or replacing the concrete itself. And since the cost of concrete replacement is high, damaged concrete features are often removed rather than being repaired or replaced. This alters the original look or design of a building or structure, and can have a negative aesthetic impact.
Depending on the type of coating installed, typical warranties range from 5 to 10 years. However, proper maintenance can extend a coating’s lifespan beyond its warranty. If a maintenance and repair plan is adhered to, a coating nearing the end of its lifespan can be re-coated. Conversely, if no maintenance or repair is performed, it’s likely that a complete removal and replacement of the coating system, with possible concrete repair, would be required.