Stroll down any street in Baltimore or Washington, D.C. and you are bound to find numerous brick buildings sporting a fresh coat of paint. The trend of painting brick facades has become popular over the last several years and while painting brick can provide an updated appearance, it may not be the best idea.
Brick masonry is naturally porous, meaning it contains small holes which allow liquid and air to pass through. Two common types of masonry wall assemblies we see locally are drainage wall systems and mass wall systems, both of which manage the water that inevitably enters through the porous masonry. Drainage walls contain an air cavity between the brick veneer and the back-up structure, allowing water to travel within this cavity and exit through flashings and weep holes. In comparison, mass walls contain multiple layers of brick masonry which rely on the wall thickness and bond between the bricks to resist water penetration into interior spaces. The majority of older and historic masonry buildings consist of a mass wall system.
Most paints readily available are not vapor permeable, more commonly known as breathable. Therefore, when paint is applied to bricks, they lose their porous nature which is critical for allowing evaporation in mass wall systems. The loss of porosity can cause any moisture that enters the wall system (through small cracks or other defects) or was present prior to paint application, to become trapped. This can cause bricks to deteriorate faster and can potentially trap moisture against interior framing elements, resulting in structural damage. Trapped moisture can also cause the paint to blister and flake, creating an unappealing appearance.
Additionally, masonry requires periodic maintenance. Painting brick can make it difficult to identify defects, such as cracked bricks and mortar, that should be repaired. Paint is also relatively permanent. Once brick is painted, removal can be very challenging and could result in significant damage to the brick walls.
However, there are options for updating the appearance of a brick façade, including brick stains and some breathable coatings. If you are interested in modifying the appearance of a brick structure and are looking for professional help, ETC can provide a solution.