Last week while I was in Portland, Oregon, I came across a brick wall with some intriguing textures. As I mentioned on Instagram, I’ve been on a brick craze lately and have been paying greater attention to colors, textures, unit sizes and bonding patterns. As you can see in the photos here, the wall is mostly red brick but there are some partial and full units with distinctly different colors and textures. I thought they were quite beautiful, and I recently learned that I’m not alone in this feeling.
When I returned to Los Angeles, I reached out to an expert who has over 4 decades of experience in the industry. He told me these are called clinker brick and the unique surfaces are the result of overheating during the firing process which vitrifies the surface. He’d recently told me that a single clay mixture can be fired in different controlled ways to achieve different colors. So the same thing happens with clinker brick, but in unexpected ways. Originally these bricks were discarded because they didn’t meet the standard uniformity that the manufacturers sought. But some architects, include Greene & Greene loved these magical accidents for the varied texture they brought to an otherwise uniform wall.
Unfortunately when the brick industry shifted to tunnel kilns the increased control meant that far fewer clinkers were created. One manufacturer, Gavin Historical Bricks in Iowa City, Iowa, now produces them on purpose to serve the renovation market as well as to meet the needs of architects and designers looking for unique finishes.
When choosing materials for a project, I’m drawn to surfaces that will age gracefully with time and increase in richness and luster. Flat, lifeless and unchanging materials do not excite me. In brick I’m particularly drawn to Ironspot clays (see the Golden Center for an example) because the glossy surface reflects light in different ways throughout the day. Clinker brick exhibit this same reflectivity but in wild, unexpected shapes and textures. Brick has long been prized for its weight, solidly and general stateliness; clinker immediately has the presence of an old material full of scars, wrinkles and stories to tell. And in the Pacific Northwest, the spontaneous growth of lichen and moss bushy like an old man’s eyebrows only adds to the charm.