If you are considering painting bricks on a building built before the 1940s please don’t do it, and I’m not just talking about design aesthetics. Historic bricks are softer than their modern counterparts and the lime mortar commonly used before the 1920s is extremely soft.
These softer masonry materials were design to breathe and if they can’t breathe you are setting yourself up for a world of hurt. When you use a sealer or paint brick of this age you often trap moisture inside which can lead to efflorescence and eventually spalling which is when the face of the brick is pushed right off the body and the brick quickly disintegrates into powder.
You may think I’m trying to scare you and you’d be right. I have restored many brick buildings where large chunks of the brick are spalling and the structure is falling apart from applying incompatible paints and coatings to the brick. Everything from masonry sealers to layers of latex or oil paints trapped moisture and the bricks slowly ate themselves up from the inside.
huh, TIL
This is what happened to that apartment last year, yeah?