After a large fire, the masonry walls of a local building were covered with soot. I've been asked to determine if the masonry sustained any other damage. What should I be looking for?
Most of the problems that occur in masonry walls during fire result from thermal expansion that causes cracking. In composite walls, the tremendous heat can fracture brick headers that hold wythes together. Brick faces may spall as moisture within the units vaporizes. Excessive cracking and spalled face shells also are signs of fire damage in concrete masonry. I recommend performing a condition survey of the walls to find areas that have spalled. Cut openings in several areas to examine the condition of ties, brick headers, etc. Test concrete masonry by tapping it with a hammer and comparing the sound with that of masonry of known strength.