HEY HEIDI – The Dear Abby of Concrete Masonry
RaCHEL asks how concrete masonry can provide a resilient structure
Q: We are designing a large health care facility. What role can Concrete Masonry play in creating a resilient structure?
– Resilient Construction Has Extreme Longevity
A: Dear RaCHEL,
Concrete masonry construction has strength, durability, longevity, fire resistance, seismic and blast resistance, all of which contribute to the resiliency of the built environment. The durability of concrete masonry construction is well known and vital during the more visible aspects of natural disasters such as floods, hurricanes and tornadoes. However, there are lesser known resiliency benefits of CMU construction. Concrete masonry provides a simple and cost effective way to utilize thermal mass which helps to increase the passive survivability of a structure. Thermal mass is the ability of a material to store thermal energy, thus regulating the interior building temperature between daytime highs and nighttime lows. This, along with operable windows, helps to stabilize interior temperatures. Basically, thermal mass helps to reduce heat loss when it’s cold and helps to maintain cooler interior temperatures when it’s hot. It increases the comfort of the occupants, helping to extend the length of time that people can remain before extreme temperatures require evacuation. In the case of fire, CMU structures and interior partitions are non-combustible and durable under fire conditions. These walls compartmentalize fires and don’t allow them to spread, even if sprinkler systems fail. For exterior walls, the FORTIFIED program calls for a non-combustible building envelope with a minimum fire resistance rating of one hour. This is an easy requirement for CMU assemblies to meet, as their fire ratings go up to 4 hours while providing a durable envelope.