If California wasn’t already concerned with unreinforced masonry buildings, the earthquake on August 24th reminded them of the building safety concerns tied to these structures. The estimated $1 billion worth of damage showed that the numerous unreinforced masonry buildings were not safe and making the needed retrofits was at the very minimum, costly.
Even knowing that the recent earthquake was the worst the area had seen in 25 years, it didn’t make these concerns any less valid. Building safety should be at the forefront of any and all conversations our industries engage in. This occurrence just further shed light on these brick, stone, and concrete buildings that are more likely to crumble or collapse. California has long recognized the issue and the potential that the mortar between bricks can deteriorate, creating dangerous situations even when an unreinforced masonry building goes through the costly retrofit. Even knowing some of these structures present safety concerns the costs can often deter the owners from taking the immediate and necessary safety precautions. The California Seismic Safety Commission recently reported that nearly 70% of the 25,000 plus brick buildings in California had either been retrofitted or demolished now.
Mortar between bricks and concrete can deteriorate over years, and is commonly stated as not being strong enough to withstand earthquake damages. Even after costly retrofits to these buildings, these weak joints can contribute greatly in walls crumbling to the ground.
Reading through the several articles over the last couple of weeks, I had to ask myself whether or not an EIFS cladding could help. The image that continued to be blasted across articles and the TV screen was one of individual bricks lying on the sidewalks and streets. To start, EIFS offers the benefit of being a lightweight alternative that is completely bonded to the substrate, meaning the chances of a small pieces breaking loose and potentially falling is minimal at best. The lightweight characteristic of EIFS becomes very beneficial in areas prone to earthquakes. Whereas other buildings may become top heavy with the heavier cladding options, EIFS will actually do the opposite.
In the case of these unreinforced masonry buildings, I have to consider that the best solution is to outright replace the areas of masonry causing the concerns. Assuming a substrate exists behind the exterior brick a solution where EIFS replaces the brick cladding is completely feasible. If concerns have already been outlined with the performance of these buildings, it seems like an alternative that should at least be considered. If the masonry walls are holding up to a satisfactory level adding EIFS as an exterior cladding to these walls may assist in preventing individual bricks from coming loose in a future event.
This being said there are situations when every precaution can be taken, and it’s still not enough. The difference in the most recent earthquake in California is how the buildings broke apart that raises the concern. The mortar between the bricks was deteriorating, allowing for bricks to fall to the ground while the building’s walls crumbled. If the situation had involved EIFS the exterior wall cladding would’ve stayed put unless the entire substrate behind it crumbled.
In general, it’s believed that EIFS would respond well against the effects of an earthquake, similar to the sterling results achieved by EIFS in potent hurricane areas.