Is your home built pre-1950S – you should definitely read this blog
Homes sit on top of foundations!
The concept of building a home on top of a foundation has not changed in 100 or more years. In fact, most homes in Los Angeles have been built on foundations whose job it is to keep the home safe from harm when a natural disaster hits, for example a flood, landslide, or earthquake.
Modern foundations are made out of concrete which is mixed in precise measures in industry “batching plants”. These plants combine various ingredients such as gravel, cement, and water, to create a strong concrete mixture. To add extra strength to this mixture, building contractors add steel bars (“rebar”) that are placed within the concrete, reinforcing it and providing it with great structural and tensile strength.
So, is there a problem?
Yes, the problem is, that homes built in the 1950s or earlier (and there are thousands of such homes in Los Angeles) were built on foundations made from hand-mixed concrete that contains little or no steel rebar to give it extra strength. Such old construction homes are also not anchored to their foundations, despite THE Federal Emergency Management Agency’s (“FEMA”) warning that homes that aren’t bolted to their foundations are vulnerable to damage from earthquake shaking.[i]
Moreover, decades of rainy seasons and bone-dry Summers — as well as frequent earthquakes – could have cause such an old home’s unreinforced foundation to weaken and crack. And a brittle, damaged foundation can no longer safely support an old home when a natural disaster strikes, especially an old home that is not bolted to its foundation.
Some older foundations are even more worrisome!
Owners of old homes should be even more concerned if their home’s foundation is not even made out of cement! Interestingly, many older foundations were actually formed out of bricks or river rocks held together with simple mortar. Such foundations are completely unreinforced and are, over time, especially vulnerable to moisture, soil settlement, and seismic activity. If your home sits on top of a brick or rock foundation, it is imperative that you examine it to determine how well it is holding up!
What’s to be done?
Owners of homes built prior to the 1950s should have their foundations inspected by a qualified professional who can assess the foundation’s condition, bolt the home to its foundation, and repair or replace a damaged foundation in a cost-effective way. All this work can often be done without even lifting the house! In fact, the Los Angeles Times recently advised that “bracing and bolting your house to current seismic safety standards can make all the difference” when an earthquake hits![ii]
All owners of old homes should inspect their foundations! The professionals at Weinstein Construction are foundation experts so call Angela today at (800) 862-6582 for a free inspection and review of all your foundation needs.[i] National Earthquake Hazards Reduction Program, “South Napa Earthquake Recovery Advisory: Earthquake Strengthening of Cripple Walls in Wood-Frame Dwellings”, FMEA P-1024 / RA2 / September 2019. [ii] The Los Angeles Times Column, “We can’t prevent the Big One, but we can give our homes a fighting chance against earthquakes”, Steve Lopez, , July 1, 2017.