Why aren’t all of the houses in fire-prone parts of California made of concrete?

by philg

The news out of Los Angeles isn’t great lately. Here’s a photo of Pacific Palisades:

It looks as though some concrete structures are still standing.

My engineering/planning question for today: Why aren’t all houses in fire-prone parts of California made from concrete? In Florida, after wooden houses didn’t come through hurricanes in good shape people decided to pay an extra 10 percent during construction and build from concrete.

Maybe my assumption that a concrete house is mostly invulnerable to fire is wrong? It’s tough for me to imagine, though, a fire so intense that it would melt concrete and take out a roof supported by concrete or steel beams, especially if the houses themselves weren’t combustible what would be feeding a fire in a neighborhood like the one shown above?

Wooden houses are obviously easier to engineer to withstand earthquakes, but concrete structures can be made just as earthquake-proof, I thought.

As it happens, I’m in Berkeley, California right now. Here’s how the smartest Californians protect themselves against a risk even bigger than fire (University of California, Berkeley Faculty Club):

20 thoughts on “Why aren’t all of the houses in fire-prone parts of California made of concrete?”

    • Thanks, for that, JJ. I thought it was interesting to see some people saying that steel-reinforced concrete doesn’t last as long as wood due to corrosion. It was also interesting to see that it would be fairly cheap to make a wooden house much more fire resistant with a metal roof and Hardie fiber cement siding (the web page for this material doesn’t highlight fire resistance, but if you click down into the PDFs there apparently is a spec for California urban/wildland border; https://www.jameshardie.com/product-catalog/exterior-siding-products/hardie-plank-lap-siding/select-cedarmill/statement-collection-colors/?color=arctic-white ). If rich Californians had to pay market insurance rates, instead of being subsidized by peasant Californians and Federal taxpayers, I guess they would re-side their houses.

    • It is fascinating to me that Californians spend time every day predicting doom via climate change and yet the richest among them apparently didn’t bother to invest relatively small $$ in what they call “climate resilience”. Floridians are tarred by Democrats as Climate Deniers and yet nearly any Floridian with some spare cash has invested in impact windows and other hurricane prep upgrades (all houses built since 2002 are already quite resistant and newer houses are yet stronger, though apparently they’re still not able to handle a tornado).

    • Now I want to go down the rabbit hole of whether homes that are at risk for wildfires could build a water well. When the fire evacuation starts, turn on the system that would make it rain around their home until the fire is out.

      JJ Donovan – Sidetracked

  4. @philg
    Once again you beat me to the full summary and comprehended this faster that I could!
    Since I now live near the power lines here in Olney, MD, where the brush is mowed frequently and far enough away, I am going to classify myself as a low risk for the fire damage.

    Although someday I do need new siding and will add this company you found to my list!

    JJD – Benefitting once again.

  6. Glazing is the weak spot. And in scenic areas, with architect designed houses, huge windows are common.

  7. I have been on a quest to build a concrete house with concrete roof for last 15 years here in Tampa Bay, FL area with no success. My last 2 houses have concrete block outer walls with poured concrete pilers every 5 feet also in these walls. All inside walls are wood and roof is wood. With the new building code roof is supposed to withstand 135 MPH winds, I just replaced my roof for 27K because of Milton in which we had just 75 to 85 MPH winds. My house is built in 2014. Every time I ask the builders why cannot they have concrete roof, they always give vague answer like too expensive or there no skill set in their company. Currently i am in design process of my next house in Asheville, NC. I have been asking around for a builder who can build a concrete house with concrete flat roof with no success. But you do see commercial buildings with concrete roof.

  8. Please look at the USA as being run by a wood Mafia. Majority of codes are based on stick construction. Now look south of the US border and all homes are cement and brick or block, just like Europe and every downtown city in the USA, all cement and steel. The pyramids in Mexico and Egypt have been standing for thousands of years. In the USA It’s really about the economy and not what is really healthy solid home construction. It’s not hard to see what is really going on. Everybody has to $$(pay) and $$(pay).

  9. In news that will surprise absolutely no one, builders build these cardboard houses as cheaply as possible. A combination of zoning and regulation drives up development costs so much, Californians would be houses made of straw, if they were made available.

    I agree with the sentiment. I think fire resistant roofs and siding would help, plus you can’t have tiki torches (palm trees) right next to your house.

  11. The answer lies in the winds of Phoenix as opposed to Santa Anna. I have no interest monetarily or otherwise. Eco Bldg. syst., they even accept foam donations for building these large Cement Foam bricks you can cut and shape to any size ( Ins. Val. R40 I heard by the builder). The lite fire retardant bricks in combo with a metal roof or solar panels and tempered windows. There has to be more innovative solutions like Eco. Then we can stop the blame game and get busy. Pragmatic philosophy my friends predicts that we need to mold around nature, not control or bend it to our will… Thank you so much Philip.

  13. Mel is right about the wood construction mafia and codes. Building codes are established and an industry grows up around meeting those codes. It is then in the interest of that wood construction industry to resist changes to the code that would hurt their business, such as emphasizing or sometimes even just including concrete houses, so an area gets locked into stick construction. And even if building a concrete house is allowed, the lack of local industry and infrastructure to build one may make it prohibitively expensive for the consumer. Thus, stick construction inertia wins.

    However, jumping straight to concrete construction is not necessarily the only answer for better fire protection. Wood frame houses can still be made relatively fire-safe if the exterior is properly protected. Metal, tile, or cementitious roofing. Fiber-cement, brick, or stone walls. Fire-rated, double-paned, small windows. If the fire can’t get in the house, the structure has a much better chance of surviving.

  14. Is there a country where average folks starting at lower middle class step on economic ladder can buy/build private home with all conveniences made out of concrete?
    This is a real question, I do not know if such country exists.
    In US this is a possibility and regular occurrence, even if someone may have to move regionally to be bale to afford wood-based dwelling with all conveniences, a bathroom per living person, and more rooms then family size.

  15. Dear Matt, Great at pointing out alternative and painful truths when dealing with city codes.
    Dear perplexed, There are so many creative people in the USA, I think building with concrete or other fireproof material and a 3D concrete printer of course, offers no impediments. It’s really the frozen machine we need to fight. There is no question the US offers great housing opportunity to anyone that is willing to put in. Long live democracy…

  16. We’re working on concrete formulations that last longer, less carbon footprint, fire proof! Why isn’t it mandated!!!

    • Nothing should be mandated. If it is good enough and affordable enough it would be picked up.

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