What happens in a crawl space during an earthquake?
What can an Earthquake do to a crawl space?
As a Foundation repair contractor, I have spent a lot of time in crawl spaces. And, I’m one of the few people who can say that they have been in a crawl space when an earthquake hit.
I was working on a home that had a door sticking. I was tightening a jack when I noticed the old block pier next to me starting to move. I looked around at the other piers and they were all swaying, some were swaying quite a bit. Two of them completely failed, they kicked out from under the joists. One fell harmlessly to open ground; the other one fell onto a water line. The water line didn’t break, but it took a fairly good hit. A few other piers throughout the home were moved, some tilted, and none of them seemed as sound as they did before the quake.
Honestly, I think the piers that fell were compromised prior to the earthquake, possibly by water or settlement; it wasn’t a major quake, nothing like what we experienced Saturday, around a 4.0. The concerns that have stuck with me since that experience was the fact that several of the piers moved, I’m concerned of a cumulative effect of several smaller quakes adding up to the damage similar to that of a large quake. The quake caused no visible damage to the interior, or exterior of the home, only the crawl space. If I hadn’t been there to witness it, I might have dismissed it as a typical failure due to water, settlement, or poor pier design.
The 5.6 quake we had Saturday was definitely strong enough to cause pier failures. Piers failures can cause water or gas leaks if they land on a pipe, or just a general lack of support under your floor joists, which can lead to very expensive repairs down the road.
What do you need to do?
Inspect your crawl space. Crawl in there and look at the piers, if you are unable to, call someone to do it for you. Inspect the piers, shake them, make sure they are tight, inspect them to see if they are leaning or off center with the joist. If one has fallen, make sure it didn’t land on and damage a pipe or an air duct. If you do have pier damage, call a foundation repair company. Crawl space repairs are very complex.
If you have any foundation or masonry questions, email me at firstname.lastname@example.org
Or call my office (580)762-9097