After a noticeable earthquake, it’s natural to walk outside, look at the house and wonder whether the foundation is all right. This post is a checklist for that moment: what to deal with first, when to stay out, what to look at around the foundation once it’s safe to look, and who answers the questions you can’t.
It’s written for homeowners in La Jolla citywide. It isn’t a guide to preparing for a scheduled seismic evaluation (we covered that in preparing for a seismic evaluation), and it can’t tell you whether your house is safe. Only people who can see the building in person can do that.
First: people, gas, power and water
Everything about the foundation can wait until people are safe. The utility and emergency steps below come from the federal Ready.gov site (FEMA) and the Earthquake Country Alliance. We quote them rather than paraphrase, and local officials’ instructions after an actual event take priority over anything here.
- Injuries. Ready.gov: “If you are experiencing a medical emergency, call 9-1-1.”
- Damaged buildings. Ready.gov: “If you are in a damaged building, go outside and quickly move away from the building. Do not enter damaged buildings.”
- Gas. Ready.gov: “If you smell gas or hear a blowing or hissing noise, open a window and get everyone out quickly.” The Earthquake Country Alliance adds: “Shut off the main gas valve only if you suspect a leak because of broken pipes, the odor or sound of leaking natural gas, or you see the meter spinning quickly.” Ready.gov also warns, “If you turn off the gas for any reason, only a qualified professional can turn it back on,” and notes that “There are different gas shut-off procedures for different gas meter configurations, so it’s important to call your gas company.”
- Re-entry. The Alliance puts it plainly: “Until you are sure there are no gas leaks, do not re-enter your home.”
- Power. “Shut off power at the main breaker switch if there is any damage to your house wiring.” And: “If you see downed power lines, consider them energized and stay well away from them.”
- Water. Ready.gov notes that “Cracked lines may pollute the water supply to your house.”
- News. “Once you are safe, pay attention to local news reports for emergency information and instructions”
Expect aftershocks
Ready.gov says to “Expect aftershocks to follow the main shock of an earthquake.” The Earthquake Country Alliance says aftershocks “will continue to happen for several weeks after major earthquakes” and advises: “Following aftershocks, continue to check for gas leaks, chemical spills, damaged electrical wiring and broken water pipes.”
That matters for the foundation walk too. A look you took right after the main shock isn’t the last word. If there’s a strong aftershock, look again.
When to stay out and wait
Some situations aren’t for a homeowner walk-around at all. Leave the house and keep clear if you see:
- the house shifted, leaning, or off its foundation
- a chimney or masonry wall that’s cracked, leaning or partly fallen
- smells or sounds of gas, or damaged wiring
- floors, stairs or porches that have dropped or pulled away
On chimneys, the Earthquake Country Alliance is specific: “Stay away from chimneys and walls made of brick or block. They may be weakened and could topple during aftershocks.” It also says, “Don’t use a fireplace with a damaged chimney.” Ready.gov adds, “Do not try to remove heavy debris by yourself.”
Guidance written for owners of damaged buildings in ATC-20-2 (Applied Technology Council) is clear on timing: “If substantial damage is apparent, do not wait for an official evaluation of the building”. It says the prudent choice is to stop using and occupying the building.
Once it’s safe to look: a foundation checklist
If the gas, power and water are sorted out and nothing above applies, a slow walk around the outside of the house is reasonable. Wear sturdy shoes and gloves, stay out of the crawl space, and look from where you can stand safely. The point is to gather observations for someone qualified, not to diagnose anything.
Around the outside
- New cracks in the foundation wall or slab edge, especially ones that look fresh and clean
- Gaps where the house meets the foundation, or siding and stucco pulled away near the bottom of the wall
- Steps, porches, patios and walkways that separated from the house or dropped
- Cracks in retaining walls near the house, or soil that has slumped or opened up on a slope
- Water where it doesn’t belong, like a wet patch near the foundation that wasn’t there before
From inside, without climbing into anything
- Doors and windows that suddenly stick or won’t latch
- New cracks at corners of door and window openings
- Floors that feel different underfoot, or gaps that opened at baseboards
- From the crawl space hatch only, with a flashlight: anything obviously moved, broken or wet. Don’t go in.
On fresh cracks, a HUD inspection guide gives a useful general point: “A clean crack indicates recent movement; a dirty or previously filled crack may be inactive”. It also says “Cracks should always be evaluated to determine their cause and whether corrective action is required.” A crack that existed before the earthquake can still matter, and a new one doesn’t automatically mean structural damage. For more on how cracks get read, see hairline vs. structural foundation cracks and our foundation cracks page.
The California Department of Insurance makes a related point in its earthquake insurance guidance: “Some types of damage are hard to find at first.” It advises making sure adjusters “inspect the hidden areas of your property such as basements, crawl spaces, slabs, and raised foundations.”
Document before you clean up
The California Earthquake Authority says: “Be sure to take pictures of any earthquake damage to your house or its contents before you clean it up.” ATC-20-2’s owner guidance says the same: “you should document all the visible damage with photographs and a narrative of what each shows.”
Practical habits that help later:
- Photograph each crack with something for scale and write down where it is and when you took the photo
- Note which cracks or gaps you know were there before, if you have older photos
- Keep a simple log if things change after aftershocks
Our post on crack monitoring with telltales and photos covers a repeatable way to do this. The Department of Insurance also notes that “An insurance company can deny claims that are not reported within one year.” Check your own policy for its terms. This post isn’t insurance or legal advice.
What the colored placards mean
After a damaging earthquake, local governments may send safety evaluators to post buildings. In California, Cal OES’s Safety Assessment Program provides “professional engineers, architects, and certified building inspectors to assist local governments in safety evaluation of their built environment in the aftermath of a disaster.” Its training is based on the ATC-20 procedures.
ATC-20 uses three postings: green (inspected), yellow (restricted use) and red (unsafe). ATC-20-2’s guidance for owners adds a few points that are easy to miss:
- A green placard “does not imply that existing damage should be ignored or that repairs are not necessary.”
- A red placard “does not automatically mean that the property has been condemned or will require demolition.” The placard itself says “THIS PLACARD IS NOT A DEMOLITION ORDER”.
- Postings can change. The green placard reads, “Aftershocks since inspection may increase damage and risk.”
- Placards are official notices: “Do Not Remove, Alter, or Cover this Placard”.
If no one has evaluated your house and you think it needs it, the same guidance says “You can contact the jurisdiction to request this safety evaluation.” In La Jolla, that jurisdiction is the City of San Diego. The guidance also says “The evaluation may not be possible until a few days after the earthquake”. The Earthquake Country Alliance tells households to “Be prepared to report damage to city or county government.”
Who answers which question
- Is there a gas leak, or is the power safe? Your gas and electric utility, and emergency services if anyone is at risk.
- Can we be in the building? The City’s building officials, and safety evaluators working for them after a disaster. A licensed engineer you hire can also advise. Our structural engineer page explains how that role fits.
- Is this crack structural, and what repair does it need? A licensed civil or structural engineer, working from an in-person look. In certain cases, ATC-20-2 notes, “an engineering geologist may also be needed when a building site is steeply inclined”.
- What can we document and plan now? A visual structural inspection or foundation inspection records what’s visible. Our post on what a foundation evaluation includes walks through a typical visit.
- Do repairs need a permit? They can. ATC-20-2 says “Certain minor cosmetic work (e.g., replacing or patching cracked interior wall finish materials) may be exempted, but other repairs (e.g., fixing chimneys, or repairing any damaged structural members) will likely need a permit.”
A note on hiring after a disaster. The Earthquake Country Alliance warns: “Fraud is common following a disaster.” It advises, “If you need repairs to your home, check with the Contractors State Licensing Board to ensure your contractor is fully licensed.” ATC-20-2 suggests you “ask for proof of both a current state contractor’s license and a certificate of worker’s compensation insurance”.
Cost factors, not prices
We don’t publish prices for post-earthquake work, because no two situations look alike. What drives the scope and cost is whether the damage is cosmetic or structural, whether an engineer’s evaluation and drawings are needed, whether permits are required, how easy the crawl space or slab is to get at, whether chimneys or retaining walls are involved, the slope and soil on the lot, and how much demand there is for engineers and crews after a regional event. If seismic retrofit work is added to a repair, that changes the scope too.
Where we fit
We’re a foundation and structural repair company serving La Jolla citywide. Once officials and utilities have done their part and the house is safe to be around, we can visit, document the cracks, gaps and slope we see at the foundation, and explain it in plain language. We aren’t engineers or building officials, and we don’t post placards or decide whether a building can be occupied. We work with verified contractors and coordinate with licensed engineers as needed. This post is general education, not an assessment of any property.
Next step
If the house has been cleared and you want the foundation looked at after an earthquake, request a Free Quote for an on-site visit anywhere in La Jolla, or call (650) 739-6537. If anyone is in danger, call 9-1-1 first.
Sources (accessed October 28, 2026)
- Ready.gov (FEMA), Earthquakes: After an Earthquake
- Ready.gov (FEMA), Safety Skills: Shut Off Utilities
- Earthquake Country Alliance (SCEC), Step 6: Improve Safety
- Earthquake Country Alliance (SCEC), Step 7: Reconnect and Restore
- Applied Technology Council, ATC-20 Post-Earthquake Safety Evaluation of Buildings
- Applied Technology Council, ATC-20-2 Appendix A, Guidance for Owners and Occupants of Damaged Buildings (1995)
- Applied Technology Council, ATC-20-2 placards: Inspected, Restricted Use, Unsafe
- California Governor’s Office of Emergency Services (Cal OES), Safety Assessment Program, and SAP Frequently Asked Questions
- California Department of Insurance, Earthquake Insurance
- California Earthquake Authority, Manage your earthquake policy
- U.S. Department of Housing and Urban Development, Residential Rehabilitation Inspection Guide (2000)