Physical Recovery
How to evaluate structural safety after a disaster. What the placards mean, what to look for, and when you need a structural engineer.
Before You Enter
Do not enter a damaged building until local authorities have cleared the area. Check for downed power lines on or near the structure, smell for gas before opening the door, and look for visible structural collapse from the outside. If the building is visibly leaning, partially collapsed, or has a red placard posted, do not go inside.
Action Checklist
After a declared disaster
After a federally or state-declared disaster, building inspectors and trained structural engineers evaluate damaged buildings and post colored placards on the exterior. This system, developed by the Applied Technology Council (ATC-20 for earthquakes, ATC-45 for wind and flood), is used nationwide to communicate building safety status quickly.[1]
Green: Inspected
The building has been inspected and appears safe for occupancy. This does not mean there is no damage. It means the inspector found no conditions that make the building immediately dangerous. You may still need repairs, and you should still document everything for insurance.[2]
Yellow: Restricted Use
The building has damage that limits how it can be used. The placard specifies the restrictions: you might be allowed brief entry to retrieve belongings but not overnight occupancy, or you might be restricted from certain areas of the building. Read the specific conditions printed on the placard and follow them.[2]
Red: Unsafe
The building is unsafe to enter. There is an immediate risk of collapse, structural failure, or other life-threatening conditions. Do not enter a red-tagged building. Entry may require a permit and supervision. If you need to retrieve essential items, contact your local building department about supervised access.[2]
Not all disasters result in placard posting. Smaller events or areas outside of declared disaster zones may not receive building inspections. If your building has not been inspected and you are unsure whether it is safe, hire a licensed structural engineer before entering.
Reading the building
Hairline cracks (less than 1/16 inch): Common in concrete, especially in newer construction. Usually cosmetic. Monitor but not urgent.[3]
Stair-step cracks in block or brick: Follow the mortar joints in a stair-step pattern. Indicate differential settling. Have a structural engineer evaluate.[3]
Horizontal cracks: Among the most serious foundation problems. Indicate lateral pressure pushing the wall inward. The wall may be bowing and could eventually fail. A structural engineer should evaluate immediately.[3]
Visible separation between foundation and structure: If daylight is visible between the top of the foundation and the bottom of the wall framing, the building has shifted. Do not enter without professional clearance.
Leaning or bowing exterior walls: Stand at one corner and sight along the wall. If it curves or leans noticeably, the structural framing may be compromised. Do not enter.
Diagonal cracks from window and door corners: Indicate racking (the building shifting from its square position). Common after earthquakes and high-wind events.
Separation at joints: Where walls meet ceilings, where additions meet original construction, or where the chimney meets the house. Gaps indicate differential movement.
Doors and windows that no longer open or close: Frames have been distorted by structural movement. This alone does not mean the building is unsafe, but it indicates the structure has shifted and should be evaluated.
Missing shingles or roof covering: Reduces weather protection but may not indicate structural failure. Tarp immediately to prevent water intrusion.
Sagging ridge line: The peak of the roof should be straight when viewed from the end. A visible sag indicates the ridge board or rafters may be compromised.
Visible daylight through the roof from inside: Structural members have separated or been removed by wind. Do not stand under this area.
Chimney leaning away from the house: An earthquake or wind event can separate the chimney from the structure. A leaning chimney is a collapse hazard. Stay clear until it has been assessed and do not use the fireplace.
Beyond structure
If you smell rotten eggs or hear hissing, leave immediately. Do not use light switches, matches, or phones inside. Turn off gas at the external meter if safe to do so. Call your gas utility from outside the building.
Do not restore power until the system has been inspected by a licensed electrician. Water-damaged wiring, submerged outlets, and damaged panels create electrocution and fire risks. If you see sparking, smell burning, or see scorch marks, the system is compromised.
If you are using a generator, never run it inside the house, garage, or any enclosed space. CO poisoning kills more people after disasters than many people realize. Generators go outside, at least 20 feet from windows and doors, with exhaust pointing away from the building.[4]
Floodwater may contain sewage, chemicals, fuel, and biological contaminants. Do not wade through standing water if you can avoid it. If the water system was compromised, do not drink tap water until authorities confirm it is safe.
Broken glass, exposed nails, splintered wood, and fallen building materials create injury hazards. Wear hard-soled boots, long pants, and work gloves. Ensure your tetanus vaccination is current.
Displaced animals, including snakes, may have entered the building. Check before reaching into dark spaces, cabinets, or debris piles.
The professional assessment
A structural engineer is a licensed professional who evaluates the load-bearing capacity and integrity of a building. This is a different role than a general contractor, home inspector, or building code official. After a disaster, a structural engineer provides the authoritative determination of whether your home can be safely occupied, what needs repair, and how to repair it.[5]
Hire a structural engineer if you observe any of the following: horizontal foundation cracks, bowing or leaning walls, visible separation between the foundation and structure, sagging roof or floors, shifted framing, or if your building was in the direct path of a tornado, earthquake, or landslide. A general contractor cannot make structural safety determinations; an engineer can.
A structural engineer's inspection and report for a residential property typically costs $350 to $800. Foundation-specific investigations run $400 to $1,500. These costs are separate from any repair work. The report is essential for insurance claims and for any repair permits your local building department may require.[5][6]
After the inspection
A structural engineer's report documents the current condition of the building, identifies specific damage, separates cosmetic issues from structural concerns, and recommends repairs. The report distinguishes between damage that can be monitored over time and damage that requires immediate action.
The report will note what the engineer could not see (finished walls, inaccessible crawl spaces, areas blocked by debris) and may recommend further investigation in those areas. Do not interpret a clean report on visible areas as a guarantee that hidden damage does not exist.
Keep the report. Your insurance company will need it to process structural damage claims. Your contractor will need it to scope repairs. Your local building department may require it before issuing repair permits. If you later sell the property, disclosure of the disaster and the engineer's findings may be legally required.
Before the next one
A structural assessment after a disaster is dramatically easier when you know what your home looked like before. Photograph the exterior and interior of your home, including the foundation, crawl space, and attic, and store the images in your household document kit. Pre-disaster photographs establish the baseline that engineers, adjusters, and contractors compare against.
Planning and document preparednessRelated recovery guides: Physical Recovery hub · Water and mold damage · Filing insurance claims · FEMA Individual Assistance
Sources
Last verified: June 2026. Structural assessment guidance is based on the ATC-20/ATC-45 standards and current professional engineering practice. Building codes and inspection requirements vary by jurisdiction.