What is FEMA P-1100?
FEMA P-1100, officially titled "Vulnerability-Based Seismic Assessment and Retrofit of One- and Two-Family Dwellings,” is a document designed to help California homeowners, engineers, architects, and building professionals evaluate, identify, and retrofit seismic vulnerabilities in wood frame dwellings, which are the most common types of homes in the United States. It was developed for the Federal Emergency Management Agency (FEMA) and California Earthquake Authority (CEA).
FEMA P-1100 addresses specific and well-known seismic vulnerabilities in construction and design that have caused many California homes to become uninhabitable after being damaged by earthquakes. Using the guidance outlined in this document may not prevent earthquake damage but could help increase your home’s earthquake resilience.
Key Components of FEMA P-1100
FEMA P-1100 introduces earthquake retrofitting techniques, strategies, and best practices that can make homes more earthquake resistant. They include:
- Retrofitting Recommendations: Detailed recommendations for retrofitting wood-frame residential homes, such as their foundation, cripple wall bracing, and roof-to-wall connections.
- Seismic Hazard Assessments: Guidance on understanding seismic hazards for specific types of homes and the damage that can be caused by earthquakes.
- Engineering Principles: Explanations of the engineering principles behind earthquake retrofits so that homeowners better understand the retrofit process.
- Cost Considerations: Information on estimating the cost of a California earthquake retrofit, including important budgeting considerations for your own seismic retrofit project.
- Vulnerability-based Assessments: Specific recommendations for addressing seismic weaknesses because retrofits are not like typical design and construction overhaul projects.
Which Common Vulnerabilities Does FEMA P-1100 Address?
FEMA P-1100 addresses seismic vulnerabilities commonly found in wood-frame residences, including one- and two-family detached houses, townhouses, and single-family homes that have been divided into multiple living units. Remember that every day is earthquake season in California, and using the guidance outlined in this document may not prevent earthquake damage but could help increase your home’s earthquake resilience.
Different types of homes have specific seismic vulnerabilities that may need to be addressed in a retrofit, including:
- Crawlspace or Raised Foundation Homes – anchor the home’s crawlspace to its foundation, bracing cripple walls, and bolting the house to its foundation to prevent the home from sliding off its foundation during an earthquake.
- Soft-Story Homes – brace the home’s ground story by installing new plywood sheathing or steel reinforcements on either side of the garage door, bracing studs and/or creating new shear walls in order to help these homes resist the side to side shaking that occurs during earthquakes.
- Hillside Homes – anchor hillside homes to their foundations and installing cripple wall bracing to help withstand the weight of the house bearing downhill and support the house’s entire structure.
- Homes with Chimneys – reinforce new masonry chimneys per the building code using proper mortar, vertical bars and anchor straps, or other methods to help prevent them from cracking, falling, or even completely collapsing due to earthquakes.
- Homes with Fireplaces – remove, anchor, or reinforce masonry fireplace surrounds to prevent them from cracking and/or falling during an earthquake, which can cause property damage and severe injury (or even death) to people nearby.
Implementing FEMA P-1100 Recommendations with CRMP
We can help you understand the complexities of FEMA P-1100 and assist you with many parts of your retrofitting project. We offer free resources, funding, and support to help California homeowners strengthen their homes by implementing FEMA P-1100 recommendations.
If you have questions about any part of the FEMA P-1100 process, please feel free to Contact Us for assistance.
CRMP Support for Implementing FEMA P-1100 Guidelines
The California Residential Mitigation Program (CRMP) was established in 2011 to provide grants and assistance to California homeowners who want to protect their homes against earthquakes.
Our goal is to help create a stronger and more resilient California by providing support to homeowners via two Earthquake Retrofit Grant Programs: the Earthquake Brace + Bolt (EBB) Retrofit program, and the Earthquake Soft-Story Retrofit program (ESS). Each of these align with FEMA P-1100 guidelines.
For assistance on starting your own retrofit project, check out our Next Steps: Retrofit Process page.
Every day is earthquake season in California. To try to further protect your home and your loved ones from earthquakes, please also read Preparing for an Earthquake, Creating an Earthquake Emergency Kit, and the 7 Top-Rated Earthquake Safety Tips.
Remember that earthquake preparedness can help protect property and save lives, and that the best time to start getting ready for the next big earthquake is well before the ground begins to shake!
Visit our Seismic Strong Blog for more tips, advice, and information about earthquakes.