Asking an Earthquake Retrofit Contractor The Right Questions
Deciding who to hire is the most important decision you will make. Your retrofit is only as strong as the knowledge and skill of the contractor who does the work. One thing we know for sure – the earthquake will let you know if you hired the wrong one.
Is he familiar with?
California’s retrofit guideline “Appendix Chapter A3” and know who wrote it?
The exhaustive 290 page guidelines FEMA P-1100 290 PAGEVULNERABILITY BASED SESISMIC ASSESSMENT AND RETROFIT OF ONE AND TWO STORY DWELLINGS
The 422 Page Research Report for the “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings”
Seattle’s “Project Impact Retrofit Guidelines”
Los Angeles Department of Building and Safety Standard Plan Number 1
The Bay Area’s regional retrofit standard “Standard Plan A” and its many flaws
“Earthquake Strengthening of Cripple Walls in Wood Frame Dwellings”. A guideline published by the Federal Emergency Management Agency after the Napa earthquake.
The California Historic Building Code
Does Your Earthquake Retrofit Contractor Know About These Research Labs and Testing Facilities?
The American Plywood Association tests shear walls (every retrofit has shear walls) in Canada and the United States.
The American Wood Council which published the crucial Special Design Provisions for Wind and Seismic?
The International Staple Nail and Tool Association. Tells a seismic retrofit contractor everything there is to know about fasteners used in seismic retrofits.
These tests done by the Structural Engineers Association of Southern California in 1992. They demonstrated that low-quality foundations without steel reinforcing perform quite well in earthquakes.
Other Information Seismic Retrofit Contractors Should Know.
Ask your contractor if he thinks brackets on posts are a good idea. A lot of them recommend this wasteful procedure.
Does your earthquake retrofit contractor know about the 4 methods used in building retrofit shear walls?
Is your contractor familiar with old building code provisions that specify the strength of existing structures? If you don’t know how resistant a building already is, you can’t know where to address the weaknesses. These code provisions are found in Table A4-A of the International Existing Building Code.
How to address brick foundations? Guidelines for the Seismic Retrofit of Existing Buildings.
