July 2002 (Palm Springs, Calif) — The California Real Estate Inspection Association (CREIA) wants homebuyers and home sellers to know that professional inspectors are concerned about your home and may often recommend seismic safety upgrades in their reports.
Usually, recommended seismic upgrades by a professional home inspector are offered as suggested improvements, not mandatory requirements (with the exception of strapping of water heaters, there is no state law requiring a seller to bring an older home into compliance with current earthquake resistance requirements). However, seismic improvements are prudent and, if done properly, can significantly limit structural damage in the event of a severe earthquake.
Many property owners have chosen to reinforce their foundation systems against earthquake damage, especially since major quakes have occurred in California in the past decade and seismic upgrades were found to be very effective in homes which had been reinforced prior to those events. In most cases, effective seismic upgrading consists of following basics:
- Installation of additional anchor bolts to provide adequate attachment of the wood sills to the concrete foundation. This is only necessary when the existing bolts do not meet current building standards.
- Addition of plywood sheets, known as shear panels, nailed to the "cripple walls" to prevent collapse of those walls when lateral seismic forces are exerted against the building. Cripple walls are the short framed walls that extend from the top of the foundation to the base of the floor structure.
- Placement of hold-down brackets to secure "cripple walls" to the anchor bolts. This ensures that the wall studs will not separate from the wood sills when a quake occurs.
- Reinforcement of post and beam connections with plywood gussets or T-straps to ensure against separation or displacement.
In many homes, the floor joists are installed directly on the sill plates, rather than on "cripple walls." In such cases, the second and third recommendations above do not apply. Instead, tie-down brackets can be added to ensure secure attachment of the floor structure to the wood sills.
The average cost for these improvements is usually about $1,500 to 3,000 for a typical 3 bedroom home, but prices can vary greatly, depending upon the size, age and location of the building, as well as the type of construction. To ensure optimum reinforcement, it is recommended that the specifications for upgrading any building be determined by a licensed structural engineer.
This real estate bulletin has been brought to you by the California Real Estate Inspection Association. Since 1976, CREIA, a non-profit voluntary membership organization has been providing education, training, and support services to the real estate inspection industry and to the public. Inspectors must adhere to CREIA's Code of Ethics and follow the Standards of Practice developed by the association. These Standards of Practice have been recognized by the State of California, and are considered the source for Home Inspector Standard of Care by the real estate and legal communities.
CREIA requires its members to successfully pass a written test of property systems and complete 30 hours of education each year. Members can accumulate credits through various sources of education including monthly chapter meetings, conferences, and other approved activities. CREIA keeps records to ensure that members are complying with the requirements. Educational topics cover a variety of technical subjects including updates and advances that affect property inspection and the business of real estate inspection. CREIA is dedicated to consumer protection and education. To locate a qualified CREIA inspector near you, click here.