Seismic anchoring / strapping is currently required on all water heaters in California as a health and safety requirement. However, the requirements differ from city to city. The minimum requirements for individual cities generally fall into two categories:

1. State of California minimum requirements (1994 Uniform Plumbing Code) and
2. California State Architects Office Requirements.

Brief History:

The state of California implementeda law in January 1996, requiring that the water heater tanks in homes being sold in the state had to be braced / anchored to guard against seismic movement. The law requires that the bracing was to be provided by sellers for the buyers of the properties and to be done consistent with the State Architects Specifications. The law was amended in July of 1996 to identify the 1994 Uniform Plumbing Code seismic strapping requirements as the minimum state requirement.

The State of California minimum requirements:

requires water heaters to be anchored or strapped to resist horizontal displacement due to earthquake motion as per specified in the 1994 Uniform Plumbing Code. Strapping shall be at points within the upper one-third (1/3) and lower one-third (1/3) of its vertical dimensions. At the lower point, a minimum distance of four (4) inches shall be maintained above the controls with the strapping. State Architects Office seismic strapping provisions, effective January 1996 has varied means of securing a water heater tank. It is commonly accomplished by providing a metal strap wrapped around both the upper and lower sections of the tank and located approximately 1/3 down from the top and 1/3 up from the bottom, respectively. These need to be bolted into the adjacent wall / framing with lag bolts. Provisions for support of the back of the tank are required and may need to be of a non-combustible material (see the labels on your specific tank that identifies minimum distances to combustible materials). Tanks larger than 50 gallons may require additional strapping (75 gallon tank requires 3 straps). For more specific information and diagrams, refer to the Office of the State Architect (916-324-5315).