Thursday, April 4, 2013

Seismic Safety - Water Heater Welfare

Every year we do several structural assessments of commercial and residential buildings.  Often, we see hot water heaters that do not have adequate seismic restraint.  This is something that is easily overlooked during construction or water heater replacement.  Unrestrained water heaters have broken loose or toppled creating serious threats of fire, explosion and electrocution in past earthquakes.

Unanchored Water Heaters Overturned During a Seismic Event
California has adopted Health and Safety Code Sections 19210-19217 to address these life safety threats.  The code states that:
  • Any new or replaced water heater sold on or after July 1, 1991 shall be braced, anchored or strapped to resist falling or horizontal displacement due to earthquake forces. 
  • The seller of any real property containing a water heater shall certify to the prospective purchaser that this section has been complied with. 
  • All water heaters manufactured for sale in California on or after July 1, 1991, shall include a statement in the instructions that the water heater must be braced, anchored or strapped to resist falling or moving. 
  • The front of the water heater shall have a label that states:                                               Warning: This water heater must be braced, anchored, or strapped to avoid falling or moving during an earthquake.  See instructions for correct installation procedures.

Since this issue affects every building owner and tenant in California, the Division of State Architects (DSA) has prepared some generic seismic restraint details.  The DSA details utilize two methods of bracing material:
  • Plumbers Tape Bracing
  • EMT Conduit Bracing
Water Heater Bracing Example, Division of State Architects
See DSA installation instructions

 The DSA details do not apply to every situation, but they are a minimal guide to start with.  There are other manufactured systems available.  Their installation instructions should be complied with.  We also suggest that you consult with a licensed Structural Engineer for any atypical situations or if you questions/concerns regarding your current water heater seismic restraint.  Remember, a loose water heater is a dangerous water heater!


No comments:

Post a Comment