Earthquake straps on a Washington water heater

Are water heater earthquake straps required in Washington?

Yes. Section 507.2 of Washington's amendments, in WAC 51-56, says water heaters "shall be anchored or strapped to resist horizontal displacement due to earthquake motion." The code took effect in every city and county on March 15, 2024, and the State Building Code Council still lists that 2021 edition as current. A 2024 update is moving through proposed rules in 2026, so check the WAC again if you read this much later.

Where do the straps go on the tank?

Picture the tank split into thirds from floor to top. One strap goes somewhere in the upper third and one in the lower third. At the lower strap, keep at least 4 inches between the strap and the controls, whether that's an electric thermostat cover or a gas control. That clearance keeps the strap from crushing or blocking parts that need service.

What does a correct strap job look like?

Washington's Emergency Management Division home hazard hunt asks whether the heater is fastened to the wall studs with heavy metal strapping at the top and bottom, and says not to use metal plumber's tape. FEMA's home hazard hunt poster suggests a strap or bracing kit from a hardware store, or a licensed plumber who straps to code. Signs of a good job:

• Straps wrap the tank and anchor into studs or blocking, not drywall alone.
• No slack: a firm push doesn't rock the tank.
• Nothing presses on the drain valve, relief valve or access panels.

Why does strapping matter so much here?

The Washington DNR homeowner's earthquake guide calls a free-standing, unsecured water heater one of the most unstable appliances in a home. In strong shaking it can topple and break gas and water lines, causing flooding or fire. A tank holding tens of gallons is heavy, and it sits on the line that feeds your whole house, in a garage, closet or crawlspace.

Do the connections need to be flexible?

The Emergency Management checklist asks whether the heater has flexible water and gas connectors, and FEMA notes flexible connectors are safer than rigid pipe during an earthquake. If your gas or propane heater has a rigid gas pipe, that is a question for a licensed plumber; don't loosen, bend or swap any gas fitting yourself. If you smell gas, use no switches or flames, leave, and call 911 and your gas utility or propane supplier from outside.

Who should install the straps?

Washington lets property owners do plumbing on their own property, while L&I's plumber program limits work on someone else's property to certified plumbers. Strapping an existing tank to studs is mostly carpentry, and many owners use a kit. A new or replacement heater is different: straps are part of the install, and in Thurston County that install usually goes through a permit, as the water heater stop explains. The inspector will look for them.

Yours to do

• Check the straps once a year and after any shaking.
• Push the tank gently to see if it rocks.
• Measure the gap between the lower strap and the controls.
• Keep stored items from leaning on the tank.

Leave to a licensed or certified pro

• Strapping a new or replacement heater as part of a permitted install.
• Any change to a rigid gas connection.
• Adding blocking where there's no stud to anchor into.
• Re-setting a tank that has shifted or leaks at a fitting.

On the record

• 2 strapsone in the upper third, one in the lower thirdWAC 51-56
• 4 inchesminimum gap from the lower strap to the controlsWAC 51-56
• March 15, 2024strapping rule in force in every Washington city and countyWAC 51-56-008
• Once a yearhow often FEMA suggests checking the strapsFEMA 528

Common questions

Does an old heater that was never strapped need straps now?

Section 507.2 applies to water heaters with no age cutoff, and the state's hazard checklists treat any unstrapped tank as a hazard. Adding straps to an existing tank helps limit the chance it tips in shaking.

Is plumber's tape good enough?

No. The Emergency Management checklist says not to use metal plumber's tape and calls for heavy metal strapping instead.

Do tankless heaters need straps?

The code language names water heaters in general. Wall-hung units mount to the wall by design; follow the maker's mounting instructions and ask your permit office if unsure.

Will a home inspector look at the straps when I sell?

A buyer's inspector may note missing straps, and adding them first is a small job. The buying and selling page covers what else a buyer may ask for.

Can the strap go across the gas control?

No. The rule calls for at least 4 inches between the lower strap and the controls.

Sources

1. WAC 51-56, Washington amendments to the 2021 Uniform Plumbing Code — section 507.2 strapping rule and statewide effective date; read 6 November 2026
2. Washington State Building Code Council — 2021 codes effective March 15, 2024; 2024 cycle at proposed-rule stage; read 6 November 2026
3. Washington Emergency Management Division, Home Hazard Hunt — heavy metal strapping to studs, no plumber's tape, flexible connectors; read 6 November 2026
4. Washington DNR homeowner's guide to earthquakes — unsecured heaters topple and break lines; read 6 November 2026
5. FEMA 528 Earthquake Home Hazard Hunt — kits, licensed plumber, yearly strap check; read 6 November 2026
6. L&I plumber program — who may do plumbing work; read 6 November 2026

How this page was put together. This page rests on Washington's plumbing code amendments, the State Building Code Council's status page, L&I, Washington DNR, the state Emergency Management Division and FEMA, all read on 6 November 2026. It does not give strap brands, kit prices or gas connector steps, and it does not cover commercial or manufactured-home rules.