Seismic Straps on Water Heater: Building Codes & Who Needs Them

Source

Seismic straps are critical when using water heaters if you live in an earthquake-prone area. They prevent the water heater from tipping backward as the ground shifts. But there is a specific way to strap the straps onto the heater. It should be according to building codes. And that brings us to the question of how to strap a water heater.

Installing seismic straps on your water can prevent it from falling over or shifting during an earthquake or other seismic event. Most water heaters need a double body strap system, including one metal strap on the upper third of the unit and a second strap on the bottom third to hold it in place.

This guide looks at the importance of seismic straps, who needs them most, and how to use them to keep a water heater safe.

Which States Require Water Heater Seismic Straps?

Here is a quick look at the adopted plumbing codes and the water heater strap codes in each state. 

Note: The following is an overall look at the water heater codes by state. You must verify the specific requirements for your water heater with your local governing authority.

U.S. StateDo You Need Water Heater Seismic Straps?
AlabamaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Alaska At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Arizona At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Arkansas At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
California At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
ColoradoSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
ConnecticutSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
DelawareSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
FloridaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
GeorgiaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Hawaii At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Idaho At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Illinois Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: Illinois Plumbing Code
Indiana Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: UPC & the Indiana Plumbing Code
Iowa Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: UPC & IPC in some places
Kansas At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Kentucky At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: Kentucky State Plumbing Code
Louisiana Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: Louisiana State Plumbing Code
Maine Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: Maine Internal Plumbing Code
MarylandSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
MassachusettsCode does not mention water heater seismic straps. Add if needed per the UPC or IPC. Observes: Uniform State Plumbing Code
MichiganSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Minnesota Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: Minnesota Plumbing Code
Mississippi At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Missouri At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Montana At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Nebraska At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Nevada At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: IPC or UPC depending on location
New HampshireSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
New Jersey Code does not mention water heater seismic straps. Add if needed per the UPC or IPC. Observes: NSPC
New Mexico At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: New Mexico Plumbing Code
New York At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
North Carolina At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
North DakotaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
OhioSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Oklahoma At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
Oregon At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: Oregon Speciality Plumbing Code
PennsylvaniaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Rhode IslandSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
South Carolina At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
South Dakota Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: UPC
Tennessee At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3.
TexasSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Utah At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes:
VermontSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
VirginiaSeismic straps are typically not mandatory. Must anchor unit to withstand a force equal to at least 1/3 of its weight.
Washington At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: UPC
West VirginiaSeismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: IPC
Wisconsin Seismic straps are typically not mandatory. Anchor unit to withstand a force equal to at least 1/3 of its weight. Observes: Wisconsin Statutes, Comm 81-87, Plumbing Code
Wyoming At least two 22-gauge metal straps. One strap on the top 1/3 of the unit and one on the bottom 1/3. Observes: IPC

States that Experience Low to Zero Seismic Activity

  • Alabama
  • Colorado
  • Connecticut
  • Delaware, Florida
  • Georgia, Maryland
  • Michigan
  • New Hampshire
  • North Dakota
  • Ohio
  • Pennsylvania
  • Rhode Island
  • Texas
  • Vermont
  • Virginia
  • West Virginia (IPC)
  • Illinois (Illinois Plumbing Code)
  • Indiana (UPC & the Indiana Plumbing Code)
  • Iowa (UPC & IPC in some places)
  • Louisiana (Louisiana State Plumbing Code)
  • Maine (Maine Internal Plumbing Code)
  • Minnesota (Minnesota Plumbing Code)
  • South Dakota (UPC)
  • Wisconsin (Wisconsin Statutes, Comm 81-87, Plumbing Code)

These states experience little to no seismic activity. The standard code requires water heater straps only when necessary to handle any applicable seismic forces. You must anchor the unit to withstand a force equal to 1/3 the operating weight of the water heater.

States that Experience Mid to Hight Levels of Seismic Activity

  • Arizona
  • Arkansas
  • Kansas
  • Mississippi
  • Nebraska
  • New York
  • North Carolina
  • Oklahoma
  • South Carolina
  • Tennessee
  • Utah
  • Wyoming (IPC)
  • Alaska
  • California
  • Hawaii
  • Idaho
  • Missouri
  • Montana
  • Washington (UPC)
  • Kentucky (Kentucky State Plumbing Code)
  • Nevada (IPC or UPC depending on location)
  • New Mexico (New Mexico Plumbing Code, based on the UPC)
  • Oregon (Oregon Speciality Plumbing Code, based on the UPC)

In zones with mid to high seismic activity, you need to use two metal straps, at least 22 gauge. One strap must be within the top 1/3 of the unit and the second strap within the bottom 1/3.

The bottom strap must be at least 4 inches above the water heater’s controls. The straps must be secured with screws at least 1/4″ x 3″ long and penetrate at least 1.5″ into the wall studs.

States that Do Not Mention Water Heater Seismic Straps

  • Massachusetts (Uniform State Plumbing Code)
  • New Jersey (NSPC)

The code for these states makes no specific mention of requiring water heater straps. If the unit is in a region of mid to high seismic activity, you should install straps following the UPC or IPC.

Why Do You Need Seismic Straps On a Water Heater?

Source

Here are reasons why you will need seismic straps on a water heater. 

1. They Keep the Water Heater Cylinder In Place

During an earthquake, the ground shifts, seismic straps are specifically for holding the water heater in place. That makes anything that is not strapped into place a falling hazard, including water heaters. 

Earthquakes tend to cause more property damage than human-based injuries. However, during an earthquake, human injuries are sustained mainly from falling objects. If you live in an earthquake region, it is probably second nature for you to anchor or brace large objects in your home during a quake, including a water heater. Seismic straps are specifically for holding the water heater in place.

A standard residential water heater can weigh between 450 and 500 pounds when at full capacity. Plus, these cylindrical tanks are unstable because they have a high center of gravity. The combination of weight and lack of stability makes them prone to falling over easily.

2. Federal Law Mandates Them

The Uniform Plumbing Code has required the installation of seismic straps on water heaters since 1982.

This mandate is to keep water heater users safe. A falling water heater may cause an explosion, fire, or water damage. That is likely to occur during an earthquake, storm, or another event that destabilizes the structure.

The federal government made seismic straps mandatory after the 1994 Northridge earthquake of San Fernando Valley. The quake measured a magnitude of 6.7 on the Richter scale. But most importantly, the officials counted at least ten infernos across the affected region that were a direct result of toppled water heaters. 

The 1989 Loma Prieta earthquake also had a similar issue with toppled water heaters. The magnitude of this earthquake was 6.9.

In both cases, some owners had completely not strapped their water heater in place. Others had strapped their units using substandard materials like plumber’s tape, while others had only secured the heaters with one strap. But, it is essential to note that there was no uniform code governing the water heaters’ strap.

x
Why Home Inspections Are Important

Water heaters burst through all these fastenings and fell over, rupturing gas and water connections damaging individual and neighboring properties.

The government-mandated specific seismic straps and provided clear instructions on securing the straps onto the wall.

How Do You Strap Down a Free Standing Water Heater?

You can buy commercial strapping kits that take the work out of looking for lag screws, spacers, washers, and other components.

Strapping a Free-Standing Water Heater 

  1. Measure the six inches from the top of the water heater and make a mark because this is where the top strap will go.
  1. Next, measure 18 inches from the bottom of the heater and mark the spot. That is where the bottom strap will fasten.
  1. Drill holes into the wall for the lag bolts at each of the marks.
  1. Stand the heater vertically and place it snugly next to a wall. 
  1. For the best anchoring, ensure the heater sits directly in front of the 2×4 inch wall stud.
  1. Using screws, attach four strap fasteners onto the wall studs in front of the heater.
  1. Follow the manufacturer’s instructions on cinching the straps in place.
  1. After you cinch straps, ensure that you inspect them to ensure they are completely secure and will hold the tank. Adjust as necessary if not.

The kit comes with all the needed components making it easier to strap the heater. The installation should be per building codes.

DIY Method for Strapping a Free-Standing Water Heater

  1. You need to have two straps going around the unit, and they should be secured onto the wall’s masonry.
  1. Place the water heater near the wall leaving very little clearance between the unit and the wall.
  1. Wedge a wooden block to the wall studs to eliminate the space completely and for a snug fit. That will help prevent the unit from tipping backward.
  1. It would be best if you had heavy-gauge metal strapping to go around the heater 1 ½ times. You can buy it at the local hardware store. Place the strapping on the back of the heater tank and then bring it to the front before returning it to the back again.
  1. Once the strap is back behind the tank, secure it to the wooden block. Make sure the wooden block is bolted onto the wall studs. Anchor the heater using long lag screws that have oversized washers.
  1. If you prefer to anchor the water heater directly into a concrete wall, it is best to use quarter-inch expansion bolts to secure it.

On top of installing the straps, you can install corrugated supply lines that are flexible enough to bend according to the quake’s movement.

Does Your Water Heater Need Seismic Straps?

There are many reasons why the government mandates seismic straps for water heaters in many areas. Before 1991, there was a lot of confusion about the seismic straps and whether water heaters needed them. 

Some of the points of contention included.

  • How many straps does one need to put on a water heater?
  • Can plumbing tape work?
  • Should the straps go all the way around the tank?
  • Do electric water heaters need straps in the first place?

Realtors, plumbing experts, home inspectors, and even some building departments have offered differing answers muddying the waters for homeowners.

Here is the deal:

The original code about water heaters only said that the units need anchoring or strapping to avoid horizontal displacement caused by an earthquake’s motion.

This generalization left the statement open to individual interpretation. And that is why so many questions arose. 

But individual states took it upon themselves to have state specifications, usually from the state architect’s office.

For example, in California, new legislation made it mandatory for all water heaters manufactured in California for sale since 1991 to have a statement in the installation guide mentioning that water heaters must be strapped, anchored, or braced to resist horizontal displacement during an earthquake.

According to the legislation, the manufacturer can provide generic details and installation instructions prepared by the Division of the State Architect under Section 19215. Manufacturers and retailers not providing strapping instructions violate the legislation.

The state’s specifications went into effect in 1992 and are the legal criteria for strapping water heaters in California even today. That means that you must strap down all water heaters in California using two straps.

But it doesn’t end there.

Several other states have adopted the legislation under the California Plumbing Code Section 507.2.

California is one of the hardest-hit earthquake regions in the United States, which would explain why. After all, San Fernando Valley and Loma Prieta are in Southern and Northern California, respectively.

That would explain why they require the strapping of water heaters. 

But that doesn’t mean that this is a universal legal requirement across the United States. You need to find out if this applies to your state from the building inspector or building department.

Who Needs Seismic Straps On Their Water Heaters?

The American Society of Civil Engineers (ASCE) is the authority on seismic protection of non-structural components. You can find the ASCE standard under the Minimum Design Loads for Buildings and Other Structures, also known as the ASCE 7.

According to the ASCE 7, buildings fall into seismic design categories (SDC). The categories range from A to F. 

Buildings categorized as A have little to no seismic concern to go without straps for their water heaters. Buildings in category F have the most concern and must have straps for their water heaters. To achieve the different categories, the ASCE takes into account:

  • Anticipated ground acceleration during a quake
  • Occupancy of the building (like hospitals, police stations, and fire departments)
  • Risk to human life.

These values are present in the engineering plans of your property or at the local building department.

It is best to determine what category your building falls under to decide whether or not you need seismic bracing for your water heater. Once you know your category, act accordingly by installing straps if you’re in a high or medium-risk area.

What Is The Code for Strapping a Water Heater?

The code governing the strapping of water heaters is the Uniform Plumbing Code (UPC). According to the UPC, bracing or strapping water heaters is advisable in some locations.

The Uniform Building Code (UBC) is more specific and detailed in the requirements expected for seismic bracing. It offers more insight on how to brace non-structural equipment like water heaters over 400 points. 

The UBC was used as a reference by the California Division of the State’s Architect mentioned above. The Uniform Building Codes helped inform the testing of strapping kits in California.

Does FHA Require Water Heater Straps?

The Federal Housing Administration (FHA) provides loans to lenders to help them purchase homes. And to get the loan, the property you intend to buy must meet the FHA requirements, which cover 

  • Heating and electrical components
  • Water heaters
  • Attics and roofs
  • Hazards like asbestos and contaminated soil
  • Appliances
  • Bathrooms
  • Structural soundness
  • Property access 

Concerning water heaters, the Federal Housing Administration does not enforce the building code requiring these units. It does, however, require that borrowers adhere to local laws about units like water heaters. 

For example, if the local laws mandate that you strap or anchor the water heater in place, the FHA will make this requirement part of their expectations.

In this scenario, the FHA is deferring to the local laws about water heaters for their requirements about giving you the loan.

For instance, the local county code may stipulate that you should strap a water heater using specific seismic straps, or there may be particular requirements for the pressure valve. Some may even have rules about whether the water heater should be on the ground or elevated.

Your FHA transaction will not be approved if you do not adhere to these local code requirements since the body conducts an appraisal inspection on the borrower’s properties.

If the property meets the requirements according to the form, the deal should go through. If not, you may have to settle for another property.

There are quite many water heater scenarios, and each has different requirements apply.

If you have questions about what water heater installation requirements apply to your building, it is best to reach out to the local building department. And it would be best if you did this before borrowing from the FHA.

Conclusion

Seismic braces limit horizontal shaking of non-structural equipment during an earthquake. 

Seismic straps must not only withstand but also resist the seismic forces bombarding them. That is why they should attach to structural components of the building like the walls. The braces will ensure the secured equipment moves with the building during a quake instead of tipping or falling over.

Not all buildings require water heaters to be strapped or anchored in place. Go to the building department near you to find out if this applies to your property.

Sources

HomeInspectionInsider.com is owned and operated by Hubert Miles is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. HomeInspectionInsider.com also participates in affiliate programs with other affiliate sites. Hubert Miles is compensated for referring traffic and business to these companies.

Hubert Miles

I've been conducting home inspections for 17 years. I'm a licensed Home Inspector, Certified Master Inspector (CMI), and FHA 203k Consultant. I started HomeInspectionInsider.com to help people better understand the home inspection process and answer questions about homeownership and home maintenance.

Recent Published Posts