Seismic Strapping - InspectionNews

Tony Escamilla · #1 (**permalink**) 05-07-2007, 09:04 AM

Can anyone tell me if the water heater seismic staps are required to encircle the heater? The plumbing code makes no reference. I know the metal strap kits are desgned to wrap completely around, but the straps in question are the nylon straps (look like automobile seat belts).

Richard Moore · #2 (**permalink**) 05-07-2007, 12:28 PM

Tony,

Here's a good pictorial from San Diego. http://www.sandiego.gov/development-...etin/ib207.pdf

Not all metal straps have to fully encircle the water heater. I think it depends on the strap design and the location of the supporting studs.

As for nylon straps, I've heard of them but never seen any (we shake up here too). I have seen a couple of sites that mention that the strapping is "required" to be metal but neither quote any code. One site mentioned the possibility of nylon strapping melting in a fie, but it would seem you already have a major problem if that occurs. You probably need to check with your AHJ to see if nylon is acceptable, and then with the manufacturer for installation instructions.

Failing that, use your noggin. Would the water heater be able to move significantly or not with the current straps and attachment points?

Richard Moore · #3 (**permalink**) 05-07-2007, 12:58 PM

Digging a little deeper into your state's requirements I found this in several places.

The State of California requires that all water heaters be strapped to resist motion during an earthquake. This may be accomplished by installing an over the counter “water heater restraint” kit approved by the Office of State Architect (O.S.A.).

and...

Some manufacturers make listed straps for water heater installations. Listed bracing straps may be used in lieu of the above methods when installed per the manufacturer's installation instructions.

(My bold)

None specifically mention that OTC "strap kits" need to be metal.

Tony Escamilla · #4 (**permalink**) 05-07-2007, 01:00 PM

Richard,

Thanks for the response. I did a bit more research. The plumbing code makes no mention one way or the other. I found the manufacturer of the straps. They are approved by IAPMO (the code publisher) for use in California and are to be installed per the manufacturers instructions.

I had the company email me the instructions and the are okay without going completely around the heater. Here is the link to the company: Hubbard Enterprises: Pipe Support Systems.

Richard Moore · #5 (**permalink**) 05-07-2007, 01:09 PM

Cool!

Here's a more direct link to those straps.

QB-120-F

Jerry Peck · #6 (**permalink**) 05-07-2007, 08:21 PM

Quote:

Originally Posted by Richard Moore

Tony,

Here's a good pictorial from San Diego. http://www.sandiego.gov/development-...etin/ib207.pdf

Not all metal straps have to fully encircle the water heater. I think it depends on the strap design and the location of the supporting studs.

Richard,

Those drawings show the straps, all of them, encircling the water heaters.

The top drawing shows the bottom strap encircling the water heater with one end connected to itself, with the other end secured to a stud.

The lower drawing shows both straps encircling the water heater.