Earthquake strap all water heaters? - InspectionNews

Matt Fellman · #1 (**permalink**) 12-12-2007, 10:24 PM

Is there any exception for earthquake strapping those short, squatty tanks? I seem to see a lot of them under stairs in townhouses or in lower kitchen cabinets in apartments.

Or, how about tanks that are enclosed with an access panel that is secured in place, like you often find in a manufactured home.

mike huntzinger · #2 (**permalink**) 12-13-2007, 01:02 PM

straps required but on demand or tankless do not

Jerry Peck · #3 (**permalink**) 12-13-2007, 04:08 PM

Quote:

Originally Posted by mike huntzinger

straps required but on demand or tankless do not

From the 2006 IRC.
- P2801.7 Water heater seismic bracing. In Seismic Design Categories D

0

, D1 and D2 and townhouses in Seismic Design Category C, water heaters shall be anchored or strapped in the upper one-third and in the lower one-third of the appliance to resist a horizontal force equal to one-third of the operating weight of the water heater, acting in any horizontal direction, or in accordance with the appliance manufacturer’s recommendations.

I don't see any exception in there for other-than-"storage" *water heaters*. I know the intent is to keep that heavy thing in place, nonetheless, though, a "water heater" is a "water heater".

Dom D'Agostino · #4 (**permalink**) 12-13-2007, 05:28 PM

Quote:

Originally Posted by Jerry Peck

From the 2006 IRC.
- P2801.7 Water heater seismic bracing. In Seismic Design Categories D

0

, D1 and D2 and townhouses in Seismic Design Category C, water heaters shall be anchored or strapped in the upper one-third and in the lower one-third of the appliance to resist a horizontal force equal to one-third of the operating weight of the water heater, acting in any horizontal direction, or in accordance with the appliance manufacturer’s recommendations.

I don't see any exception in there for other-than-"storage" *water heaters*. I know the intent is to keep that heavy thing in place, nonetheless, though, a "water heater" is a "water heater".

There's your answer, Jerry. No strapping needed if the manufacturer addresses "anchoring" in their installation instructions.

Jerry Peck · #5 (**permalink**) 12-13-2007, 06:57 PM

Quote:

Originally Posted by Dom D'Agostino

There's your answer, Jerry. No strapping needed if the manufacturer addresses "anchoring" in their installation instructions.

Which also applies to *any* storage water heater too.

Sorry to set that up like I did, but if a "storage" type water heater's installation instructions "also" do not call for that strapping, then, by that same statement ... no strapping is required.

Because that is an "or" in there instead of the usual "and".

Rick Cantrell · #6 (**permalink**) 12-14-2007, 05:48 AM

I have one of the "instant on" or " tankless" water heaters, in my office. It has 4 mounting (anchor) points, one at each corner, and weighs about 3 lbs.
I think this meets the requirments of P2801.7 There should be no need for any additional anchors or strapping, at least for the water heater I have.

"P2801.7Water heater seismic bracing. In Seismic Design Categories
D0,D1 andD2 and townhouses in Seismic Design Category C, water heaters shall be anchored or strapped in the upper one-third and in the lower one-third of the appliance to resist a horizontal force equal to one-third of the operating weight of the water heater, acting in any horizontal direction, or in accordance with the appliance manufacturer’s recommendations."

So Jerry is correct in saying "I don't see any exception in there for other-than-"storage" *water heaters*. ".
While at the same time Mike is also correct in saying
"straps required but on demand or tankless do not".

Dana Bostick · #7 (**permalink**) 12-14-2007, 10:49 AM

Not very many of my clients complain about being told to strap now days. It's pretty much a given. The problem is in HOW to strap. What standard do they follow? the Gas Compny says one thing, the B&S another, the code another and the California State Architect's office even allows using P-tape! I'm confused. LOL, not my problem though anymore since I don't do any installs or repairs. We have "retrofitting" company's that handle all that stuff and they get to sort out the confusion.

I just explain the concept of inertia and 500+ pounds of WH and tank standing tall and what might happen if it's not well secured. I don't bother with the little guys unless they are mounted up high on a shelf like in many commercial locations with remote bathrooms like in a wherehouse.

Experience is the thing you have left when everything else is gone.

Jerry McCarthy · #8 (**permalink**) 12-14-2007, 12:03 PM

California requires it as most of the population live in high seismic zones. See CA Bldg. code for the zone you live and inspect in and I'll bet it will require approved strapping regardless of Mfg. instructions. The State Architect has a really FUBAR instruction sheet of what they believe to be adequate strapping.

Gunnar Alquist · #9 (**permalink**) 01-18-2008, 03:57 PM

OK,

Hoping people from CA use the "New Posts" button to view posts.

I just had a call from someone who wanted to know if brackets are acceptable for water heater strapping. In this case, the water heater was attached with a bracket at the top of the tank and plumbers' tape around the base. The bracket in question is an adjustable "Y" shaped metal bracket that attaches to the inlet and outlet supply pipes at the top of the tank and is lag bolted to a single stud. The plumbers' tape was nicely bolted to two studs (instead of just nailed), but not in compliance with the Division of the State Architect.

I have been unable to find this type of bracket for sale (which would indicate to me that it does not meet current requirements). It also does not address attachment of the base of the tank. It would be necessary to provide a strap in order to conform with current requirements. I feel that they need to just get a new strap kit and have done with it.

Anyway, CA inspectors, what say you?

Jerry Peck · #10 (**permalink**) 01-18-2008, 05:35 PM

Quote:

Originally Posted by Gunnar Alquist

The bracket in question is an adjustable "Y" shaped metal bracket that attaches to the inlet and outlet supply pipes at the top of the tank ...

Not from CA, but ... "attaches to the inlet and outlet supply pipes " - that's not kosher, is it?

If there is an earthquake, the weight of the tank will break those pipe right off - you need to be strapping the actual tank ... right?

Gunnar Alquist · #11 (**permalink**) 01-18-2008, 06:00 PM

Jerry,

Yes, that is my opinion as well. However, the brackets were manufactured and (presumably tested/listed) for this specific purpose, so...

However, the bracket is attached at one point only, which could allow the tank to rotate around that point in an earthquake. It seems to me that this would give the tank leverage over the attachment point, which would be more likely to fail. Straps are anchored in two locations, which if done properly (they rarely are) would limit lateral movement.

Thanks for the response, even if it is from hurricane country and not earthquake country.

Jerry McCarthy · #12 (**permalink**) 01-18-2008, 07:18 PM

Every jurisdiction in CA that I know of has long ago adopted the DSA protocol for approved seismic strappinng of water heaters, which in my opinion is bogus to say the least. Their web site shows a photo of what they claim is a classicically strapped water heater, which ain't plus a couple of other obvious CA code defects.

DSA - Department of the State Architect Hmmmmmmm ?

Jerry Peck · #13 (**permalink**) 01-18-2008, 08:37 PM

Quote:

Originally Posted by Gunnar Alquist

Yes, that is my opinion as well. However, the brackets were manufactured and (presumably tested/listed) for this specific purpose, so...

Gunnar,

This is from above, don't know how much the CA code differs (I am using Rick's post because his highlighting with bold is applicable to your question and installation).

Quote:

Originally Posted by Rick Cantrell

"P2801.7 Water heater seismic bracing. In Seismic Design Categories D0,D1 and D2 and townhouses in Seismic Design Category C, water heaters shall be anchored or strapped in the upper one-third and in the lower one-third of the appliance to resist a horizontal force equal to one-third of the operating weight of the water heater, acting in any horizontal direction, or in accordance with the appliance manufacturer’s recommendations."

Does not say anything about "the bracket" manufacturer's instructions, just 'the upper and lower 1/3' and "the appliance" manufacturer's instructions.

In my opinion, 'the hot and cold supply' does not fall into "in the upper one-third", the hot and cold supplies would fall 'above' the upper 1/3.

Gunnar Alquist · #14 (**permalink**) 01-19-2008, 12:18 PM

Jerry Mc.

Not sure what photo you are referring to. I have downloaded the 12 page pdf instruction sheet and the strapping seems fine to me. Better than most actual kit installations that I see.

http://www.documents.dgs.ca.gov/dsa/...g_11_30_05.pdf

Jerry P.

I agree. One of my problems is that I end up in discussions with plumbers and agents regarding "proper" strapping and I tend to go back to the CDSA as well as the installation instructions from the strap manufacturers. I had forgotten the code (slap) requirements.