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#188943 09/11/09 04:50 PM
Joined: Dec 2001
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How can you tell if this plywood is UL listed?

(Click on thumbnail image)

[Linked Image from electrical-photos.com]

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Perhaps a flame spread test?



John
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A very ... interesting .... way to remodel a bath! Perhaps the last panel rusted apart?

Irreverent comment follows: There actually IS such a thing as "UL Listed plywood!" UL does list some plywood for surface fire resistance, as evaluated by a flame-spread test (E-84).

Still ... the UL standard for panels states plainly at its' beginning (materials) that wood shall not be used in the construction.

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Reno:
What you are refering to is 'FRP" rated/labeled plywood. That's the designation 'grade stamp on each sheet, I do not know if 'FRP' is the UL nomenclature.



John
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The only FRP I know about is "Fiberglass Reinforced Panel". The stuff I saw was more of a plastic thing than plywood.
They use it in commercial kitchens and public bathrooms in tough spots. It handles hosing down well. I am not sure about flame.


Greg Fretwell
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that second link looks like what they make those industrial freezers out of


-Joe
“then we'll glue em' then screw em'”
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JoeKP #188977 09/14/09 02:04 AM
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No, Hotline, I am NOT referring to FRP, or the partitions they have inside gear.

I am describing actual, ordinary plywood that has been pressure-treated for fire resistance. It does exist - good luck finding it, though!

The UL label oneach sheet will contain numbers representing ratings for flame spread and smoke developed. You can find similar labels on rolls of household insulation.

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Reno,

The first link I posted above leads to all the information on type FRS fire resistant plywood, including a picture of the labeling.

It's commonly required for telco backboards in the 3/4" size, as well as specified for the mounting of electrical equipment & is readily available.

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Yes, it does, Scott! And, yes, telco backer boards is exactly where I have encountered the specification.

I had inferred that the other comments thought I was referring to the red-fiber stuff you find in switchgear. That "FRP" stuff commonly found in commercial kitchens is another material altogether.

Thanks for the good links!

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