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Re: Fasteners in Fire Resistant Treated Wood (FRTW)

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Thanks John.  My general notes indicate that all fasteners must be hot-dipped zinc-coated galvanized steel, stainless steel, silicon bronze, copper or other suitable corrosion-resistant material exhibiting corrosion rates less that 1 mil per year when tested in accordance with Federal Specification MIL-L-19140, par 4.6.5.2.  This spec is nearly identical to AWPA E12-94, Standard Method of Dermining Corrosion of Metal in Contact with Treated Wood.
 
Jeff Creagan
----- Original Message -----
From: John Rose
Sent: Thursday, February 01, 2001 10:03 PM
Subject: Re: Fasteners in Fire Resistant Treated Wood (FRTW)

I would recommend only hot galvanized fasteners for use with FRT wood. There are a few mfrs. of pneumatically driven fasteners that offer hot galvanized nails; however, most typical pneumatically-driven nails are electro-galvanized nails that have thin plating and thus have low resistance to corrosion. FRT wood is treated with chemicals that are corrosive to steel (and zinc) in the presence of moisture in the wood, which can be affected by humidity, condensation or water leaks (as in roof decks). Newer FRT processes are less corrosive to steel.
John Rose/APA Engineered Wood Assn. (retired)

Jeff Creagan wrote:

I'm working on a project where the contractor has submitted a substitution request to use common nails in FRTW; our General Structural Notes require corrosion- resistant fasteners.  The chemical company literature indicates their product is non-corrosive to carbon steel, they back it up with a single research study performed at Mississippi State.  However, the National Evaluation Report indicates that corrosion-resistant fasteners are required (the chemical company maintains this is a boilerplate requirement placed in all FRTW reports but is not appropriate for their product).  The product is D-Blaze, the chemical company is CSI; I'm interested in any experience others have had with this product?  Many thanks in advance. Jeff Creagan, S.E.
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