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questions regarding transite roof decking

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Title: questions regarding transite roof decking

        On a current project, a client has requested that I perform an evaluation on an existing roof system for a primary freezer facility. The roof which was constructed in the mid 1960s is comprised of 16" steel joists spaced at 48" o.c. and corrugated asbestos-cement (transite) roof decking. The transite deck has been filled with a lightweight concrete to provide a level surface for the roof insulation. The client wants to put a new roof on the freezer facility; however, they do not want

to remove the transite decking. The roofing contractor plans to strip the roof of its existing components down to the concrete

leveling fill and install the new roof components. The new roof dead load will be approximately 50% of that of the existing.

        With the new roof dead load being decreased, one should feel pretty safe about leaving the transite deck in place; however, I am concerned about the integrity of the transite panels. Based on a site visit, the decking seems to be in good condition with no visible signs of flaking or cracking. Based on a visual examination is it safe to assume that the deck still possesses it strength characteristics.

        For the roof analysis I would like to run some quick deflection numbers on the existing transite deck with the new roof dead load and live loads as required by the current building code. Unfortunately, I know very little about the material properties of transite. What is it's modulus of elasticity.

        I have searched the company library and have not found any information on the transite decking. For comparison purposes, it would like to find some older vendor information on these transite deck panels ( section properties, load tables,

etc.). If anyone has any information on 3/8" thick decking with 3" deep corrugations spaced at 4 1/2" center to center, I would greatly appreciate it. My fax number is 404-370-3646. Any recomendations regarding regulations or other concerns would also be helpful.

Thanks for the Help.
Rob Williams
AGRA Simons Atlanta
Associate Engineer, Structural