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Overview of the roof:

Starting with 4 x 6 aluminum I-beams welded 4 x 4 aluminum to the I-beam to form the framework of the roof system. Each aluminum 4 x 4 has a welded foot (plate)  aprox. 6 in x 10 in . Each foot has 6 drilled holes to accommodate six ITW Redhead expansion bolts. On top of the frame we installed a commercial product knows as Tectum III. Tectum III is a combination structure and insulation product.  It is sandwiched with 3/4" OSB on the top and a fiberglass looking material at the bottom. Tectum III has a tongue and groove application. The Tectum III we selected is 8" thick. When it is laid on top of the AL and tapped into place, a 10" self-tapping sheetmetal screw with a washer is drilled thru the Tectum and into the AL frame. You have to have a certain number per inch for the warranty to be good. Tectum III is very strong structurally because of the 3/4" plywood on one side and the reinforced fiberglass on the other side. It also possesses an R-value of 43 for insulation properties.

On top of the Tectum III is a layer of tongue and groove 3/4" plywood. On top of the plywood is a layer of a product called SharkSkin Roofing Underlay which is the real waterproofing agent for the roof. To install it, you peel the backing off of it and lay it horizontal layers on top of the plywood. If a nail is driven thru this product it will form a seal around the nail maintaining the waterproof integrity of the roof. For an extra measure of strength wind resistance and to insure 100% waterproofing we installed a second layer of 3/4" tongue and groove plywood turned perpendicular to the first layer with another layer of Sharkskin on top of it.