McElroy PBR-Panel 2008 roof profile

The McElroy PBR-Panel roof profile of 2007 and 2008 is an exposed-fastener steel roof cross-section drawn by McElroy Metal as drawing E5, prepared June 11, 2007. The same section appears in Miami-Dade notice of acceptance 08-1007.06, approved December 4, 2008, for a 24-gauge steel roof panel. The notice expired December 4, 2013.

PBR and R-panel are broad names for exposed-fastener sheets. The exact folds and side laps of this panel come from the dated drawing.

Drawing E5 shows three 12-inch modules across a 36-inch covered width. The cover carries a tolerance of plus or minus 1/16 inch. The minor modules repeat on 4-inch centers.

• Cover: 36 inches, plus or minus 1/16 inch
• Major rib centers: 12 inches
• Minor module: 4 inches
• Major rib rise: 1 1/4 inches, typical
• Major crest flat: 1 inch, typical
• Minor raised rib: 1/4 inch, typical
• Minor top flat: 3/4 inch, typical
• Small recess: 3/16 inch, typical
• End offset: 0.21 inch, plus or minus 0.12 inch

The main web is marked 50 degrees typical. The outboard web is marked 55 degrees, and a minor-rib web is marked 30 degrees. Other chain dimensions printed around the detailed rib are 1.53, 0.69, 1.38, 1.42 and 3.07 inches.

The one-page profile sheet carries the key callouts, and the original E5 drawing holds the placement of each chain dimension and the drawn side-edge details. The 36-inch figure is the installed cover, not the width of the flat coil before forming.

The 2008 approval drawing names 24-gauge steel with a stated minimum thickness of 0.023 inch, minimum yield strength of 50 ksi and tensile strength of 65 ksi. The material row identifies ASTM A792 steel with an AZ 55 coating for bare material and AZ 50 for painted material. Kynar 500 is named as the paint coating in the approved assembly.

McElroy Technical Bulletin 07-244-06, issued June 1, 2006, names PBR-Panel and shows a table for 26-gauge material. The panel weight is 0.90 psf and the yield strength is 50 ksi. The bulletin depicts the same 36-inch cover, 12-inch major spacing and 1 1/4-inch rib rise as the E5 drawing.

The bulletin tabulates allowable uniform loads in pounds per square foot for single, two-span, three-span and four-span conditions at spans listed in feet. Load types are positive wind, negative wind, live load, and deflection at L/180 and L/240. Section properties are given for the bottom and the top of the panel in compression, with Ix, Se, Ma, Va and Pa values for one foot of panel width.

• Section properties are calculated under the 2001 AISI North American Specification for the Design of Cold-Formed Steel Structural Members.
• Allowable loads assume equal span lengths.
• Positive wind and negative wind values are not increased by 33 1/3 percent.
• Panel weight is not deducted from the allowable loads.
• Positive wind and live load values are limited by web crippling using a bearing length of 2 inches.

The bulletin covers 26-gauge material, while the E5 approval drawing covers 24-gauge material. The two documents carry separate grade and load values.

McElroy markets an R-Panel family with a 36-inch cover and 12-inch rib spacing. The dated E5 section is a separate drawn profile within the broader group of exposed-fastener PBR and R-panel roof sheets.