The versatility of McElroy Metal's 238T symmetrical standing seam roof profile is unquestionable, as is the cleverness of the company's innovative approach to handling rooftop skylights when its panel systems are utilized in metal-over-metal retrofit roof applications. Both the panel system and the approach are on display at a recently completed roof-over at Northwest Distributors in Hays, KS.  

Northwest Distributors is a busy warehouse facility dealing with auto parts and supplies. The R-panel metal roofing on the original building and an addition both sustained damage in several hailstorms over the years. After a 2017 hailstorm, the insurance company for Northwest Distributors agreed a new roof was needed and it would cover the cost.

The tried and true method of roof replacement involves complete roofing tear-off and replacement. Obviously, this would expose the valuable contents of the facility to the elements. Roofmasters Roofing & Sheet Metal, also of Hays, proposed an alternate approach utilizing the patented 238T tall clip re-cover using the 238T symmetrical standing seam roofing system from McElroy Metal.

The roof re-cover would not require the removal of any existing roofing panels and therefore, would not interrupt any activity inside. It would be business-as-usual at Northwest Distributors during the install.

The owners at Northwest Distributors decided to go with the re-cover. Project manager Andrew Bizzell and project superintendent Andy Littrel headed up the assignment for Roofmasters.

“The tall clip re-cover cost is about the same as a removal, but the benefit comes from the contents of the building not being exposed to potential damage from rain or wind or hail,” says Bizzell. “Plus, they were able to keep working without interruption. That saved Northwest money as well.”

Panels for the 58,000-sqaure-foot re-cover were produced onsite and stacked on the roof. Roofmasters owns its own roll former that produces the 238T symmetrical standing seam panel. The 24-gauge panels are 24 inches wide with striations in PVDF Regal White. Panels were approximately 64 feet long.

“It really was a straightforward job,” Bizzell says. “We have installed several re-covers with the 238T. We like the ease of installation. It provides a great benefit to the building owner because if a panel is damaged, a single panel can be removed and replaced anywhere on the roof. If a panel is damaged with another type of standing seam system, you have to start on an end and remove all of the panels up to and including the damaged panel. Obviously, that is a much greater expense.”

Bizzell says not all insurance policies cover cosmetic damage sustained in weather events like hailstorms. The symmetrical standing seam system allows for the replacement of a single panel or only damaged panels the owner feels the need to replace, reducing his financial hit.

Roofmasters installed 3-1/2 inches of batt insulation between the original roof and the new panels to eliminate the possibility of condensation forming between the two metal systems. It also provided the owner with an added R-value of R-12, which will help reduce heating and cooling costs.

It should be noted the Northwest Distributors warehouse roof includes 36 skylights, a feature the owner wanted to keep. To eliminate the problem of standing water behind curbs above the skylights, Roofmasters installed transverse panels from the top of the skylight to the ridge. Transverse panels are installed perpendicular to the slope using floating purlins that lift the transverse panels and skylights above the field of the new roof. This system lifts the leak-prone skylights out of the water plane. None of the exposed fasteners used for this detail penetrate the roof.

Beneath the center of the transverse panels, a center support was installed. In addition to support, it adds a little pitch to the transverse panels to aid water flow.

Roofmasters installed a polycarbonate skylight panel from MWI Components over the original skylight hole.

“We use transverse panels with skylights and other roof penetrations,” Bizzell says. “We also use the traditional curb. Installed correctly, they both do what they’re supposed to do.