Complex Roofing Designs

by Jonathan McGaha | February 28, 2017 12:00 am

University fieldhouse roof required multiple redesigns

The Charles H. Sanford Fieldhouse at Colgate University[1] in Hamilton, N.Y., is used by numerous school teams and the general public throughout the year. It has a steel framework overlayed with stone to blend in with other buildings on campus.

Built in the early 1970s, the existing building had many roofing problems, one of which was snow and ice sliding off the slate roof, tearing off several parapet walls from the building. Repairs were made but major leaks persisted and a redesign was in order.

The university selected Bell & Spina Architects-Planners PC[2], Syracuse, N.Y., to develop the plans, and Charles A. Gaetano Construction Corp.[3], Utica, N.Y., as the general contractor. The plan was to remove the remaining slate tiles and re-roof the buiding with a standing seam metal roof system. Gaetano specified 150,000 feet of Perth Amboy, N.J.-based Englert Inc.[4]‘s 18-inch-wide, 22-gauge Galvalume in Dove Gray, and selected Gouverneur, N.Y.-based RSI Sheetmetal and Roofing Inc.[5] to do the metal work.

Work began in June 2015, leaving the general contractor with a tight schedule to complete the job before winter. After scaffolding the entire perimeter, 75,000 feet of slate, flashings and aluminum composite material (ACM) were removed. A temporary membrane was installed over existing Phibro plank decking to facilitate the re-roofing process.

A very detailed and complicated structural steel surface framing system was then installed. It was attached through the existing deck to the existing steel structure. Special drill screws were needed to accomplish this, while locating steel below. This removed most of the roofing stress from the existing deck and transferred it to the existing steel structure.

Early in construction, the added depth of steel on the main roof section and dormers was placing the dormer valleys too close to the ends of the parapet walls. To remedy this, Bell & Spina did a redesign, adding approximately 12 inches of steel over the sub bass steel.

This change raised the finished roof at the dormers and moved the valley centerline out into the main roof, bypassing the parapet wall. Due to previous problems, the scope of work included reinforcing the parapets with heavy steel angles prior to re-roofing. The mason contractor also required Englert to furnish and fabricate 22-gauge stainless steel through-wall flashing, fully soldered, at all parapet walls.

With the steel work going in place, 8-inch batt insulation was installed prior to the standing seam metal roofing panels being set. This work went on simultaneously to ensure the insulation remained dry.

When evaluating the specs, Englert’s specialists informed the general contractor that the architects plans would not earn the 20-year weathertightness warranty they wanted on the standing seam roof. The architects wanted transverse seams with 50- foot panels, which would void weathertightness. Instead, Englert suggested changing the criteria to fabrication of one-piece, 108-foot panels in lieu of the three-piece panels originlly specified.

This took another engineering redesign with changing fixity points, a snow guard redesign with changing load calculations, and expansion and construction of eave detail for eave attachments.

To install the 108-foot panels, it became necessary to manufacture them at the roof edge, 33 feet above grade, sliding them into place one at a time. The roofing contractor worked with their equipment supplier to design a dual-motorized scissor lift platform to house the roll-former and coils. This lift would also be mobile enough to move down the length of the building as needed. Special ramps and jigs were required, as well as many people to guide the panels into place.

The additional time needed required adding more crews to the workforce, and strict coordination of the work of all the various contractors. By working together, getting the job done on time became a posibility. However, the university then added another component, requesting a re-roofing of the four tower roofs.

Englert certified the 20-year weathertightness warranty, and the life expectancy of the Sanford Fieldhouse roof is upwards of 60 years.

As the roof installation progressed, all eyes were on the cooperation and coordination between manufacturer, contractors, masons, electricians, mechanical, plumbers, and the general contractor throughout the project. All originally designed major work was completed by Jan. 21, 2016, and the added components were resumed after the winter snows had melted, and were completed on April 18, 2016.

The complex roofing job earned RSI the Northern New York Builders Exchange Excellence in Construction and Craftsmanship Award for 2016.

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Mitch Gaber is the director of marketing at Englert Inc., Perth Amboy, N.J., and Roger A. LaPierre is the CEO of RSI Sheetmetal and Roofing Inc., Gouverneur, N.Y. To learn more, visit www.englertinc.com[6], and www.rsiroofing.com[7].

Source URL: https://www.metalarchitecture.com/articles/complex-roofing-designs/

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