In 1999, JG Smith Construction commenced maintenance and service repairs on metal roof systems at the Mills Pride complex in southern Ohio. Professional roof inspections were executed to ascertain the current condition of the system components. The inspections and evaluations were summarized in report format and submitted to the facilities manager for review. The report categorized roof system conditions as either 1) currently maintainable, 2) repairs needed to achieve a level of maintainability, and 3) recommended replacement due to oxidation and severe deterioration. Several buildings fell into category 3, and recommendations for near term replacement was proposed.
[Mills Pride is a major manufacturer of “ready to assembly” (RTA) furniture and finished cabinetry. During the 1980’s and 1990’s the company experienced significant growth that precipitated an aggressive building program to accommodate the expansion. Over a fifteen-year period, more than a dozen pre-engineered metal buildings, totaling more than 4,000,000 sq. ft. were erected to house all phases of lumber preparation through finished product packaging. An interesting note about the buildings is that each has been named after an American president. (i.e. Truman, Roosevelt, Jackson, Kennedy, etc.)]
The early metal buildings were assembled with conventional, 12” o/c “R” panels. These “through fastened” metal roof systems were installed over EPS thermal blocks and vinyl faced fiberglass insulation. Most of the manufacturing facilities at the complex exceed 100,000 sq. ft. in footprint. These large roofs were installed without vertical or horizontal expansion joints, and endured thermal cycle transients exceeding 200 degrees F each year.
As is with growth and most building expansion programs, maintenance is often a last thought, and with roof systems it is the old adage of “out of sight out of mind”. For fifteen years repetitive, roof panel expansion and contraction slowly caused purlin fasteners to lose preload and disengagement from the panel surface.
Subsequent water infiltration under the EPDM washers and down the thread path established a modest collection of moisture in the insulation, between the vapor barrier and the metal panels. Because the moisture could not escape, it continuously cycled through the evaporation – condensation phases. The result was severe under panel oxidation. Many panels were completely rusted through at fastener heads and at panel flutes in the field.
The deterioration created a safety issue both for personnel and structurally. Conventional “R” panel roofs depend on proper purlin fastening to maintain a “diaphragm effect”. The “through fastened” roof panels provide rigid bridging between the purlins to minimize buckling and failure. These characteristics were being compromised.
Installation of new, galvalume plus, standing seam metal roof systems, was recommended for two buildings. Mills Pride management agreed and provided JG Smith Construction authorization to begin work on the Lincoln building. The 175,000 sq. ft. Lincoln building received a “STAR” standing seam metal retro-fit roof in 2003. Prior to the project an evaluation of the building structure indicated that it could support the additional 1.8 lbs. per sq. ft. for the proposed roof retro-fit without a tear-off.
The new standing seam metal roof panels on the Lincoln building were supported by 3” tall, stand-off clips. However, variations in modularity during the original “R” panel assembly, and likewise during the standing seam panel installation created unforeseen problems. Many of the panel clips were often positioned over existing “R” panel ribs. This created the demand for a bridging component. On this particular project approximately 5,000 heavy gauge hat sections were cut to accommodate the interfere issue. This unscheduled work added about one month to the job, and thousands of extra dollars in material and labor costs.
In the spring of 2004, Mills Pride awarded a second roof retro-fit project to JG Smith Construction for the Washington building. This 110,000 sq. ft. facility had many of the same rusting and deterioration problems as the Lincoln building.
In order to eliminate the same expensive mistake incurred during the Lincoln building roof retro-fit project, we turned to “Red” and his “Roof Hugger” support system. This light weight, heavy gauge framing system is quickly, and efficiently installed over the existing purlin structure. Not only did the “Roof Hugger” system eliminate high rib interference, but it also provided for the re-establishment of panel to purlin clamp loading, and the subsequent enhancement of structural integrity.
The Washington building installation went off without a hitch, and was completed in eight weeks. We had a great grew on the project, and they loved the “Hugger” system. The “Roof Hugger” retro-fit component is worth its weight in gold. We will never again complete another metal roof retro-fit project without “Roof Huggers”. Special thanks to “Red” at Roof Hugger for making our life a whole lot easier.
GREAT RETRO-FIT "RE-ROOF" ARTICLE BY THE J.G. SMITH CO.
Of greatest importance to all in our industry is to have developed the confidence of the client in the integrity and work ethics of this contractor so that ongoing business is a pleasure for both parties. Such provides a respected pool of references to secure many more construction and maintenance jobs for J. G. SMITH.
By D. V. MC CONNOHIE