Definitely, a challenging project! Twenty-two separate roof facets compromising 160 squares, with two or more existing layers, of every roof material under the sun, that had to be removed prior to the installation of the new roofing system. Meanwhile, seventeen new air conditioners were being installed in conjunction with eight new windstorm approved curbs, all new rooftop electrical wiring, new siding and paint for the building. The existing roof design included interior drains within the building that were a continual leaking problem, and much of the roof was holding large amounts of water that was playing havoc with roof materials designed to shed water, not hold water.
The new roofing system would involve removing all the existing roof materials down to the decks, many of which required major repairs and replacement, including leveling. All interior drains were being abandoned and a tapered PolyISO insulation system was designed to shed water to all available roof edges. The PolyISO in some areas of the roof exceeded a thickness of ten inches with a ¼” slope per foot, affording a great slope to shed water quickly from the roof. A big bonus to the building was the increased of R-value with the rooftop PolyISO that ranged from R-8 to over R-24 on the various roof facets – more comfortable inside and lower utility costs.
Considering the amount of roof traffic that was likely with servicing the multiple AC units, constant removal of tree leaves and branches, and a multitude other service personnel on the roof, a cover board was installed on the entire roof area. DensDeck® Prime Roof Board, ½” thick, stiffens and stabilizes the roof deck, increases hail impact resistance to the roofing system, provides superior fire protection, improved wind lift performance, and assists in sound isolation.
The waterproofing membrane utilized for the building was a four-ply modified bitumen roofing system manufactured by POLYGLASS®, the leading manufacturer of modified bitumen roofing materials. The Texas based state-of-the-art manufacturing facility in Waco assures availability, value and a premium quality product.
The first layer of material is the Polyglass® Elastobase SBS which is, fastened to the DensDeck and covering the tapered PolyISO, with 3” plates and #12 DP screws – up to 16” long – penetrating through the roof deck. The second layer of material is the Polyglass® Elastoflex SA-V SBS Mid-Ply which utilizes patented ADESO® Dual-Compound Self-Adhesive technology, whereby a “true” polymer modified asphalt compound is applied on the top layer and an aggressive self-adhesive compound is applied on the bottom layer. The third layer of material – another layer of the Polyglass® Elastoflex SA-V – was installed perpendicular to the second layer of material. The fourth and final layer is the Polyglass® Polyflex SA-P Granulated Cap Sheet, a self-adhered APP membrane. Polyflex SA-P membranes are premium, self-adhered plastomeric roofing products, manufactured using patented ADESO® Dual-Compound Self-Adhesive technology, whereby a “true” APP polymer modified asphalt compound is applied on the top layer and an aggressive self-adhesive compound is applied on the bottom layer. Polyflex SA P membranes are built with a high performance reinforced polyester mat to ensure excellent dimensional stability. Polyflex SA-P membranes are finished with granules on the top surface.
The completed 4-Ply system will provide 400-mils of membrane thickness. The four separate plies of material, with staggered and perpendicular seams, will provide a level of redundancy not often seen in a roofing system. In a comparison with a 40-mil single-ply product, there is no comparison. This roofing system is designed and installed to remain in place for “decades to come”, enhanced in the future with applications of silicone elastomeric coatings to extend the life far beyond the typical lifespan of a low-slope roof.
All new Aluminum (.032) drip edge, wall flashings, counter-flashings, pitch-pans and vents were installed in conjunction with the roof replacement. Plumbing vents were flashed with lead. Once the roof was substantially complete, six-inch aluminum gutters and downspouts were installed around the entire perimeter. The gutters will keep the shedding water off the siding, windows and doors and the downspouts will take the water away from the foundation.
The Texas Department of Insurance Product Evaluation – RC-96 – for Polyglass Modified Bitumen Roofing System was implemented in the installation of the new roofing system. Inspections for compliance with the evaluation were completed by the J. Perales Engineering firm.
In addition to the windstorm compliance inspections, the installation was inspected by Polyglass® technical representatives to assure proper installation to comply with warranty requirements. The client is receiving a Polyglass® 20-Year Roofing System Limited Warranty, non-prorated, and no dollar limit (NDL). In addition to coverage for faulty material or defects, the warranty covers ordinary wear & tear, component deficiencies, and workmanship deficiencies. This warranty provides maximum value to the building owner guaranteeing a leak-free roofing system for the next twenty years!