Historic Perspective

Known throughout the globe for their stereophones, Koss Corporation has invested in their Milwaukee world headquarters facility through a major reroofing program.

To those familiar with the northeast side of Milwaukee, this facility is located right alongside the hard-to-miss Koss billboard that has displayed Koss’ uncanny ability to find creative slogans for their Koss Stereophones.

Like many major Christiansen projects, this effort began with an evaluation of current roof conditions and a detailed review of Koss Corporation’s needs for energy efficiency and long-term roof system performance.

A 1986 modified bitumen roof membrane “recover” was in place over an old smooth surfaced built-up membrane and minimal insulation on both structurally sloped metal and wood decking. The entire roof area (123,000 square feet) was designed to drain to a few roof drains, an outside perimeter edge, and undersized drain scupper boxes. The actual drain valley areas were not properly sloped creating ponding water and membrane deterioration. Roof leaks were a recurring problem that led to some structural deck deterioration. Another challenge was the numerous structural steel I-beam deck supports, dozens of rooftop units to be disconnected, and hundreds of feet of gas lines and large electrical conduit.

Our recommendations for the project included a complete removal of the existing system. To meet Koss’ need for energy efficiency, we installed a base layer of 2.5” Polyisocyanurate insulation mechanically attached and a ¾” perlite cover board set in hot asphalt with staggered joints. To increase the flow of water off the roof, we incorporated ¼” per foot tapered drainage saddles 10’ wide along the entire 1,460 lineal feet of drain valleys and parapet wall areas. Further, we provided oversized and custom fabricated 24 gauge drain scupper boxes with conductor pipes that were installed at the low profile perimeters. These elements solved their internal thermal requirements and drainage problems.

The need for long-term performance was addressed through a recommended four-ply built-up roof membrane consisting of Type IV fiberglass felts. All of the perimeters, unit curbs, parapet walls and individual I-beam penetrations (count them - 85 in all!) were flashed and sealed with a high performance SBS granular surfaced modified bitumen membrane. A further performance issue had to do with the prospect of sea gulls nesting on gravel surfaced roof systems. To address this, the finished 4-ply roof membrane was glaze coated with Type III hot asphalt and then coated with an asphalt based, asbestos-free aluminum roof coating at the rate of 2 gallons per 100 sq. ft. of roof area. We have found this alternative coating to be much less attractive to sea gulls.

To help ensure proper long term performance, Koss requested that we provide a comprehensive roof maintenance program. This proactive approach by Koss Corporation will ensure that the new roof system performs as designed for years and years to come.

By completion of the project we will have filled 65, 30-yard containers of existing roofing materials, mechanically fastened 3,844 sheets of 4’ x 8’ Iso utilizing some 6,150 fasteners, and mopped in 7,688 sheets of 4’ x 4’ ¾” perlite insulation and 990 rolls of Type IV glass felts utilizing 77 tons of asphalt! All of this covered in 2,460 gallons of aluminum roof coating and protected for the long term through on-going maintenance to keep Koss in the dry as a world leader in state-of-the-art stereophone production.