A few drops of water from a leaky roof may be a minor annoyance in most businesses, but when the company makes a high-tech product like circuit boards, it's a major problem.
That is why Mica Corp., 8536 National Blvd., Culver City, is redoing the 103,000 square feet of roofs of its sprawling complex with polyurethane foam roofing (PUF). The job is being done by Sprayfoam Southwest Inc., Tempe, Ariz., a firm that has been successfully applying this roofing product since 1971.
The three buildings in the Mica complex vary in age and are saw-tooth or bow-truss industrial structures dating from the 1930s or earlier, according to waterproofing consultant Marvin L. Harris.
Mica's roofs are covered with roll roofing and are a jumbled landscape of pipes, skylights and air vents. Some of the skylights have been removed--replaced with plywood--and the roofs are being covered with about an inch of sprayed-on polyurethane foam, topped off with ceramic granules to make the roof safer to walk on.
Harris said that most of the objections to PUF installations occurred in early applications and were largely due to inexperience on the part of the workers, improper use of equipment and using the wrong materials.
Sprayfoam Southwest President Keith Coultrap attributes his firm's 96% success rate to the company's experienced workers, quality equipment and materials from suppliers like Dow Corning and General Electric that have sufficient financial capacity to back their warranties.
Depending on code requirements, a polyurethane foam installation involves the removal of old roofing or patching the existing material, priming the surface and applying a one-inch minimum thickness of three-pound density foam with a nominal insulation value of R-7, Harris said.
Because the foam deteriorates rapidly from ultraviolet light if not protected, a coating of acrylic, urethane or silicone is applied on top of the foam, he added.
"Acrylic is the least expensive, urethane is the toughest and silicone is the longest lasting covering," Harris added.
A 1959 USC graduate, he has been associated with Essex Chemical, Parr Inc. and other firms distributing adhesives, sealants and coatings. He is affiliated with the Construction Specification Institute, the Society of Aerospace Materials & Process Engineers and the Associated General Contractors.
The cost of a PUF roof ranges from $1.75 to $2.50 per square foot and comes with a 10-year labor and materials guarantee, Harris said.
"A PUF roof has a projected life in excess of 30 years and is suited to virtually every climate, from desert areas to rainy climates to the Snow Belt," he added. "The insulation is an added bonus, especially in colder climates. The key to a successful installation is the reputation of the contractor and the quality of the materials used."
Traditional tar-based roofing systems account for about 75% of the commercial roofing market, with polyurethane foam installations accounting for about 10%, Harris said.
Although polyurethane foam is generally used for commercial installations, it is suitable for residences, too, Harris said. It is an especially good material to resurface composition or rock roofs, he said.