Roof Coatings Phoenix Installing Mechanically Attached Commercial Roofing Systems

Mechanically attached system is your best choice when speed and ease of installation are important. It features metal plates fastened in the seam overlap spaced according to the roof’s wind uplift requirements, fully adhered using some type of adhesive. Mechanically attached systems are best used when weight is a consideration, when the system is to be installed during cooler weather or when a roof is being re-covered. Structural concrete decks are not a good choice for mechanically attached systems states Roof Coatings Phoenix. Installing fasteners into the concrete can create problems in the future as the roof ages and allows water to penetrate to the deck. The fasteners can rust, spalling the concrete. The oil crisis of the 1970s clearly showed the need for alternatives to petroleum-based roofing. To answer this need, a plethora of lightweight flexible roofing membranes came on the market. They were easy and inexpensive to install to add to the mix; new methods of installation have been developed.

Roof Coatings Phoenix Installing Mechanically Attached Commercial Roofing Systems

Coverboard

Most roofing systems need insulation or a coverboard to improve insulating value of the roof system, improve the fire resistance, and to provide a smooth surface for the membranes insulation. Types of insulation that may be used are polyisocyanurate, polystyrene insulation, extruded polystyrene in 15 psi and expanded polystyrene in 15 psi, perlite, high density uncoated wood, fiber board, and fibrous glass. Do not use scraps of insulation or coverboard smaller than 2″ x 2″. Minimizing the number of joints will improve the performance of the insulation. Stagger multiple layers of the insulation at least 6″ so the joints do not align. Roof Coatings Phoenix expresses that this will also reduce energy loss at the joints. Support the edges properly assuring that they are properly supported to reduce potential damage to the insulation. Replace wet, warped, buckled, or damaged insulation or coverboard.

Thermoplastic Membranes

Roof Coatings Phoenix recognizes two major thermoplastic membranes currently on the market. Thermoplastic mechanically attached systems lend themselves to cool-weather installation as there are few solvents and no hot asphalt to be concerned with. However, as in all cases of thermoplastic membranes, the temperature of the heat welding of the seams is critical to getting a good bond and cool weather must be taken into consideration when welding. Mechanically attached EPDM is a good candidate for cool-weather installation if tape is used as the seam adhesive. Contact-adhesive seams can be used if the adhesive is kept warm until just before it is applied and the longer set-up time for the contact adhesive is taken into consideration.

Steel

Steel is an excellent choice for mechanically attached systems, especially when installing a new roofing system over a structural standing seam metal building, because the mechanical attachment is light weight and less likely to overload the highly engineered weight limits of the building. Wood and cementitious wood fiber are also very good decks for mechanically fastened systems. We at Roof Coatings Phoenix voice that mechanically attached membranes are generally not the preferred way of installing single plies over structural concrete decks but are good for use on steel or wood. A fully adhered or ballasted system is more appropriate for structural concrete to avoid damage to the concrete.

Roof Coatings Phoenix Installing Mechanically Attached Commercial Roofing Systems