Commercial Roofing Systems
So you want to build a roof, what system will you use? Single ply or built-up or modified. The built-up types of roof systems include about 20 manufacturers and a hundred or so products. Without listing any particular manufacturer, I will attempt to cover most of the major roofing systems and the possitive/negative aspects of each system.
The first thing that you need to know when it comes to roof systems is that you will never know everything. Even the roofing professional who has dedicated his entire career to roofing doesn’t know everything. It is important to know enough about roof systems to have a general sense of what type of system may work best for your building. No roof system is right for every building.
Major Types of Commercial Roof Systems
Asphaltic Roof Systems
A modified roof system is one in which the asphalt has been modified by an additive. The modified asphalt is then factory applied to the roof membrane. The two types of modifieds are APP (Atactic Polypropylene) and SBS (Styrene Butadiene Styrene.) Modifieds can be used either with or without insulation.
B. Hot mop (standard built-up roof system)
A standard built up roof system is one in which a porous ply sheet is laid into hot asphalt. As the asphalt cools it forms a watertight seal. The membrane is not the waterproofing agent, its sole purpose is to stabilize the asphalt. The benefit of the built-up roof system is redundancy – three or four layers of smooth continuous unbroken films of asphalt which is the waterproofing agent.
C. Options for the roof surface
Single Ply Roof Systems
A single ply roof system is one in which a single layer of either rubberized or plasticized membrane is installed to create a watertight roof system. There are primarily three types of single ply roof systems: 1.) EPDM (Ethylene Propylene Diene Monomer) is a rubberized membrane with taped seams, 2.) TPO (Thermoplastic Polyolefin) is a plasticized membrane with welded seams, 3.) PVC (Polyvinyl Chloride) is a plasticized membrane with welded seams.