Low slope(flat) roofing includes water impermeable, or weatherproof, types of roof membranes installed on slopes less than or equal to 3:12 (14 degrees). There is no one roof system that is best for all applications. Keep in mind that even if you are using the best materials, your roof system still can be installed improperly and you could end up with a leaky roof. Good workmanship and proper attention to detail (e.g., flashing and drainage issues) are just as important as material selection. Also, maintenance plays an important role in roof system integrity and service life.

At Tekline Roofing we specialize in the installation of Thermoplastic membranes (e.g., PVC, TPO) The most common thermoplastic roof membranes are PVC and TPO. The following provides general descriptions of these two systems.


  • Thermoplastic Olefin (TPO)
    TPO membranes are produced by calendering with lamination, extrusion with lamination, or extrusion-coating techniques. TPO sheets are a blend of polypropylene and ethylene propylene polymers and usually are reinforced with polyester. TPO sheets contain colorant, flame retardants, UV absorbers and other proprietary substances to achieve desired physical properties. Sheet widths range from 6 feet to 12 feet wide. Sheets are typically 40 mils to 100 mils thick. Seams are sealed by heat welded with hot air. TPO membranes commonly are white.
    PVC and TPO roof membranes can be installed fully adhered, mechanically attached or ballasted. Most PVC and TPO membranes do not receive surfacings.
  • Polyvinyl Chloride (PVC)
    PVC sheets are produced by calendaring, spread coating or extruding, and typically are reinforced with polyester or glass-fiber mats or scrim. PVC sheets contain plasticizers and stabilizers, as well as other additives to impart flexibility and achieve other desired physical properties. Some membranes are available with nonwoven fleece backing adhered to the underside of a sheet. Sheet widths range from 6 feet to 12 feet wide. Sheets are typically 45 mils to 90 mils thick. Seams are sealed by heat or chemical welding. PVC membranes are produced in numerous colors, though gray and white are the most common.