Esperanto is an artificial language invented in 1887 so any two people in the world could talk. You can find it online with apps like DuoLingo and Lernu! Being able to speak the same language means sharing ideas. When your roofer talks about PVC or TPO, you may be lost at exactly the moment you need to understand your commercial roofer. Here is an overview of three commercial roof covering types. 


Single-ply membrane roofing is a thin, synthetic material often attached to a reinforcing scrim, or net. The material can be one of several plastics, either thermoset membranes or thermoplastics. 

  • Thermoset membrane — Ethylene propylene diene monomer (EPDM) and, in older roofs, Hypalon brand chlorosulfonated polyethylene synthetic rubber; these remain solids and can withstand high heat.
  • Thermoplastics — Thermoplastic polyolefin (TPO) and polyvinyl chloride (PVC); these melt in high heat and can be reshaped.

Single-ply membranes can be manufactured in very wide rolls, minimizing seams. They can be factory-made to precisely fit a roof, they install quickly, and they wear very well. 

Built-Up Roofing (BUR)

Tried, tested, and true to its purpose, Built-Up Roofing (BUR) is asphalt roofing which has had a presence in industry, commercial buildings, and low-slope roofs for more than 100 years. It is economical, predictable to install, and flexible enough to fit just about any roof. 

Roofing felts with synthetic or natural strengtheners embedded in them are rolled out over base sheets attached to the roof deck. These felts are glued down onto the base sheet with asphalt, hot tar, or an adhesive. Ballast or cap sheets are layered over the felt and then a final layer of asphalt is applied.

BUR is old-school, time-tested, and very budget-friendly.

Modified Bitumen or Mod-Bit

Bitumen is biblically old. It oozes naturally from the ground but is manufactured under its more familiar name, asphalt. Modified-Bitumen roofing, Mod-Bit, or MB roofing systems are installed as 39”-wide rolled materials with sealed seams.

Mod-Bit, though layered, is usually considered a single-ply system. Self-adhered rolls are common and make installation fast, odor-free, and long-lasting. Mod-Bit roofs generally do not last as long as thermoset or thermoplastic roofs, but are also normally less expensive.

Still confused? Please feel free to contact us today at VanWeelden Company at our Des Moines, Iowa headquarters. We would be glad to sit down with you, explain the various commercial roofing products, and assess your company building’s roof.