Thermoplastic Polyolefin (TPO)

Thermoplastic Polyolefin (TPO)

Thermoplastic polyolefin (TPO) is a white, single-ply roofing membrane. TPO has been around since the 1990’s and is most commonly used on low-slope flat roofs. According to the National Roofing Contractors Association (NRCA), roughly 40% of all commercial roofing work performed today involves the use of TPO. There are many advantages of TPO roofing, including:

• Reflective Properties: The white membrane reflects sunlight, which can save on energy bills in the summer.
• Durability: TPO is a durable material resistant to mold, dirt accumulation, tears, and punctures. It is also UV, ozone, and chemical resistant.
• Cost Effectiveness: TPO is very affordable compared to many other commercial roofing materials. While it should be installed by professionals, it is relatively easy to install.
• Environmentally Friendly: Due to the energy saving properties and the fact that TPO can be 100% recycled, TPO is considered an environmentally friendly roofing option.

Magnesium Hydroxide is used in TPO roofing as a flame retardant. By weight, magnesium hydroxide is about 31% water. When exposed to high temperatures, this water vapor is released. This cools the membrane, and helps slow the spread of a fire. By incorporating magnesium hydroxide, manufacturers can meet stringent fire safety standards without sacrificing the physical properties of the roofing system, such as durability, flexibility, and energy efficiency.

Martin Marietta Magnesia Specialties manufactures MagShield^®S NB 10, a chemically precipitated grade of coated magnesium hydroxide made from magnesium-rich brine and dolomitic lime. At >98.5% purity, MagShield^®S NB 10 is a non-halogenated flame retardant used in many applications such as TPO roofing, EPDM, and some wire and cable applications.