Today, we cover the different generic types of commercial roofing materials that are available for flat roofs and low slope commercial roofs.
According to the National Roofing Contractors Association, there are five common commercial roofing materials. These include: built-up roof membranes, metal paneling, modified bitumen sheet membranes, single-ply membranes, and spray polyurethane foam roof systems.
Different Commercial Roofing Materials
- Built-up roof membranes
According to the NRCA, these roofing materials have been used in the United States for over a century. The public more commonly knows them as “tar and gravel” roofs. A finished product of this membrane typically has a makeup of alternating levels of bitumen and reinforcing fabrics. These “reinforcement” fabrics are also referred to as “roofing felts” or “ply sheets”. If a BUR system is mechanically fastened, it may feature a foundational ply sheet. BUR membranes are often applied directly to insulation or the roof deck. The bitumen used is often asphalt, coal tar, or a cold-applied adhesive.
- Metal paneling
When it comes to low slope roofs, the NRCA lists one thing being available for application: structural metal paneling. There are many metal materials which can be used for roofing, which we have taken a look at before in our commercial roof systems overview: corrugated galvanized steel, aggregates of zinc, aluminum, and silicon-coated steel, metal tile sheets, stainless steel, copper, aluminum, stone-coated steel, lead, and tin. Because metal paneling may be compromised by harsh weather conditions or from long sun exposure, certain kinds of metal roof materials, especially steel, are often “treated” with defect-inhibiting surfacing layers. It is not unusual for a metal roof system to be treated with a surface layer acrylic roof coating for long-term durability and protection value.
- Modified bitumen sheet membranes
These membranes are similar to built-up roofing, but feature additional tensile strength and durability with rubber-based polymers incorporated into the material. They are installed in multiple layers for reinforcement. Generally speaking, there are two types of modified bitumen roofing membranes; SBS polymer-modified bitumen membranes and APP polymer-modified bitumen membranes. The APPs typically leave behind a plastic-like quality to asphalt, and SBSs leave behind a rubber-like quality.
- Single-ply roof membranes
These membranes are factory-made and classified into two groups: thermoplastic materials (which include PVC and TPO materials) and thermoset materials (which includes EPDM or rubber roofing). The thermoplastic materials stand apart from thermoset materials in that they do not have chemical crosslinking. There are five subcategories of thermoplastics, but the most common are PVC and TPO materials. Alternatively, thermoset materials have polymers that have chemical crosslinks, or have been “vulcanized”. The most common thermoset membrane is EPDM material, which is derived from ethylene and propylene.
- Spray polyurethane foam roofing
This material is foam-based and features a two-part mixture which is applied as the system’s base layer. Thereafter, a surfacing layer is applied on top, which can be membranous but is often roof coating-based. The base layer of spray polyurethane foam insulation is applied at different levels of thickness for greater insulation value, or R-value. The surfacing layer serves as the protection against damaging agents such as harmful ultraviolet rays or powerful storms.
Roof Restoration and Its Value
Our professional commercial roof contractors provide:
- Roof maintenance & repair
- Inspections & leak detection
- Energy efficient roof systems
- Complete roof replacement
- Roof life-extending solutions
A roof restoration can reinforce an existing commercial roof’s life, bring the roof back to its prior performance ability, and even give building owners strong energy benefits, among other things.
Do you want energy-saving roofing solutions from roofing professionals whom you can trust? Call us today at 800-670-5583 for more information.