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, common commercial roofing categories include built-up roof membranes, metal roofing, modified bitumen membranes, single-ply membranes, and spray polyurethane foam roof systems.
Different Commercial Roofing Materials
- Built-up roof membranes
Built-up roofing, commonly known as BUR, has been used in the United States for many decades and is often referred to as “tar and gravel” roofing. A typical built-up roof consists of alternating layers of bitumen and reinforcing fabrics, which are also known as roofing felts or ply sheets. Depending on the system, BUR may be installed over insulation or directly over an appropriate roof deck or substrate. - Metal roofing
There are many metal materials and systems used in commercial roofing, which we have looked at before in our commercial roof systems overview. Examples include galvanized steel, coated steel, aluminum, stainless steel, copper, and other metal roofing products.Metal roofing can be affected by corrosion, movement, failed fasteners, seams, coatings, and other weather-related conditions over time. Depending on the roof and its condition, a compatible acrylic roof coating or other restoration system may be used to help protect and extend the useful life of an existing metal roof.
- Modified bitumen sheet membranes
Modified bitumen roofing is related to built-up roofing but incorporates polymer-modified asphalt materials designed to improve flexibility and performance.Two common categories are SBS-modified and APP-modified bitumen. Their specific properties, reinforcement, surfacing, and installation methods vary by product and roofing system.
- Single-ply roof membranes
Single-ply membranes are factory-manufactured roofing sheets commonly classified into thermoplastic and thermoset materials.Thermoplastic systems include PVC and TPO materials, which are commonly joined using heat-welded seams. Thermoset materials include EPDM, or rubber roofing.
Each system has different characteristics relating to seams, attachment, flexibility, chemical resistance, reflectivity, weathering, repair, and maintenance.
- Spray polyurethane foam roofing
Spray polyurethane foam roofing is created by applying liquid components that react and expand to form a rigid foam layer. A protective coating or other compatible surface is then applied over the foam.The foam layer can provide insulation value, while the protective surface helps shield the SPF from ultraviolet exposure, weather, foot traffic, and other conditions. SPF installation and maintenance require proper equipment, experienced application, and compatible protective coatings.
Roof Restoration and Its Value
Roofing Services
Our professional commercial roof contractors provide:
- Roof maintenance & repair
- Inspections & leak detection
- Energy efficient roof systems
- Complete roof replacement
- Roof life-extending solutions
Over time, commercial roofs can experience weathering, leaks, membrane damage, failed seams, corrosion, drainage problems, or other deterioration.
When the existing roof is structurally sound and otherwise suitable for restoration, a roof restoration may provide a cost-effective alternative to replacement and may help extend the useful life of the existing roof.
Reflective coating systems may also reduce solar heat absorption and potentially lower cooling demand in some buildings, depending on the climate, insulation, HVAC system, building use, and roofing assembly.
Restoration is not appropriate for every roof. Before proceeding, the roof should be evaluated for wet insulation, structural deterioration, serious drainage problems, damaged roofing materials, failed seams or penetrations, trapped moisture, and other conditions that may need to be corrected first.
A commercial roofing contractor can inspect the existing roof and discuss whether repair, restoration, recover, or replacement is appropriate.
