Commercial Flat Roof Options

Which is the Best Material for Your Commercial Flat Roof?

Most industrial, commercial and multi-unit housing buildings have flat roofs, meaning that they have very little slope and often house equipment such as HVAC and satellite systems. If you are in the process of constructing a new commercial building or considering repairing or replacing your flat roof system, it makes sense to understand your flat roofing options.

There are different types of roofing systems for commercial flat roofs, both in the single-ply and built-up roof categories, each with their own pros and cons. Single-Ply simply means that a single layer of membrane is either fully adhered or mechanically attached. You should be aware that not all single-ply membranes are created equal -TPO, PVC and KEE all have very different formulations, durability, specs and cost. Built-Up Roofs are installed using hot or cold asphalt sandwiched between several layers of rolled fiberglass or polyester membrane with a granulated, gravel or smooth coated surface.

Flat Roof Option #1 – KEE Based Single Ply Roofing

KEEY-membrane_260x211KEE, or Ketone Ethylene Ester is manufactured by FiberTite and is the premium single ply product on the market today. This is a modified PVC single ply roofing membrane that incorporates a unique plasticizer that keeps the material indefinitely flexible, while also making it highly resistant to environmental extremes and exposure to a wide range of chemicals and pollutants. Building owners who want their roofing to last as long as possible, or who need extra resistance to weather and chemical attack, can specify roofing made with DuPont™ Elvaloy® KEE terpolymer to assure decades of problem-free service.

Pros:These ultra-strong roofs can last over 30 years. Seams welded with hot air form a weather tight seal. Stays flexible and “workable” indefinitely. White reflective surface help reduce energy costs.

Cons: Costs are somewhat higher than PVC or TPO.

Flat Roof System #2 – PVC Single Ply Roofing

high_quality_PVC_roofing_membranePVC or Poly Vinyl Chloride is vinyl based single ply roofing membrane that can be fully adhered or mechanically attached. PVC is considered the mid-range single ply product available today.

Pros: Proven performance in the toughest conditions with the strength to prevent tearing and punctures, low water absorption, resistance to UV exposure and because of their strength and different types of installation procedures, PVC roofs have great wind uplift resistance. Chemicals are not uncommon on top of manufacturing facilities and restaurants. PVC roofs are very resistant to chemical damage. Animal fat from grease vents on restaurants can damage an asphalt-based roof and some other single-ply roofs, but it won’t hurt a PVC roof. Their white reflective surface meets California’s Title 24 requirements.

Cons: PVC single ply roofs are somewhat higher in cost than TPO single ply.

Flat Roof Option #3: TPO Single Ply Roofing

TPO_Roof_MembraneTPO, Thermo Plastic Olefin, is a vinyl based, single ply roofing membrane that is one of the least expensive single ply roofing system.

Pros: TPO membranes are in the moderate cost range and are pretty much a maintenance free roofing system.

Cons: Longevity of TPO roofs vary greatly depending on membrane’s thickness. TPO roofs are slightly higher in cost than Built-up roofs.

Flat Roof Option #4: Built-Up Roof (BUR) Hot Asphalt Fiberglass

BUR Black RoofBuilt-up Roofs, also known as BUR, are built with three or more plies of reinforcing membrane alternated with hot tar then covered with a layer of gravel, granule surfacing or a smooth coating. Once made of tarpaper, more-advanced materials such as polyester and fiberglass-reinforced membranes are most often employed today.  These strong membranes are laminated together with hot asphalt and surfaced with various coatings or aggregates.

Pros:BUR roofs are popular since they have proven performance and can be less expensive than the other roofing materials. BUR Roof Systems are well insulated because of the many layers and a gravel surface is a good fire retardant. A gravel surface is attractive, which is important if there are windows overlooking the roof.

Cons:The materials used for BUR roofs, such as gravel, are extremely heavy and often require reinforcing the roof structure prior to installation. The time and materials to reinforce the roof structure can add up to additional expense. The gravel can make it hard to locate the source of leaks and can clog gutters and scuppers.

Flat Roof Option #5: Built-Up Polara® Polyester Membrane Roofing System

PolaraThe Polara® Polyester Reinforced Built-up Roofing System is similar to the asphalt fiberglass roofing system but polyester is much stronger than fiberglass so fewer layers are needed.

Pros:The Polara® Polyester Reinforced Membrane is extremely strong and requires little maintenance. Because of the increased strength, fewer layers are needed resulting in less weight on the structure. This system can be installed over high-stress roof structures that cause normal roofing systems to split and tear.

Cons: Costs are slightly higher than Fiberglass BUR roofs but can be well worth it with longer roof life.

Looking to Replace Your Commercial Roof?

Look to a professional commercial roofing contractor to help you determine the best roofing system for your needs. Sully-Jones is San Diego’s Flat Roof Expert. We will provide a free inspection and our experienced personnel are knowledgeable on all different roofing systems, not just our own, so they can answer most questions regardless of the system you’re interested in.  Get a Free Inspection & Quote Today!

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