At Central Roofing, we are asked constantly why commercial buildings have flat tops. The primary reason why is so the HVAC and ventilation units rest on top of the building away from foot traffic. You’ll see a flat roof on nearly every commercial building in Los Angeles, but they aren’t all the same.
You Have Options
All commercial roofing systems must create an impenetrable barrier between a building exterior and interior to prevent water damage. Six common systems used on commercial buildings include
• BUR or Built-Up Roof
• Modified Bitumen
• PVC or Polyvinyl Chloride
• TPO or Thermoplastic Polyolefin
Many factors determine which roofing material system is best for you. Some are
• Energy efficiency
There’s no reason to be confused about which option works best. Let’s break this down further.
Built-Up or BUR System
A BUR system scores high in aesthetics because of its gravel top layer. It’s also durable and stands up to heavy foot traffic. Multiple layers make it energy efficient. It is inexpensive overall, but your roof might need additional reinforcement. Expect 15 to 20 years out of a BUR system.
Modified bitumen is also a multi-layered system. A base layer is attached to your roof deck, and overlaps are applied with a durable permanent adhesive. A granule top boosts the final product’s aesthetic and reflects the sunlight well. Expect 10 to 20 years’ longevity.
PVC or Polyvinyl Chloride
You’ll pay more for PVC, but it’s worth it. This single-layer option uses PVC membrane to resist water and sunlight. The material is rolled out in sheets so there are seams, but once sealed they’re stronger than the sheets. A PVC system can last up to 30 years.
If you prefer a seamless system, silicone may be the way to go. Silicone coating is sprayed on your existing roof and cured. The seal is nearly impenetrable and energy efficient, which makes it a little pricier. Silicone lasts up to 20 years.
TPO or Thermoplastic Polyolefin
TPO combines ethylene, propylene, rubber and other fillers to give your building a durable and “green” roof system. We’re experienced in using this material, which has only been around since the 1990s. You can expect your TPO roof to last seven to 20 years.
This is a lot of information to take in, so give us a call at 310-527-6770. We’d love to send someone out to your property to discuss each flat roof option with you and provide a free estimate.