For commercial buildings in Florida, choosing between built-up roofing (BUR) and single-ply membrane roofing requires more than comparing material costs. Florida roofs must withstand intense heat, heavy rain, humidity, wind-driven rain, and hurricane-force winds. The right roofing system depends on the building’s structure, roof design, wind requirements, installation quality, and the specific roof assembly being used.
Both built-up roofing and single-ply membranes can be designed for demanding Florida conditions. However, their construction and hurricane performance differ significantly.
What Is Built-Up Roofing?
Built-up roofing is a multi-layer low-slope roofing system traditionally made with alternating layers of reinforcing fabric and asphalt, topped with a protective surfacing layer. Its multiple layers create redundancy, which can help the system remain watertight when individual areas experience damage.
A major advantage of BUR in hurricane-prone areas is its substantial, multi-layer construction. Properly designed and installed BUR systems can provide strong resistance to wind uplift and weather exposure. FEMA notes that built-up roofing systems have demonstrated good wind performance, although the performance of edge flashing and coping is particularly important because failures at these locations can compromise the roof system.
BUR can also provide excellent protection against punctures and heavy foot traffic, making it suitable for commercial buildings with rooftop equipment and regular maintenance activity.
What Is Single-Ply Membrane Roofing?
Single-ply roofing uses a factory-manufactured membrane installed in a single waterproof layer. Common commercial options include TPO, PVC, and EPDM.
Single-ply systems are popular because they are relatively lightweight, efficient to install, and available in different attachment methods. Fully adhered systems bond the membrane to the substrate, while mechanically attached systems use fasteners and plates to secure the membrane.
For Florida hurricane applications, the attachment method matters considerably. A mechanically attached membrane is not automatically equivalent to a fully adhered membrane when evaluating resistance to extreme wind and debris exposure.
Florida’s building requirements recognize built-up, modified bitumen, fully adhered single-ply, and mechanically attached single-ply systems as roof systems that must demonstrate appropriate performance through recognized testing.
Which Performs Better During a Hurricane?
There is no universal answer that BUR is always better than single-ply roofing.
The complete roof assembly is what matters.
Wind resistance depends on the roof deck, insulation, membrane or BUR layers, fasteners or adhesives, perimeter attachment, flashing, edge metal, parapets, penetrations, and other components working together.
FEMA specifically recommends tested roof systems that meet applicable local wind requirements. It also notes that built-up roofs can perform well in hurricanes when edge flashing and coping are properly designed and secured.
For single-ply roofing, a properly engineered and tested system can also provide excellent hurricane resistance. Fully adhered systems may offer advantages in some high-wind applications, while mechanically attached systems must be selected and installed according to the tested assembly and required wind pressures.
Florida Building Code and Hurricane Requirements
Florida has particularly demanding roofing requirements because of its exposure to hurricanes. The Florida Building Commission maintains product approvals and testing requirements for roofing systems, including systems intended for High-Velocity Hurricane Zone (HVHZ) applications. The current Florida Building Code resources also provide specific product-approval information for roofing assemblies.
This means commercial property owners should not select a roof solely because a membrane or BUR product has a good reputation. The specific assembly should be evaluated for the building’s design pressures and applicable Florida requirements.
BUR vs. Single-Ply: Which Should a Florida Building Choose?
BUR may be a strong choice when a property owner prioritizes multi-layer construction, durability, and resistance to heavy rooftop traffic.
Single-ply may be preferable when the project requires a lightweight system, faster installation, or the flexibility offered by TPO, PVC, or EPDM assemblies.
For hurricane-prone Florida properties, however, installation quality and system engineering can be more important than simply choosing BUR or single-ply. Perimeter and corner zones deserve particular attention because wind pressures can be higher in these areas.
The Bottom Line
Built-up roofing and single-ply membranes can both be effective commercial roofing solutions in Florida. The better choice depends on the building, roof deck, wind design pressures, existing conditions, budget, maintenance requirements, and approved roofing assembly.
For a Florida commercial property, the safest approach is to have a qualified roofing professional evaluate the existing roof and specify a complete system that has been tested and approved for the project’s applicable wind requirements. Shieldline Roofing can help property owners evaluate their existing commercial roof and determine whether BUR, TPO, PVC, or another roofing system is appropriate for Florida’s demanding hurricane environment.
Related Questions
- What is the code-required minimum slope for a built-up roof versus a single-ply membrane in Florida?
- Can a single-ply membrane be installed over a metal building roof?
- Which roof systems perform best above high-heat industrial processes?
- What is the most wind-resistant commercial roofing system for Florida?
- Is PVC roofing better than TPO in Florida’s hurricane zones?
- Does increased fastening in Zones 2 and 3 apply to all roofing materials?
- Which roofing system is better for roofs with many penetrations or complex designs in Florida?
Commercial Roof Replacement / Re-Roofing
