Commercial Roof Types: Not All Flat Roofs Are Alike

When it comes to flat or low-slope roofs, there are several varieties of membranes out there. The roof type can be dictated by several factors including budget, building function, local codes, climate, and more. Let’s explore the common commercial roof types used on facilities across the United States. 

Built-Up Roof Systems 

Built-up Roofs often referred to as BUR systems, are one of the oldest flat roof types. They are comprised of multiple layers of protection and have a typical life expectancy of 15 to 30 years. 

Pros of BUR: 

• Extremely durable
• Minimal maintenance required

Cons of BUR:

• Costly to install 
• Can become brittle in cold temperatures 

Modified Bitumen Roof Systems

Modified Bitumen Roofs are a multi-ply system with a typical life expectancy of 15 to 25 years. 

Pros of Modified Bitumen:

• Extremely durable
• Increased flexibility compared to BUR

Cons of Modified Bitumen:

• Costly to install
• Less environmentally friendly than BUR

Single-Ply Roof Systems

There are several types of single-ply roofing, including EPDM, TPO, and PVC. Their life spans range from 10 years to 30 years but are normally not as durable as multi-ply systems. 

Pros of Single-Ply:

• Cost-effective
• Lightweight 

Cons of Single-Ply:

• More prone to punctures, tears, and other damage 
• Increased likelihood of leaks at the seams 

CLP Roof Systems

CLP or Cross Link Polymer Roofing is a new alternative to conventional single-ply systems. The single-ply sheet has additional waterproofing and can also receive a liquid coating over the seams or entire sheet during installation. Life expectancy is between 20 to 30 years. 

Pros of CLP 

• Cost-effective
• Additional waterproofing and strength compared to traditional single-ply
• Ability to be restored which can elongate roof life is best in class when compared to others.

Cons of CLP

• High elasticity of the polymer results in slightly greater dirt pickup
• Additional waterproofing for added protection leads to higher structural load

Spray Polyurethane Foam Roof Systems

Spray Polyurethane Foam or SPF roof systems require specialized equipment and training during installation. The expected life span is 15 to 25 years but will require maintenance and recoating to achieve maximum performance. 

Pros of SPF

• Lightweight
• Seamless for increased waterproofing and insulation

Cons of SPF

• Vulnerable to punctures 
• Little to no protection against the sun’s UV rays