What You Need To Know About Commercial Roof Life Expectancy

What You Need To Know About Commercial Roof Life Expectancy

Your business is thriving and you recently expanded by acquiring an existing building. Congratulations on inheriting a new-to-you roof on your commercial property! Now you are faced with the same dilemma every facilities manager faces: what is typical commercial roof life expectancy? 


What is the life expectancy of a TPO roof? A thermoplastic Olefin (TPO) roof typically lasts as little as 22 years and up to a maximum of about 30 years. The two thermoplastic layers are adhered to a polyester scrim for reinforcement, becoming a single ply to protect your roof. 

TPO lasts so long because it can be compounded with a top coat that reflects heat and light, reducing your building’s cooling load. The reflectance also decreases degradation from ultraviolet light, a leading cause of premature roof decay. 

TPO sheets are connected through electric welding, to fuse the two pieces together into one piece, forming one long, continuous, waterproof seam. The seam is immediately tested by hand to ensure complete welding. 

If a highly qualified commercial roofer installs TPO, paying careful attention to methodical seam welding and mechanical fastening around parapets and HVAC curbs, your TPO roof can provide up to three decades of steady, dependable service. 

If that same commercial roofer performs annual or semiannual inspections, maintenance, and minor repairs, the roof will probably surpass all life expectancy planning, giving you bonus years during which you can plan for the next roof.  

Bituminous Membrane

What is the lifespan of a bituminous membrane roof? The life expectancies of this category of roofing (which relies on a tried-and-true product, asphalt, as the basic waterproofing material) vary, but warranties range from 10 to 20 years depending on the product, system, layers, and application. Bituminous roofing can be applied in many ways, including:

  1. Torch Down (or “Torch On”): This is the most common method of installing Bituminous Membrane roofing. Sheets of roofing are rolled onto the roof and then adhered to the surface using a hand-held propane torch.
  1. Hot Mop: A layer of molten asphalt is applied to the roof using a mop-like tool (hence the name), and the Bitumen roof is placed on top.
  1. Cold Application: Utilizes a cold adhesive as a safer alternative.
  1. Self-Adhered: The roofing is manufactured with a self-adhering membrane, simplifying the installation process for roofers.


How long does EPDM last on commercial roofs? EPDM rubber membrane roofing has a lifespan of 15 to 20 years, somewhat longer than TPO roofing. When installed and maintained properly, it can last up to 50 years. However, EPDM is not used in Southern California at all.

EPDM’s resilience is due to its synthetic rubber composition. It comprises a saturated polymer that enhances the rubber’s durability by providing resistance to heat, UV, ozone, and tearing. Additionally, adopting a thicker rubber membrane protects the roof from damage, particularly in more exposed areas. As a result, its lifespan will be longer.


How long does a PVC roof typically last? When properly maintained, polyvinyl chloride roofing can last between 20 and 30 years.

PVC roofs are constructed from two layers of thermoplastic materials and are chosen by many commercial properties due to their longevity. Welding the seams permanently bonds the layers together, strengthening the material.

It is resistant to water, chemicals, fire, and wind, but not heavy loads and impact. You should avoid walking on PVC roofing since it is prone to cracking and puncturing.

Metal Roof Life Expectancy

What is the average lifespan of a metal roof? In comparison to TPO roofing, which has a 20- to 30-year lifespan, a metal roof atop your commercial building will last significantly longer, depending on the type of metal utilized.

1. Galvanized steel: The zinc coating in a galvanized steel roof protects the material from minor scuffs and scratches, giving it a useful lifespan of up to 50 years. However, keep in mind that if left unpainted, the material will only last about 30 years, and salt spray will further reduce the lifespan.

2. Aluminized steel: Instead of zinc, this type of steel roofing is covered with aluminum. The metal forms a reflecting surface that helps prevent heat transfer to attics and acts as a physical barrier against corrosion. The usable life of an aluminum steel roof ranges from 20 to 40 years.

3. Galvalume: Its underlying steel is coated with zinc-aluminum alloy, providing long-lasting protection against the elements. While it is prone to corrosion in coastal areas, it reflects solar radiation, minimizing heat gain indoors. The average lifespan of this roofing material is 30 to 40 years.

4. Aluminum: When properly maintained, aluminum can last four decades or longer, similar to Galvalume. It is more expensive than Galvalume, but it is corrosion-resistant, lightweight, and ideal for coastal environments.

5. Copper: Consider copper if you want a roofing material that will last for generations. Because of its exceptional corrosion resistance, it can endure for more than 60 years. However, it is an expensive roofing material.

6: Zinc: Like copper, its lifecycle can reach up to six decades or even longer with proper maintenance. However, longevity comes at a relatively high price.  

Asphalt Shingle

What is the lifespan of a commercial asphalt shingle roof? A shingle manufacturer will offer a warranty for 30 to 40 years on commercial roofs, which is about how long you can expect the asphalt roof to last.

An asphalt roof that has a low slope is more prone to having water pool and soak through the underlayment, causing roof leaks. Other factors, such as the quality of the shingles and the frequency of maintenance, can also affect the life lifespan of a roof. Composite, organic, and fiberglass shingles all have their advantages, but fiberglass is the most long-lasting.

As part of your regular maintenance, apply Roof Maxx to your asphalt shingle roof to help it last longer. A single coating can extend the functional life of your roof by five years, delaying the need for a complete replacement.


Coatings are not a replacement for a structurally sound, well-insulated roof material. Coatings add years of life to a struggling roof, increase reflectivity, and boost water-resistance. They do not replace proper maintenance but can buy a facilities manager a year or two in which to plan and budget roof succession.

  • Acrylic Coatings: Particularly appropriate for areas with a lot of ultraviolet exposure from sunlight (as in Los Angeles), elastomeric coatings have a number of advantages, including:
  • Lower costs than other coatings
  • Highly reflective of ultraviolet rays, reducing chemical degradation and increasing heat reflectivity
  • Granule retention
  • Decreased cooling costs
  • Silicone Coatings: Quality silicone systems involve a thick primer base with a fully embedded polyester mesh, with silicone mastic applied at penetration using a three-course method with polyester, then a final thick coat of silicone; a system like that, properly installed, will last for up to 20 years offering advantages like:
  • Silicone is a waterproof product
  • It holds up well under ponding water in depressed areas
  • Silicone does not wear out or deteriorate

However, a disadvantage of silicone coatings is that, once you use silicone, there is no going back. You can only repair and coat with silicone in the future.

What is a Typical Warranty for a Commercial Roof?

Roofing warranties for commercial roofs are linked to roof life expectancy and vary from manufacturer to manufacturer. Here are some warranty ranges for common commercial roofing types:

  • TPO Warranties range anywhere from 15-30 years, depending on thickness, installation details, and some other technical factors. 
  • Asphalt shingle manufacturers give a 30-40 year warranty when installed on commercial roofs. 
  • Bituminous roofing warranties range anywhere from 10-20 years, depending on the product, system, layers, and application.

How Often Do Roofs Need to Be Replaced?

The frequency of replacing a property’s roofing depends on the material used and related roof life expectancy. For instance, in 50 years, you may need to replace your roof twice if it’s made with asphalt shingles.

However, the frequency may also be higher or lower for other reasons. The quality of installation, the frequency with which it is maintained, and the severity of weather conditions have an effect on whether you have to replace your roof more often.

How Do I Know if My Roof Needs to Be Replaced?

Remember that roof life expectancy is just a guide—it should not be your only basis in knowing when to replace your roofing.

Damage is one of the most obvious signs that your roof needs replacement. There are several types of roof damage, and each merits immediate attention to prevent bigger issues down the road.

Look out for water stains on your ceiling and walls, pest infestations indoors, and fungal growth in your property—these are indications of water intrusion, often through a leaky roof.  

What Happens if You Don’t Replace Your Roof?

You might be tempted to put off roof replacement to save money, but in doing so, you face the possibility of more widespread property damage.

A bad roof can collapse if it has a weakened underlying structure, causing you more extensive and expensive repairs. Moreover, a leaking roof is often the starting point of moisture damage inside your property.

What Type of Roofing Is Best in California?

Keeping in mind that every roof is different, and you should consult with an experienced roofing professional to discuss your unique needs and specifications, here are some of our recommendations for the best roofing types in California:

  • We usually see the best value from asphalt shingles on sloped roofs. 
  • For low slope and flat roofs, we generally see that TPO or PVC work well for larger roofs with minimum penetrations and future plans for alteration and traffic. 
  • For smaller low-slope roofs where alterations and foot traffic are expected, we generally like to go with a torch down system. 
  • We recommend using acrylic coating systems based on the age and condition of a roof, and it may be a great way to restore or prolong the life of your existing roof.

Making Your Choice

Your existing roof has taken away some choices for you. You may have inherited a building with a deteriorating single-ply membrane. You may be faced with a re-roof that is just barely in your company’s budget. What can you do?

To maximize your existing roof’s lifespan, partner with your local commercial roofer. Get a complete inspection performed, including photographs and videos to document existing conditions in these critical areas:

  • Internal drains
  • Scuppers
  • HVAC curbs
  • Flashing
  • Seams

Only after inspection should you and your roofer decide on a suitable roofing material to augment or replace your existing roof.

Roof Repair Specialist of Los Angeles is your local, reliable commercial roofer. We can handle maintenance and repairs for your commercial roof with equal skill. We also can install a new roof correctly, getting every part of the job right the first time. Give us a call today to get started.