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. Bituminous roofing can be applied in many ways: 

  1. Rolled Roofing — This material, which is a bit like long sheets of shingles, lasts around 10 years; it requires diligent maintenance but is a traditional, torch-down material with a high degree of reliability
  2. Built Up Roofing (BUR) — Many layers of asphalt-coated, industrial fabrics are covered with granulated materials such as crushed stone; BURs can last anywhere from 20 to 30 years and have been proven roofing technology for over 100 years
  3. Modified Bitumen (Mod Bit) — Mod Bit roofs, which last around two decades, use base plies and a cap sheet; they share waterproofing benefits of BUR roofs and are high customizable, with cap sheets surfaced to either provide increased weather resistance or extra reflectivity to reduce cooling costs
  4. SBS Membranes — Styrene-Butadiene-Styrene (SBS) roofs use bitumen modified with elastic polymers (SBS) to form a synthetic rubberized asphalt coating; the strengthened coating is applied to Fiberglas® to increase tensile strength and boost dimensional stability in a material normally lasting up to 50 years
  5. APP membranes — Bitumen modified with plastic Atactic Polypropylene (APP) polymers create a tough, durable roof material; APP bituminous membranes have a high temperature tolerance and a life expectancy of 20 to 25 years 


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

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.

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