Based on the comparison between the two systems, the TPO (Thermoplastic Polyolefin) roofing system generally has a longer lifespan in British Columbia’s climate.

Here is a breakdown of the typical lifespans for both systems according to the provided content:

• TPO Roofing: This system typically lasts 20 to 30 years when installed correctly and properly maintained. It is noted for its high reflectivity, energy efficiency, and heat-welded seams, which perform well in Vancouver’s wet conditions.
• Torch-On (Modified Bitumen): This system has a typical lifespan of 15 to 20 years. While it offers superior puncture resistance and is proven in high-rainfall climates, it generally requires more frequent maintenance, such as recoating every five to seven years to counter UV degradation.

Regardless of the material chosen, professional installation and proactive commercial roofing maintenance in Vancouver—such as annual inspections and ensuring proper drainage—are the most critical factors for maximizing the lifespan of any flat roof membrane.