What Is a TPO Roof?

If you're exploring commercial roofing options, you've likely asked yourself: what is a TPO roof and how does it compare to other materials? At Riverside Roofing LLC, we specialize in commercial roofing solutions, and this guide will walk you through the critical aspects of TPO roofing—its composition, performance, installation process, costs, and long-term value.

What Is a TPO Roof?

TPO, or Thermoplastic Polyolefin, is a type of single-ply roofing membrane composed of a blend of polypropylene and ethylene-propylene rubber. Designed for flat and low-slope roofs, TPO is a high-performance solution known for its durability, energy efficiency, and ease of installation.

Chemical Composition

The core of TPO lies in its polymer chemistry. It combines polypropylene and ethylene-propylene rubber to create a material that is flexible yet tough. Additives like UV stabilizers, flame retardants, and antioxidants are mixed in during production to boost weather resistance, reduce aging, and improve safety performance.

History and Industry Growth

Introduced in the early 1990s, TPO was created to bridge the gap between the affordability of EPDM and the durability of PVC. Since then, it has become one of the most widely used commercial roofing systems in North America. Its market share has steadily grown thanks to its reflective properties and proven performance in diverse climates.

Common Applications

TPO is primarily used in:

• Industrial warehouses
• Retail centers
• Hospitals and schools
• Multifamily and mixed-use buildings
• Office complexes and government structures

What Makes TPO a Single-Ply Membrane Roofing System

Unlike multi-ply systems that involve several layers of material, a single-ply membrane consists of a single layer of synthetic material that is rolled out across the roof surface.

Distinction from Multi-Ply Systems

Single-ply systems like TPO are thinner but more flexible. They're faster to install, involve fewer materials, and have simpler repair protocols. Multi-ply systems often require additional adhesives and layers, which increases labor and installation time.

Comparison with Other Single-Ply Membranes

• EPDM (Ethylene Propylene Diene Monomer) is a rubber-based membrane that comes in black, which can absorb more heat.
• PVC (Polyvinyl Chloride) is chemically resistant and durable but generally more expensive. TPO balances cost, energy efficiency, and flexibility better than most alternatives.

TPO for Flat and Low-Slope Roofs

The membrane's flexibility makes it ideal for structures where ponding water, thermal expansion, or material movement are concerns. It performs especially well in environments with strong sun exposure due to its reflective surface.

If you're wondering what is a TPO roof best suited for, it’s these flat or low-sloped systems that benefit the most.

Core Components of a TPO Roofing System

A complete TPO system is more than just the membrane. It’s a system engineered to perform under a range of stresses.

Membrane Layer

This is the primary waterproofing and UV-resistant surface. It resists tears and withstands harsh conditions without deteriorating quickly.

Reinforcing Scrim

The scrim is a woven or non-woven fabric embedded in the membrane to give it tensile strength and improve puncture resistance.

Additional Layers

Some TPO systems may include:

• Fire-retardant barriers
• Vapor barriers
• Insulation-compatible substrates
• Anti-oxidation coatings These elements are tailored to the building's needs.

TPO Roofing Thickness Options and Sizes

TPO membranes come in various thicknesses and roll sizes, offering choices based on durability requirements.

Common Thicknesses

• 45 mil (1.1 mm): Entry-level for standard use
• 60 mil (1.5 mm): Most popular for durability and warranty balance
• 80+ mil (2.0 mm+): Best for high-performance or extreme conditions

Standard Widths

TPO membranes are manufactured in widths of 10, 12, or 20 feet, allowing for faster installations and fewer seams.

Why Thickness Matters

Thicker membranes:

• Last longer
• Handle foot traffic better
• Withstand weather and UV degradation longer
• Provide longer warranties and better ROI

In determining what is a TPO roof's ideal thickness, consider building size, use case, and exposure levels.

TPO Roofing Installation Process (Step-by-Step)

At Riverside Roofing LLC, our experienced team follows a precise protocol to ensure proper installation.

Substrate Preparation

The existing roof is inspected, cleaned, or removed. Damaged decking is replaced. Smooth, debris-free surfaces are essential for adhesion.

Insulation Layer Installation

We offer three insulation options:

• Polyiso: Highest R-value per inch
• EPS (Expanded Polystyrene): Most affordable, doesn’t retain water
• XPS (Extruded Polystyrene): Mid-range in cost and moisture resistance

Attachment Methods

• Mechanically Fastened: Most common, economical
• Fully Adhered: Ideal for wind uplift zones or aesthetic surfaces

Seam Welding

A hot-air welding tool fuses overlapping seams, creating a watertight bond that’s stronger than the membrane itself. This ensures durability in TPO single-ply applications.

Flashing and Penetrations

Areas around vents, HVAC units, and pipes are sealed using custom-fitted flashings welded to the membrane. These details are crucial in maintaining the integrity of TPO roofs.

TPO Roof Costs and Pricing Factors

As of 2025, the cost to install a TPO roofing system ranges from $6 to $12 per square foot.

Cost Drivers

• Roof size and complexity
• Type and thickness of membrane
• Insulation choice
• Existing roof condition
• Warranty length and type
• Number of roof penetrations

Long-Term Savings

TPO's reflective surface reduces heat gain, lowering energy costs. Over the lifespan of a roof, these savings can significantly offset the upfront investment. Choosing energy-efficient TPO products can also reduce operational costs.

Clients who want a clearer understanding of what is a TPO roof in cost-benefit terms should focus on long-term operational savings.

Key Advantages of TPO Roofing Systems

TPO is popular for good reason. Here’s what makes it a standout choice:

• Reflects UV Rays: Reduces cooling load and energy bills
• Fire-Rated Options: Meets Class A fire ratings with additives
• Seam Strength: Hot-air welding creates leak-resistant seams
• Fast Installation: Lightweight and available in wide sheets
• Flexible Material: Handles structural movement and expansion
• Aesthetic Flexibility: Available in white, gray, and black to suit building designs
• Enhanced resistance to punctures and weathering over time

Limitations and Considerations of TPO Roofing

While TPO is a high-performing system, there are caveats to keep in mind.

UV Sensitivity

Early-generation TPOs degraded under prolonged high-heat exposure. New formulations have improved, but performance can still vary by manufacturer.

Longevity Concerns

Chemical formulations have evolved, so long-term durability is still being evaluated across generations of product.

Reflectivity Loss Over Time

TPO roofs, especially white ones, can accumulate dirt and lose reflectivity, reducing energy savings.

Maintenance Is Key

Annual inspections and minor repairs can extend the roof’s life and maintain energy performance.

Part of knowing what is a TPO roof involves understanding its vulnerabilities and maintenance requirements.

How Long Does a TPO Roof Last?

TPO roofs generally last 15 to 30 years, depending on several factors:

• Proper installation
• Thickness of membrane
• Environmental conditions
• Ongoing maintenance
• Selection of high-quality TPO membranes

If you're evaluating what is a TPO roof in terms of investment, its lifespan is a critical metric to consider.

Repairing a TPO Roof: What You Should Know

Typical Issues

• Seam separations
• Flashing cracks or dislocations
• Membrane punctures

How to Spot Problems

Look for signs like interior leaks, blisters, or surface damage. Moisture trapped under the membrane is a common cause of failure.

Advanced Diagnostics

Infrared scanning can detect moisture intrusion by highlighting temperature anomalies under the membrane, indicating wet insulation.

Evaluation Criteria

• Saturation percentage of insulation
• Membrane age
• Seam integrity
• Number of existing roof layers
• Suitability for silicone restoration

Knowing what is a TPO roof doesn’t stop at installation. Awareness of how to maintain and repair it is essential.

TPO Roof Repair Options Based on Saturation Levels

If Insulation Is Less Than 25% Saturated

• Remove and replace wet areas
• Power wash the surface
• Reinforce seams
• Apply silicone restoration coating
• Extend lifespan with a new warranty

If Saturation Exceeds 25%

• Complete tear-off may be required
• If only one layer exists: apply spray foam roofing over a cover board
• For two or more layers: full removal followed by new TPO system installation
• Consider switching to more resilient membrane systems if needed

When to Consider Spray Foam

If your existing TPO system is beyond restoration and you want seamless insulation, spray foam roofing can provide waterproofing and thermal performance in one application.

Understanding what is a TPO roof compared to its alternatives is key to selecting the right system.

Environmental and Energy Efficiency Benefits of TPO Roofing

TPO systems contribute to green building goals in several ways:

• Cool Roof Technology: Reflects solar energy, reduces heat absorption
• Energy Star Rated: Meets or exceeds government energy standards
• LEED Credit Potential: Can contribute to building certifications
• Recyclability: Old membranes can be reused or recycled
• Suitable for use in sustainable commercial systems

Choosing the Right TPO System for Your Commercial Building

At Riverside Roofing LLC, we take a comprehensive approach to roofing.

• We evaluate your structure, insulation needs, and environmental conditions
• Recommend the right thickness, attachment method, and add-ons
• Use only manufacturer-approved installation techniques
• Focus on long-term durability and performance

We install modern TPO systems including UltraPly TPO and other trusted TPO products that meet rigorous roofing system requirements.

Final Thoughts: Is TPO Right for Your Building?

What is a TPO roof? It’s a cutting-edge roofing solution that blends affordability, strength, and sustainability. Whether you’re replacing an aging roof or building new, TPO is a smart choice for commercial properties that prioritize performance and cost control.

Work with a roofing contractor who understands the full picture. Choose Riverside Roofing LLC to guide you every step of the way—from consultation to completion.

Contact Riverside Roofing LLC

Why Trust Us?

At Riverside Roofing LLC, we’re proud of the work we do. Helping building owners protect their investment is more than a job—it’s our passion.

You can count on our crew of local roofing contractors because we:

• Have over 35 years of experience
• Are certified GAF Master Elite® roofers
• Offer enhanced warranty protection
• Use high-quality materials designed to last
• Provide competitive pricing and financing
• Always return your calls within the same day

If your commercial roof is leaking, aging, or showing signs of wear, we have the tools and experience to restore or replace it. No roof is too big or too complex for our expert crew.

Trust the roof over your head. Schedule your free estimate today.

Call us at (425) 600-2750, or fill out our online contact form to get started.