Choosing the right roofing system is one of the most important decisions for any commercial or industrial building owner — especially in a climate like Chicago, where your roof faces high winds, snow, rain, and wide temperature swings throughout the year.
Two of the most commonly used flat roofing systems in the Chicagoland area are TPO (Thermoplastic Polyolefin) and Modified Bitumen. Each has its strengths and ideal use cases — and this post breaks down the key differences so you can make the best choice for your property.
What Is TPO Roofing?
TPO is a single-ply membrane roofing system made from thermoplastic materials. It’s white (highly reflective), lightweight, and usually heat-welded at the seams.
✅ Pros:
- Energy-efficient: Reflects sunlight and reduces cooling costs
- Highly durable: UV-resistant, puncture-resistant, and flexible
- Heat-welded seams: Creates a watertight seal
- Low maintenance
⚠️ Considerations:
- May be more expensive than modified bitumen initially
- Requires skilled labor for proper heat-welded installation
What Is Modified Bitumen Roofing?
Modified Bitumen is an asphalt-based, multi-ply roofing system reinforced with modifiers like SBS or APP. It’s often applied in layers and may be torch-applied, cold-applied, or self-adhered.
✅ Pros:
- Excellent durability and resistance to foot traffic
- Proven track record in harsh climates
- More forgiving installation methods (vs. TPO heat-welding)Multiple application options (good for complex roofs)
⚠️ Considerations:
- Absorbs heat: dark surface increases cooling costs
- Seams are sealed with adhesives or torches (less watertight than heat-welded)Heavier and more labor-intensive
Which One Is Right for Your Building?
📍 Choose TPO if:
- You want a cool roof to lower energy costs
- Your building needs a lightweight solution
- Reflectivity and sustainability are priorities
- You're working with a qualified roofing contractor who can properly heat-weld seams
🏢 Choose Modified Bitumen if:
- Your building has heavy foot traffic (like rooftop access or equipment)
- You need multi-layer protection and proven performance
- Your roof is irregularly shaped or complex
- You're working within a more limited budget
✅ Need Help Deciding?
At TECHO Roofing, we install both TPO and modified bitumen systems throughout the Chicago and Chicagoland area. Whether you manage a warehouse, office building, school, or retail space — we’ll help you choose the best flat roofing solution for your needs and budget.
As a certified MBE roofing contractor in Illinois, we also support public projects and general contractors looking to meet participation goals.
📞 Contact us today to request a consultation or proposal for your flat roof project.
