The Slow Decline of Modified Bitumen Roofing: What You Need to Know in 2025

The Changing Landscape of Commercial Roofing

Modified bitumen roofing, or ModBit, has long been a staple in the commercial roofing industry. It earned a reputation for durability and toughness, especially when properly installed. However, in recent years, we’ve seen a steady decline in its popularity.

As a flat roof repair specialist, with 17 years of experience in commercial roofing, I’ve worked extensively with ModBit systems. While I still have great respect for their performance, it’s clear that the roofing industry is evolving. In this article, I’ll explain why ModBit is losing ground, what’s replacing it, and how modern restoration solutions—like silicone coatings—can breathe new life into aging roofs.

What Is Modified Bitumen Roofing?

Modified bitumen is a multi-layer roofing system made from asphalt-based materials that are either:

Torched down using heat to bond layers, or
Mopped down with hot asphalt.

Its layered construction provides exceptional strength, making it ideal for flat or low-slope roofs that face harsh weather conditions.

Why Was ModBit Popular?

Durability – Properly installed ModBit roofs can last 20–30 years.
Thick Membrane – Handles ponding water better than thinner single-ply systems like TPO.
Proven Performance – Historically reliable in areas with high foot traffic or heavy mechanical equipment.

Despite these advantages, ModBit has been gradually losing market share—and here’s why.

Reasons for the Decline of Modified Bitumen Roofing

1. Competition from Single-Ply Roofing Systems

Single-ply membranes like TPO (Thermoplastic Polyolefin), PVC, and EPDM have taken the roofing industry by storm.

TPO dominates the market—affordable, lightweight, and simple to install.
Thickness flexibility—TPO membranes are available in 45 mil, 60 mil, and 80 mil options, making them adaptable to different needs.
Faster installation reduces labor costs significantly.

Downside of TPO?
While TPO offers cost and efficiency benefits, it can struggle with ponding water, especially in low-slope applications—an area where ModBit excels.

2. Rising Labor Costs and Skilled Labor Shortage

Installing ModBit roofs requires specialized skills:

Torching or mopping demands highly trained crews.
Safety concerns—Working with hot asphalt or torches adds risk.
Labor shortages—Fewer contractors specialize in ModBit installations, driving up costs.

In contrast, single-ply systems require less training and are faster and cheaper to install, making them more appealing in today’s labor market.

3. Material Costs and Supply Chain Challenges

Since the COVID-19 pandemic, supply chain disruptions have affected roofing materials across the board. However, ModBit has been hit particularly hard:

Raw material shortages increased costs.
Competition for materials globally drove prices higher.

Meanwhile, single-ply membranes have become more affordable and accessible, making them the go-to choice for new construction and re-roofing projects.

Modified bitumen roofing — **Manufacturer Defect in Modified Bitumen Roofing**

4. Technological Advancements in Roof Restoration

The rise of liquid-applied roofing membranes—like silicone coatings—is another reason for ModBit’s decline.

These systems offer:

Cost-Effective Restoration – Extends the life of aging roofs without a full replacement.
Durability – Handles ponding water and UV exposure exceptionally well.
Flexibility – Suitable for various roof types, including ModBit, metal, and single-ply systems.
Warranties – Often come with 10–20-year warranties, providing peace of mind at a fraction of the cost.

5 Powerful benefits of Metal Roof Restoration!

The Ultimate Guide to Commercial Roof Inspection

Is Modified Bitumen Roofing Dead?

Absolutely not. ModBit still holds a niche position in the roofing market, especially in areas with extreme weather conditions and heavy foot traffic.

Strengths of ModBit:

Thicker Material – Withstands ponding water better than TPO or PVC.
Layered Protection – Built-in redundancy makes it more resilient to punctures and damage.
Long Lifespan – Proven durability when properly maintained.

However, the reality is that TPO, PVC, and liquid-applied coatings are now the preferred choices for most commercial roofing projects—especially here in Houston, Texas, where heat and humidity make ModBit installations a grueling task.

The Future of Roof Restoration: Silicone Coatings

At Commercial Roof Repair Solutions, we often recommend silicone roof restoration for aging ModBit roofs.

Jaw Dropping Facts About Commercial Roof Coatings!

Why Silicone Roof Restoration Is a Game-Changer:

Cost Savings – Avoids costly tear-offs and replacements.
Seamless Protection – Eliminates seams that can fail over time.
Waterproof – Ideal for flat roofs with ponding water issues.
Eco-Friendly – Reflective surfaces reduce energy costs and heat absorption.
Longevity – Extends roof life by 10–20 years with minimal maintenance.

When to Replace vs. Restore Your ModBit Roof

Signs It’s Time to Restore (Save $1,000’s):

Minimal leaks and minor repairs needed.
No more than 20% patching visible.
Drains well without severe ponding.

Signs It’s Time to Replace:

More than 20% of the surface is patched.
Poor drainage and standing water for over 48 hours.
Extensive cracking or membrane separation.

Final Thoughts: Choose What’s Best for Your Roof

While modified bitumen roofing is becoming less common, it’s still a solid option in certain situations. However, for most commercial buildings in Houston and the surrounding areas—like Sugar Land, Pasadena, and The Woodlands—we’re seeing a clear shift toward single-ply systems and liquid-applied coatings.

If you have an aging ModBit roof, don’t rush to replace it! A silicone roof restoration may be the smarter, more cost-effective solution.