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How Much Does a New Commercial Roof Cost? 

One of the most common—and most understandable—questions we hear in the commercial roofing industry is: “How much will my new roof cost?” 

It seems like it should be a straightforward answer. But the truth is, the cost of a new commercial roof depends on a wide range of variables. Some of these are visible when you’re standing on the roof. Others are hidden beneath the surface but can have an even greater impact on the final price. 

At Weather Shield Roofing Systems™, we’ve been guiding commercial building owners, property managers, and investors through these decisions for over 40 years. In this blog, we’ll break down the major factors that affect the cost of a new roof—so you can move forward with clarity and confidence. 

The Visible Components: What You Can See from the Roof

Let’s start with what’s most obvious—the things you can see when you’re standing on the roof. These make up a large part of your roofing investment, and they include:

1.) Roofing Material Type

The first and biggest driver of cost is the type of roofing material you choose. Each has its own pros and cons. Most low-slope commercial roofs use one of three main membrane types: 

• EPDM (rubber) – known for its durability and flexibility 

• TPO (thermoplastic polyolefin) – popular as a cost effective, energy efficient solution.

• PVC (polyvinyl chloride) – strong, chemical-resistant, and highly reflective 

2. Material Thickness and Warranty Length

With low-slope roofing, the thicker the membrane, the longer it lasts—and the longer the warranty. 

• 45 mil membranes: typically offer a 15-year warranty 

• 60–90 mil membranes: may offer 20- to 30-year warranties 

The price difference between a 15-year and a 30-year membrane is often $1 to $2 more per square foot. That might not seem like much, but it adds up quickly—and it’s a strategic investment if you plan to own or manage the building long-term.

2.) Roof Complexity

Next, consider how “busy” the roof is. A wide-open roof is faster and cheaper to install. But roofs with lots of features—like skylights, HVAC units, walls, drains, or multiple corners—require more materials, more labor, and more detail work. 

The more penetrations, slope changes, and transitions on your roof, the more complex (and costly) the installation becomes.

3.) Attachment Method

All roofing systems need to be attached in some way. There are three common methods: 

• Fully adhered – glued down for maximum wind resistance 

• Mechanically fastened – screwed in place through the insulation 

• Ballasted – held down by gravel or pavers 

Each method has its pros and cons, and the best choice depends on your building’s structure, location, and long-term goals. We cover this more in our blog: Which Flat Roof Attachment Method is Right for Your Commercial Roof? 

The Hidden Components: What’s Beneath the Surface?

This is where things start to get more complicated—and where costs can climb quickly. The condition and composition of your roof assembly (everything underneath the membrane, including insulation and structure) can significantly influence the final price.

Multiple Roof Layers:

For example, if your building already has two existing layers of roofing, building codes require that all layers be completely removed before a new one can be installed. This matters because tear-offs are labor-intensive, time-consuming, and involve additional disposal costs. As a result, a roof that requires full removal will almost always be more expensive than a qualified “recover” job. Check out our blog: What to Know About Roofing Code Requirements Before Replacing Your Commercial Roof 

Insulation Requirements and Condition:

In addition to roof layers, commercial roofs must also meet minimum energy performance standards. Most jurisdictions require at least R-20 insulation, while some mandate R-30 depending on the building type and use. If your existing insulation doesn’t meet code, you may need to add more. However, here’s the real catch—if the insulation is wet, it must be removed and replaced.

Why? Because wet insulation compromises energy performance, traps moisture, and can lead to long-term roof damage. Unfortunately, you can’t tell if insulation is wet just by looking at it. That’s why we use non-destructive testing tools such as infrared scanners and nuclear moisture meters. These tools allow us to pinpoint problem areas without having to tear up the entire roof.

Roof Deck Condition:

Finally, another hidden—but critical—component is the roof deck itself. This structural layer beneath the insulation supports your entire roofing system. If we find rot, rust, or other structural damage, those sections must be replaced before any new materials go on. While this adds to the cost, it’s necessary to ensure safety and long-term performance.

Want to dig deeper into this topic? Check out our related blog: What Is a Roof Deck, and Why Does It Matter? 

So… What Does That Mean for Your Roofing Budget?

Taking all these factors into account, the cost of a new commercial roof can vary widely. Here’s a ballpark: 

• Simple recover over one existing layer, with minimal detail and no structural issues: $4-$6 per square foot 

• Full tear-off, with R-30 insulation, complex detailing, and roof deck repairs: $20–$30+ per square foot 

In other words, the price from one extreme to the other isn’t just double—it can be three or four times higher, depending on what we uncover during the assessment. 

If you’re trying to understand where your building fits on that spectrum, we’re here to help. At Weather Shield Roofing Systems™, we’re committed to transparency, education, and helping our clients make smart, cost-effective decisions for their roofs. Contact us today!

Nate Bush

Sales Director

Nate Bush brings over 20 years of experience in the commercial roofing industry, all with Weather Shield Roofing Systems. A graduate of Davenport University with a focus in entrepreneurship, Nate combines his industry expertise with strong leadership skills to head Weather Shield’s sales department. His deep knowledge of roofing solutions and commitment to customer service help drive the company’s growth and deliver exceptional value to clients.