Can You Re-Roof a Commercial Building Without Tearing Off the Old Roof?
If your commercial roof is leaking or just showing its age, you might be wondering: Can we install a new roof without removing the old one? The idea of re-roofing a commercial building is appealing—less mess, less money, and less downtime. But the truth is, not every roof is a candidate for this option.
At Weather Shield Roofing Systems™, we’ve been helping commercial property owners, managers, and investors make smart roofing decisions for over 40 years. In this article, we’ll walk you through the five most important things to know before deciding if re-roofing is the right solution for your building.
What Exactly Does “Re-Roofing” Mean?
Re-roofing a commercial building means installing a new roof system over the existing one—without a full tear-off. This can save you both time and money because you’re avoiding the labor and disposal costs that come with removing the current roof.
In the right situation, it’s a smart and cost-effective strategy to extend the life of your commercial roofing system.
Can You Legally Have More Than One Roof?
That depends on your current roof configuration. According to commercial building codes, you’re only allowed to have two roofing systems total. If your building already has two layers, you’ll need to remove at least one before installing another.
However, not all solutions count as a new “roof.” For example, a silicone roof coating is often considered maintenance, not a roofing system. That means you might still have options—even if you already have two layers.
Is Your Existing Roof in Good Enough Condition?
Re-roofing only works when the existing roof is in decent shape. Here’s a quick checklist to determine if your roof might qualify:
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Less than 25% to 40% of the insulation is wet or saturated
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Seams and flashings still have solid adhesion
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The roof has been reasonably maintained throughout its life
If there are widespread leaks, major seam failures, or large areas of soaked insulation, a full tear-off and replacement may be your only option.
What Are the Benefits of Re-Roofing Over Full Replacement?
When re-roofing is possible, it offers several big advantages for commercial property owners:
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Lower costs – You’ll likely only need to remove wet insulation instead of the entire system, cutting down on labor and landfill fees.
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Faster installation – Crews spend less time tearing off old material, which means less disruption to your building’s operations.
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Eco-friendly – Fewer materials go into landfills, and many re-roofing systems are compatible with energy-efficient upgrades. We believe in recyling in place to save you money and prevent excess waste.
Check out our Youtube video about recycling in place!
A re-roof can be a great way to protect your roof investment while staying on budget.
How Much Does It Cost to Re-Roof a Commercial Building?
Commercial re-roofing costs can vary depending on the type of roofing system you choose and the condition of your existing roof. Here’s a general range by system type:
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Single-ply (EPDM or TPO): $3.50 to $9.00 per square foot
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Metal roofing: $5.00 to $12.00 per square foot
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Silicone roof coating system: $2.00 to $4.00 per square foot
Additional price factors include:
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Amount of wet or damaged insulation
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Number of penetrations (vents, HVAC units, etc.)
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Desired R-value for energy performance
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Whether you need to improve drainage or slope
The best way to get an accurate cost is with a professional roof inspection, which we’re happy to provide.
How Do I Know What’s Best for My Commercial Roof?
We get it—every building is different. Some roofs are great candidates for re-roofing, and others are better off with a full tear-off. That’s why it’s so important to work with a contractor who knows commercial roofing systems inside and out.
At Weather Shield Roofing Systems™, we never push a one-size-fits-all solution. Instead, we help building owners weigh the pros, cons, and long-term performance of re-roofing vs. replacement, so you can make the best decision for your property and your budget.
We believe in transparency, education, and doing what’s right for your building—always.
If you’re unsure whether your roof is eligible for a re-roof, or if you’re ready to talk through your options, reach out to us! We’d be glad to help.
Troy McClure
Account Executive
Troy McClure has been part of the Weather Shield team since 2021, bringing a strong relationship-focused and consultative approach to helping clients manage their roof assets. With a background in risk management, he offers a unique perspective on addressing roof leaks, preventative maintenance, and roof design. Troy values being part of a team and culture at Weather Shield that works together to help both clients and team members thrive in work and in life.
