Why Blazeguard Plywood Needs to Be Replaced: What Homeowners and Contractors Should Know
Blazeguard plywood has been a popular fire-retardant roof and wall sheathing material in both residential and commercial construction. Known for its chemical treatment that slows flame spread, Blazeguard has been widely used to meet building code requirements—especially in multi-family housing and buildings in wildland-urban interface zones. But over the past several years, more builders, inspectors, and homeowners are asking a critical question: Does Blazeguard plywood need to be replaced?
The short answer: In many cases, yes. Here’s why.
What Is Blazeguard Plywood?
Blazeguard is a fire-retardant treated (FRT) plywood made by coating standard plywood sheets with a magnesium oxide-based formula. It’s intended to offer enhanced fire resistance, especially in roof and wall sheathing applications. It is typically installed with the treated side facing inward (toward the attic or interior space) to meet fire codes.
Why Blazeguard Plywood Fails
Despite its initial advantages, Blazeguard plywood has been associated with several durability issues that can compromise the integrity of the structure over time.
1. Delamination and Surface Flaking
One of the most reported problems with Blazeguard is delamination—when the fire-retardant coating separates from the wood panel. In some cases, entire sheets deteriorate, with the treated surface flaking off and exposing the raw wood underneath. This compromises both the fire resistance and the structural integrity of the panel.
2. Moisture Sensitivity
Blazeguard is highly sensitive to moisture, especially during construction. If exposed to rain, humidity, or even condensation in an attic space, the panels can degrade prematurely. Once moisture is absorbed, the panels may warp, swell, or crumble—prompting the need for full replacement.
3. Code Compliance Issues
If the Blazeguard has deteriorated, it may no longer meet local or national fire safety codes. This could affect insurance coverage, building inspections, and even the resale value of the home.
Signs Your Blazeguard Plywood Needs Replacement
If you suspect your home or project used Blazeguard sheathing, look out for the following warning signs:
- Visible surface powdering or coating flakes
- Crumbling or soft spots in the plywood
- Mold or mildew growth on or behind the panels
- Sagging sheathing in the attic or roof deck
- Roofing leaks or moisture accumulation
A licensed contractor or building inspector can help confirm whether the material has failed and if a full or partial replacement is needed.
The Risks of Ignoring Blazeguard Problems
Leaving damaged Blazeguard in place can lead to serious structural and safety risks, including:
- Loss of fire-retardant protection
- Increased risk of mold and indoor air quality issues
- Compromised roofing system
- Potential insurance claim denials
In some jurisdictions, building code violations due to failed fire-retardant materials can result in fines or mandatory repairs.
What to Use Instead of Blazeguard
If you’re replacing Blazeguard, consider safer and more durable alternatives like:
- CDX plywood with fire-retardant treatment from trusted brands like Pyro-Guard® or Dricon®
- OSB panels with factory-applied coatings tested for moisture resistance
- Gypsum-based sheathing for walls (e.g., DensGlass® or Securock®)
Always choose materials that are approved for your specific local building codes and climate conditions.
Final Thoughts
Blazeguard plywood was once seen as a reliable solution for fire-resistant construction, but real-world performance has exposed serious shortcomings—especially regarding moisture resistance and long-term durability. If your structure contains Blazeguard sheathing that’s showing signs of failure, don’t wait. Replacing it now can prevent more extensive damage, keep your building up to code, and preserve the safety of the occupants.
Need help with a replacement or inspection? Contact a licensed contractor or building professional who specializes in roof and attic retrofits.
Here at Eiseman Construction, we offer a variety of services that will help you to extend the life of your roof, siding, and gutters. It is important to keep up with preventative maintenance in order to keep your home in good shape. Click here to get in contact with us for any exterior repair work that you may need!
