Why Does My New Roof Look Wavy? Common Causes and Long-Term Concerns For A Wavy Roof On A New Construction Home.

A Wavy roof deck can be hard to convey in pictures but looking at it from this angle can help identify the issue.

If you’ve recently bought a new construction home in Northeast Florida and noticed that the roof looks wavy or uneven, you’re not imagining things—and it’s not something to ignore. At Hanna Home Services, we inspect a lot of new build homes across Jacksonville, Orange Park, Starke, and surrounding areas, and this is one of the most common issues we flag early on.

So, what causes a wavy roof on a brand-new house, especially when it’s using 3-tab shingles and OSB roof sheathing? Let’s break it down in simple terms.

1. OSB Roof Sheathing Swelling from Moisture

Most new homes are built with OSB (Oriented Strand Board) for roof decking. While OSB is strong and affordable, it’s also highly susceptible to moisture. If it gets wet during construction—maybe from rain or high humidity—and is nailed down before it dries, it can swell. Once those panels dry out later, they often stay raised or warped, creating permanent waves in the roof.

🛠 Long-term impact: A wavy roof surface leads to poor water drainage and premature wear on shingles. It can also void the manufacturer’s warranty on roofing materials if the decking wasn’t properly installed.

2. Uneven Trusses or Rafters

The roof decking sits on top of the home’s framing. If the trusses or rafters aren’t level or installed incorrectly (like if the crowns are all facing up), the OSB panels will follow that uneven shape. When the shingles go on top, every dip and hump shows.

🛠 Long-term impact: Shingles wear out faster in areas with poor drainage. Over time, water pooling can lead to leaks, wood rot, or mold.

3. Improper Fastening or Spacing of OSB Panels

Fasteners that miss the framing members or are spaced too far apart can let the OSB flex or lift over time. Builders rushing to complete projects sometimes cut corners, and unfortunately, the roof ends up paying the price.

🛠 Long-term impact: Loose sheathing shifts over time—especially under Florida’s strong winds—causing roofing material failure and increasing the risk of wind-driven rain intrusion.

4. Thin 3-Tab Shingles Show Everything

A lot of new homes in Jacksonville and surrounding areas are roofed with 3-tab asphalt shingles because they’re cost-effective. But here’s the downside—they don’t hide imperfections. They’re thin and lay flat, so any unevenness in the sheathing underneath shows right through.

🛠 Long-term impact: Cosmetic at first, but over time, waves create stress points where shingles can crack or lift, leading to early roof failure.

5. OSB Didn’t Acclimate Before Installation

Building materials, especially wood products like OSB, should be allowed to acclimate to local temperature and humidity before being installed. When that doesn’t happen—which is common when builders rush to beat deadlines—the sheathing can expand after it's already nailed down, leading to buckling and warping.

🛠 Long-term impact: The result? Shingles buckle, warranties are voided, and the homeowner inherits the problems.

What Should Homeowners and Realtors Do?

If you’re buying or selling a new construction home in Northeast Florida, a professional home inspection is your best defense against long-term roof issues. Even small waves in the roof can be a sign of larger structural shortcuts or moisture problems beneath the surface.

At Hanna Home Services, we specialize in inspecting new homes throughout Jacksonville, Clay County, and surrounding areas. Our certified home inspectors are trained to catch these issues early—before they turn into expensive repairs.

✅ We Check for:

• Proper OSB installation and spacing

• Roof deck flatness and truss alignment

• Shingle type and condition

• Moisture intrusion and ventilation issues

  
  
  
  
  
  

One Call, One Appointment, Complete Peace of Mind

We know how frustrating it is to deal with builder issues after closing. That’s why we offer same-day inspection reports, Supra access for convenience, and multiple services in one visit—including roof inspections, 4-point inspections, and wind mitigation reports at no extra cost.

If you’ve spotted a wavy roof on your new home or want peace of mind before closing, book your inspection with Hanna Home Services today.

📍 Serving Jacksonville, Orange Park, Starke, Middleburg, Lake Asbury, Green Cove Springs, and beyond.

👉 Schedule Online Now📞 Or call/text us at (904) 658-1009