You just invested in a brand-new roof, but when you pull into the driveway, something looks wrong. The shingles look rippled, bumpy, or “wavy.”
Homeowners often panic, thinking they received a bad installation. While a wavy roof can be a sign of a problem, it can also be a temporary settling issue. Here is how to tell the difference.
Cause 1: Oil Canning or Thermal Shock
Just like a metal baking sheet pops in a hot oven, roofing materials expand and contract with heat.
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The Scenario: If your roof was installed on a cold day and then heated up quickly, the shingles might ripple temporarily.
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The Fix: Often, this resolves itself after a full season of warm weather helps the adhesive seal settle.
Cause 2: Wet Underlayment (The “Wrinkle”)
Shingles sit on top of a layer of felt paper or synthetic underlayment. If this layer got wet during installation (or from high humidity), it can wrinkle.
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The Fix: This is tougher to fix. If the wrinkles are severe, it might require removing the shingles in that area to flatten the felt.
Cause 3: Improper Decking Spacing
Plywood roof decking needs a small gap between sheets to expand. If the installer jammed them together tight, the wood will buckle when it gets humid, pushing the shingles up.
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The Verdict: This is a structural issue. If you suspect your decking was installed incorrectly, you need a professional inspection immediately to check the attic structure.
Should I Be Worried?
If your roof is curling or buckling at the edges, that is a failure. But if it is a gentle wave in the middle of a shingle, it might settle.
Unsure if your wavy roof is normal? Contact Utz Roofing. We will perform a warranty inspection to give you peace of mind.
