4 Reasons Your New Roof’s Shingles Look Wavy—And What to Do About It

Leah Lopez Cardenas
Reviewed by Ami Feller
Updated March 29, 2022
Big suburban home with stone siding
Photo: Stephen VanHorn / Adobe Stock


  • Shingles on a new roof may look wavy at first, but shouldn’t last longer than a few days

  • Plywood or felt problems, expansion, misalignment, or poor craftsmanship could be the cause

  • If your contractor’s quality is the problem, you can ask them to investigate and re-do the work

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If you recently hired a roofing contractor to install a new roof or complete a roof repair, it's only natural you want the final product to look perfect. So it may be disheartening to look up and ask yourself, "Wait, why do my new roof shingles look wavy?" If you notice that your new shingles look wavy, don't panic—there are a few reasons it's normal, and a few ways to fix it. 

Read on for the low down on wavy roof shingles, and what to do about them.

Shouldn't My Shingles Lay Flat?

Shingles will normally look a little lumpy when first installed, but within a couple of warm days, they should lay flat. It is not normal for new shingles to look wavy for more than a few days and if this is the case for your roof, contact your contractor to discuss it.

What Causes New Roof Shingles to Look Wavy?

closeup of a worker installing roof shingle
Photo: brizmaker / Adobe Stock

A few culprits cause shingles to look wavy or rippled, including problems with the plywood or felt underneath the shingles, issues with expansion in extreme temperatures, misaligned shingles, or just generally poor craftsmanship.

1. Improper Framing or Sheathing

Sheathing is a series of wooden 4 foot by 8 foot rectangles, often made of OSB or plywood, that carpenters or roofers attach to the house’s frame (joists and trusses). This layer of wood is used to attach the roof’s shingles. Ripples can happen if the sheathing is installed without a gap between the boards to allow for expansion and contraction, or if the builder left the sheathing exposed to the elements for too long without covering it with a protective underlayment. If this is the problem, look for ripples spaced evenly 4 to 8 feet apart (to match the spacing of the plywood).

If the plywood beneath the shingles is fastened improperly, it means the fasteners missed the framing so nothing is holding the plywood down and it could warp.

Another reason why sheathing boards can warp is if they were stored in a moist environment before being attached to your roof, or if the bare plywood was exposed to inclement weather and not shielded with plastic before the shingles were nailed down.

Leaving these framing and sheathing issues unfixed is mainly a cosmetic issue and shouldn't affect the integrity of your roof. 

“The only way to fix it is to redeck the house, which can be fairly expensive—coming in at about $1 to $1.50 per square foot,” says Ami Feller, Expert Review Board member and owner of Roofer Chicks in New Braunfels, Texas. “If you are getting a new roof and have noticed waves in your old roof, discuss it with your roofing contractor prior to installing a new roof.”

2. Damaged Felt Underlay

Typically when completing a roof repair or replacing old shingles, a roofer will not remove more shingles than they can replace in the same day. This is because when the felt underneath the shingles is exposed to wet weather or morning dew, it will cause the felt to wrinkle. It's important to note that you shouldn't ever install a roof in the rain.

The wrinkles will lay down flat if allowed to dry before first installing the shingles, but if the roofer stapled down the new shingles over wet felt, the new shingles will likely look wavy. Damaged felt underlay is mainly a cosmetic concern.

3. Expansion

If a roofer installs shingles when it is close to freezing outside (40 degrees or below) and doesn’t leave a gap, you may see a wave from expansion.

Unfortunately, the only solution to fix this problem is removing and replacing the shingles, otherwise it could shorten the lifespan of your roof. 

4. Poor Craftsmanship

If you notice ripples like on a pond, that can be caused by improper stapling or nailing direction. Felt should always be stapled (or you can use plastic cap nails) and shingles nailed down in the direction the shingles are being laid. If shingles are not nailed down properly, they can be blown off in strong winds or storms and that can cause leaky roof problems for you in the future.

Can I Ask the Contractor to Re-Do a Roofing Job If My Shingles Look Wavy?

If the roofing contractor doesn’t adhere to the contract you agreed upon prior to starting on the roof, there are a few things you can do. First, you can ask them to investigate what’s causing the wavy shingles and then repair the problem. Many contractors will re-do the work for free if they made a mistake and provided subpar work in order to keep their license and maintain their business’ reputation.

However, if the contractor won’t call you back or refuses to re-do the job, you can start with leaving a review to let other homeowners know about the experience. You may also need to gather as much related documentation as you can and consult an attorney to explore your legal options.

Hiring a New Pro

Before calling a pro you should learn about the roof replacement process to ensure you can ask all the right questions so the project goes smoothly. Make sure to look at reviews for local roofing companies near you to see what other homeowners thought of their quality and document everything in writing once you find the right company.

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