Sheet Pan Warping: Know Why and Prevent

Ever wondered why your sheet pans make a sudden “PONG!” sound in the oven? Fear not; it’s likely the metal warping as it expands and contracts during the heating process.

In this comprehensive guide, we’ll delve into the physics behind sheet pan warping, why it happens, whether it’s a cause for concern, and most importantly, how to prevent it.

Let’s ensure your sheet pans remain pristine and ready for culinary adventures.

Why Do Sheet Pans Warp?

The metal of your sheet pan, cooler than your hot oven, expands as it heats. However, the large surface area heats and expands faster than the shorter rimmed sides, creating stress at the base’s junction with the raised lip. This stress leads to some pans buckling or twisting, with thinner sheet pans more prone to warping than heavier counterparts.

Is It Bad for Sheet Pans to Warp?

The short answer is no. Sheet pans usually straighten out as they reach temperature, and a slightly warped pan performs just as well as a regular one.

The pop you hear is not forceful enough to cause damage or fling food onto oven walls.

Tips to Prevent Sheet Pan Warping

  1. Avoid Cold Pans in Hot Ovens:

Refrain from placing cold pans directly into a preheated oven. Instead, chill cookie dough on a plate before baking.

  1. Preheat Empty Sheet Pans:

Place an empty sheet pan in the oven as it preheats for extra crispiness. For cookies, preheat the pan briefly or run hot water over it to prevent excessive spreading.

  1. Use the Right-Sized Sheet Pan:

Ensure the sheet pan’s surface is evenly topped with food. Bare spots heat faster, causing temperature differences that may lead to warping.

  1. Avoid Overcrowding:

Provide adequate spacing for food to brown evenly. Crowding can lead to uneven heating and potential warping.

  1. Understand Oven Hot Spots:

Familiarize yourself with your oven’s hot and cool spots. Place pans where heat distribution is most even, often at the top and bottom center or on the sides.


Understanding sheet pan warping is the key to preventing it. By following these tips, you’ll maintain flat, reliable sheet pans for your culinary creations. Embrace the physics behind the “PONG!” and keep your kitchen adventures worry-free.