When you think of a roof, you probably picture shingles. But those shingles need a solid surface to nail into—and that surface is the Roof Decking (also called "sheathing"). Think of it as the "floor" of your roof that sits on top of your rafters.

What is Roof Decking?

Decking is the structural foundation of your roof. It typically consists of large sheets of wood—usually OSB (Oriented Strand Board) or Plywood—that cover the entire surface area of your home. It provides the strength needed to hold the weight of the shingles and any snow load during an Illinois winter.

When Does Decking Become a Problem?

In a perfect world, decking lasts through multiple roof replacements. However, because it is made of wood, its biggest enemy is moisture. You might need decking replacement if:

  • Rot & Soft Spots: If water gets under your shingles (or if your attic has poor ventilation), the wood will rot.

  • Sagging: If you look at your roofline from the street and see "dips" or "waves," it’s often a sign that the decking has lost its structural integrity.

  • Delamination: Over time, the layers of plywood can pull apart, meaning nails won’t hold securely anymore.

The "Tear-Off" Surprise

The biggest challenge with decking is that we often can't see the full extent of the damage until we "tear off" your old shingles. This is why professional contractors include a "decking price per sheet" in their estimates. At Stan's Roofing & Siding, we always perform a thorough inspection of the wood once the old roof is removed to ensure your new shingles are being nailed into a rock-solid foundation.