Roof Anatomy: What’s Underneath the Shingles

The surface of the roof, the one visible from the curb, is just one part of your home’s entire roofing system. In truth, your home is more complex and not just a simple layering of shingles. Knowing the different parts of the roof is important as it will help you understand roof replacement and better repair practices.

Roof Anatomy: What’s Underneath the Shingles

Pro Exteriors discusses the parts of the roof underneath the shingles:


Also known as the wood sheathing, this is the base on which everything else is laid on. It’s essentially the foundation of the roof. This is typically made with OSB or oriented strand board or plywood that’s attached with nails onto the rafters. Since it’s made of wood, it will require general roof repair if there’s a leak or water intrusion coming from the shingles.


This durable paper is saturated with asphalt and installed on top of the decking, right underneath the shingles, hence its name. It serves as the roof’s last line of defense when water leaks from the shingles occur due to cracking or tearing.

Drip Edge

Also known as eave flashings, these angled aluminum strops are nailed over sides of the underlayment at the edges. They prevent water from building up at the sides and redirect them to the eaves and, eventually, to the gutters.


These are the thin metal strips located at the most vulnerable parts of the roof, such as the hips and valleys. They essentially act as a barrier to prevent water leakage and pooling on the surface. Although they extend the life of the roof, they are susceptible to wear and tear, too. As such, it’s important to regularly check if the flashings on your roof are still in good condition.

Pro Exteriors is a local roofing company that offers complete roofing services. Call us today at (302) 664-1700 to learn more about how we can help you keep your roof in good condition. We offer roof repair in Easton, MD and surrounding areas.

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