Your roof is more than just shingles. It is a complex system. So, what makes up the components of a roof?

Roof Deck: This is your base layer and supports the whole roof system.

Drip Edge: This is most often metal and lays on the Roof Deck. The Drip Edge extends beyond your base layer and allows water to drip into gutters and off of the roof. It also prevents wind from getting underneath the shingles.

Ice and Water Shield: The Shield is self-adhesive and attaches directly to the drip edge and decking. While water could potentially get through your shingles, the Shield prevents it from getting to your roof deck.

Underlayment: The Underlayment is an extra layer of protection against severe weather. Allstate Roofing and More, LLC manufactures and uses Dry-Deck, a breathable, water resistant underlay—which comes with a 50-year limited warranty!

Shingles: There are typically two layers of shingles—the starter layer which has a tar strip on the top of the shingle, and the top layer which has a tar strip on the bottom of the shingle. The tar strips adhere to each other for a double seal, which helps prevent wind from getting under and impacting the shingles.

Venting: Without proper venting, your whole roof system will collapse. Roofs each have a soffit vent which is an “intake” vent at the bottom of the roof, and a ridge vent at the top of the roof. This system allows hot air to go out the ridge vent, and cool air to come in through the soffit vent. Without good venting, in the summer shingles can scorch and glue can actually melt on the roof! In the winter, it could impact the heating bill at your home, and in the rainy season, lack of good ventilation can cause mold.

Now that you are familiar with the components of a roof, it’s important to know how they are different than a roof layer. When someone asks how many layers you have on your roof they are typically referring to layers of shingles, not all of the components discussed above.

Did you know that on old cedar homes, there are typically three layers of shingles—original cedar, and two layers of asphalt shingles? In some cases, there can be even more! This sometimes happens when home owners get a metal roof installed on top of the layers that they already have. Having more than three layers of roofing, however, is against code in most towns!

See Jim Lorentz, Allstate Roofing and More, LLC’s Production Manager, talk in depth to 13 WHAM’s Ashley Doerzbacher about each of a roof’s components.  To learn more, or for a free estimate, contact us at 585-400-7663 or