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Anatomy Of A Shingle Roof

Installing a new roof or having one replaced can be complicated for a number of reasons. What kind of shingles do I want? What benefits do I need for my home? And how do I communicate this with my roofer once I find out?

The anatomy of a roofing system is similar to the anatomy of our own bodies. Shingles function as the skin of our roofs, keeping out water and the elements. Below that, there are layers with different functions and benefits. Understanding each component of shingle roofs will relieve stress on your end and help you better communicate your desires and ideas with your roofer.

Let's begin with the parts that make up shingle roofs.

1. Roof Deck

The decking of your roof bears the weight of all roofing parts and gives your roof its structure. You'll see roof decking on houses that are mostly bare. Sheets of plywood generally serve as roof decking, matching the rest of the house. At this point, without any other layers, your roof would quickly succumb to weather and UV rays. Think of the decking as the bones of your roof, there to support and brace.

2. Underlayment

The underlayment layer acts as a waterproofing seal. It protects your attic from water damage and extends the life of your roof considerably. Underlayment is made from thick felt or other synthetic materials, creating that water-tight barrier and giving shingles something to attach to. There are a few variants of underlaying, differing in material and thickness. Your climate will often dictate what type of underlayment is best for you, which your roofer will help advise on.

3. Flashing

Flashing is placed around chimneys and joints. Its primary purpose is to prevent water seepage in joint areas of your roof and add some extra durability and life. Flashing is made out of metal. Roofers screw it into place around any seams or protruding vents. You may see flashing around chimneys, but otherwise, it's an invisible component.

4. Drip Edge

Drip edges work like flashing, but with water movement in mind. Drip edges run along the edges of your roof, encouraging water to run down and off rather than sticking around and causing mold or rot. They are especially important during rainy seasons and for dealing with snowy slush.

5. Shingles

Shingles make up the final layer of roofs. They are the primary shield against wind, rain, UV rays, and even fire. Asphalt shingles are the most common roofing material due to their low price and durability. They are made from a variety of materials, with some asphalt mixtures being a bit stronger than others. Depending on where you live you may want to choose fire-resistant shingles or ones designed to be extra wind-resistant.

Standard shingles will cover the flat slopes of your roof. They can come in sets of three, making up a larger sheet, or in individual squares. For hips and ridges, your roofer will use shingles designated for that purpose. Hip or ridge shingles cover the top ridge of your roof and all other connecting seams, creating a water-tight cover over areas more prone to water leaks.

Structural Roofing Components

Now we can move on to the structural parts of your roof. The build of each roof is close to unique, depending on your neighborhood and personal preference. There are several designated roof styles in the roofing world, like gable roofs or mansard roofs. Each style is made of the same components, just in different amounts and sizes.

1. Ridges

The ridge of a roof is the connecting seam on the very top. It's the highest point of your roof--everything else slopes down from this point. Ridges also run down slopes with connecting seams, overlayed with hip shingles to keep water out.

2. Vents

Vents allow moist, hot air to escape from your attic. Without roof vents, you'd have a tropical environment in the top half of your home. These vents are normally placed along ridges or on gables. Pipes are sometimes used to vent humid air, too.

3. Dormer

Dormers are squared sections that rise from a slope in your roof. They usually create space for bedrooms and allow windows to be put in place. Other times, they create an aesthetic appeal and allow natural light into attics.