Understanding Your Roof: A Roofing Terminology Guide

Friday, June 29th, 2018 by Sydney Stewart

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Though our project managers do their best to provide a comprehensive explanation of your roofing system, without any prior knowledge it may be a lot to take in and process. At My-Pros, we want to ensure that you understand the roofing system. We have created a small encyclopedia of common roofing terms that you may not be familiar with.

Ice & Water Shield – This is a roofing material made with a rubberized asphalt mixture. It is generally installed along the lower edge of the roof, especially if it is steep. It helps to protect water that flows backwards up the roof. The most traditional type of ice and water is peel ‘n stick. Because of the sticky backing, it adheres directly to the wood of the roof and doesn’t have space for water to penetrate when overlapping the product.

Underlayment – My-Pros only used synthetic underlayment on our roofs. Synthetic underlayment is different than the traditional felt paper that was popular a couple of decades ago. This underlayment is a barrier between your shingles and the wood on your roof. It is the true protection for your home. It prevents water from leaking underneath the shingles and into your home. This should always be applied directly to the decking after all the existing shingles have been removed.

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Synthetic Underlayment with Ice and Water Shield on The Edges


Decking – The roof deck is the material between the structure of the roof and the insulation of the roof. On residential roofs, this is commonly made of plywood or tongue and groove wood systems. This material needs to be strong enough to hold the weight of your entire roofing system. Sometimes with improper shingle installation and leaks, the decking may need to be replaced on a home if it has rotted.


Flashing – In areas of your roof that are prone to leaks and water damage, such as around the chimney or where a roof meets a dormer, flashing should be installed. Flashing is usually made from a rust-resistant metal such as galvanized steel, aluminum, or copper. This flashing helps standing water stay on the roof versus soaking into your home and causing damage. Chimney flashing is applied around the base of the chimney and up the sides. Flashing should always be installed around skylights, which should come with the product for a correct fit.

3-tab Shingles vs. Architectural (3D) Shingles – 3-tab shingles have only 1 shingle tab size and shape. They are one flat layer that does not have any dimension, this means they weigh less than architectural shingles. They are thinner and have a shorter life than architectural shingles. Therefore My-Pros only installs Architectural Shingles on our homes. These shingles have a more dimensional look and weigh approximately 50% more than the 3-tab shingles. They raise the value of a home and have a minimum 30-year guarantee across the board.

Ridge Cap – Every sloped roof will have a point where the different sides meet. This area is called the ridge. Special shingles, called ridge cap shingles, need to be installed in this area. These are used to provide a complete water shedding system starting where rain first meets your roof. These shingles can also hide ridge cap ventilation from your attic.

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3-Tab Shingles vs. Architectural Shingles with a Ridge Cap

Starter – These shingles are a key component to a new roofing system. These are used to waterproof the eave and rake edges of your home. These give roof a nice straight line on the edge as well as help prevent blow offs. The top half of the starter shingle catches any water that flows into the seams between shingles and directs it down and off the home instead of creating a leak.

Soffit – Soffit is the exposed overhang of your roof. It generally matches your siding or exterior and is primarily white. It can be made from a variety of materials including wood, aluminum, or vinyl. Since My-Pros is in the Midwest, we recommend vinyl soffit to protect your home from the elements. Soffit creates a steady airflow between your roof and attic, which prevents mold from forming.

Fascia – Fascia is the small area of siding directly above the soffit. This is generally made from the same material your soffit is made from. Fascia is the final support for the shingles and decking on your roof. This is the component of your roof that gutters are installed on and it’s important that they are strong enough to hold the water collected by your gutters during a storm.

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Soffit and Fascia on a Garage Roof

Eaves & Valleys – An eave is the lowest horizontal plane on the roof. This is a very vulnerable part of the roof where extra protection is built in. A valley is the low point between two sloping roofs. This is also a vulnerable part of your roof is it is not properly pitched for water to flow down.

Gutter Apron – This is installed on the edge of a roof at the eaves. It hangs into the gutter and its primary purpose is to direct water from the roof into the gutters. It comes in many colors that match your gutter choice.

Drip Edge – Drip edge is the metal flashing located at the edge of a roof. It is installed with a tilt so that the water is directed away from the roof. This should be installed between the sheathing board and the fascia on top of the roof’s exterior cover. Apart from protecting your roof from water, it also helps to deter pests and critters from entering your attic. 

My-Pros operates throughout the Northern Illinois and Southern Wisconsin region, in cities like Rockford, Machesney Park, Belvidere, and Beloit. Give us a call at 1-815-957-0770 or click here to schedule a free estimate!

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1107 N Blackhawk Blvd Unit 6
Rockton, IL 61072