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Roofing 101

When most people think of a roof, they think of shingles. While shingles are the most visible part of your roof, they alone do not make up a roof!
Your roof is a system made up of several components and layers designed to work in tandem to provide the necessary protection for your home and your family. Replacing only one element of the system is bound to cause premature wear while reducing durability and longevity. To better understand your roof as a system, we've outlined the components below.
roof deck - roof sheathing - roof plywood

Roof Deck

The roof deck (plywood) is the foundation of the roof’s structure and where all roofing materials are adhered. Most roof decks are made of OSB plywood that range between 3/8" and 1/2" sheets, but some homes may have a deck made of roof board (thick and coated plywood). The roof deck MUST be inspected BEFORE any new materials are installed. If you don’t inspect the deck, chances are you’ll run into costly issues down the line even with newly installed shingles. 

ice and water shield - roof underlayment

Ice & Water Shield 

Ice & water shield is a modified bitumen membrane designed to protect the lower edge of the roof from ice and snow that can backup under the shingles. Ice & water shield is to be installed a minimum of 3-feet up from your eavestroughs, in all valleys,  and around any protrusions, such as a skylight or chimney. 

roof underlayment - synthetic underlayment - proper roofing - new roof


After the ice & water shield, the remainder of the roof should be wrapped in a synthetic underlayment. This wrap is designed to protect the roof deck, offer a secondary barrier against water penetration, and helps the shingles adhere better to the roof before being nailed in. Most shingle manufactures require underlayment to be installed beneath their product in order to ensure a valid warranty. If no synthetic underlayment is installed, you will have little to no protection in the event of a product defect.

starter shingles - shingles - proper roofing

Starter Shingles

Starter shingles are the initial shingle products installed on a roof along all the edges. While often hidden from view, they aid in the roof’s water-shedding function by covering shingle joints at the eaves and greatly improve the roof’s wind resistance by sealing the finished shingles to the roof at the eaves and rakes. They also provide the installer with a clean line to use as a guide when installing the main shingles. 

roof shingles - new roof shingles - good roof shingles


Shingles are designed to shed water away from the roof while protecting your home against the elements. Fiberglass laminated shingles are the norm nowadays. These architectural-style shingles are asphalt-based but are thicker than traditional 3-tab shingles and coated with a fiberglass laminate, thereby offering significantly greater life and durability. A proper installation with all the required components will provide decades of reliability.

metal drip edge - protect your roof - proper new roof installation

Drip Edge

Drip edge are pieces of metal installed around the perimeter of the roof above the eaves. Their purpose is two-fold - to guide water directly into the eavestroughs, and to protect the fascia board from water penetration. They are designed with a dual lip, whereby one end sits underneath the first row of shingles and is secured to the roof, and the other end overhangs the opening of the eavestroughs and creates a clear path for water to flow down into the gutters. 

metal roof valleys - valleys on a roof - new valleys


Valleys are present where two planes of a roof intersect. There are two types of valley systems – closed and open. Closed valleys are where the shingles are cut to form the “V” of the valley, whereas open valleys have a piece of sheet metal lining the valley with the shingles butting up against it. Open valleys are much better systems because all the water/ice/snow will rest directly on the piece of sheet metal instead of the shingles, thereby extending the life of the roof. 

roof flashing - metal flashing - wall flashing for a roof


Flashings are strips of metal that are installed wherever a roof line meets a wall and around chimneys. Aside from complementing the esthetic appeal of a new roof, flashings are designed to provide protection against driving rains and water penetration into the home. While it's not mandatory to replace the flashings when replacing the roof, a new application of caulking should be applied to the seams when keeping the existing metal. 

metal roof vents - proper roof ventilation - correct roof vents


Ventilation is the most important component of any roofing system, as it ensures you get the most life possible out of your roof. Improper venting or re-using old vents are major contributors to a shortened roof life, leaks, shingle degradation, condensation buildup, popped nails, blown-off shingles, and other costly repairs. Proper placement of roof vents, an adequate number of them, and the correct type of vent are all crucial to the life span and functionality of the roof. 

soffit and fascia - roofing

Soffit & Fascia

Soffits are the aluminum panels on the underside of the roof line. Vented soffits are part of the overall ventilation system and designed to draw fresh, cool, outside air into the attic so the roof can breathe. It’s imperative that you have an adequate number of vented soffit panels surrounding your home, and that there are no blockages of these panels in the attic that would prevent air from entering the space. 

Fascia is commonly referred to two components – the fascia board (the front-facing wood structure directly beneath the roof line), which offers structural protection for the home, and the fascia trim, which is the aluminum cladding that covers the fascia board and protects the wood. 

eavestroughs - gutters - roofing


Eavestroughs (or gutters) collect water run-off from the roof and direct it away through the downspouts. It’s critical that your eavestroughs are functioning properly because a poorly performing gutter system will result in a multitude of costly issues. A properly functioning eaves system includes a correct slope, clean gutters, suitably sized downspouts (and an adequate number of them), and no dents, sagging, drooping or pulling away from the fascia.  

Rovis Roofing assesses and installs all the components of a roofing system. 
Contact us today for any roofing inquiries or service requests!

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