Get Answers to Your Shingle and Roofing Questions 

We're always available to assist you when choosing the proper Owens Corning shingles and roofing products for your project. Here we compile the questions that metro Atlanta homeowners and roofing contractors ask most often to give you a head start on your research. 

All too often, roof problems are discovered after leaking or other serious damage occurs. Periodic (twice a year) inspections can often uncover cracked, warped, or missing shingles, loose seams and deteriorated flashings, excessive surface granules accumulating in the gutters or downspouts, and other visible signs of roof problems. Indoors, look for cracked paint, discolored plasterboard, and peeling wallpaper as signs of damaged roof areas.

Sooner or later, every roof needs to be replaced, usually due to the long-term effects of weathering. If a residential roof is more than 20 years old, it is a prime candidate for replacement. Here are some signs that you need a new roof:

  • On the ground, walk around your home with binoculars and inspect your roof for cracked, curled or missing shingles, as well as any excessive loss of the protective mineral granules. DO NOT CLIMB ON THE ROOF; walking on the roof is dangerous and can damage your roof.
  • In your attic, take a flashlight and look at the underside of the roof deck and rafters for any stains or wet spots indicating water leaks.

Asphalt shingles can often be applied directly over existing roofs without tearing off the old roof. However, new shingles cannot be properly applied over hard or brittle materials, uneven surfaces for nailing or roof decks with warped, rotted or unsound support that should first be replaced or repaired.

Some local ordinances forbid re-roofing over two or more layers of shingles. If a home already has been shingled several times, it is important to first determine if the roof deck can support another layer of shingles before undertaking any re-roofing project.

You have two basic options. You can choose a complete replacement of the roof system, involving a tear-off of the old roof, or a re-cover of the existing roof, involving only the installation of a new membrane and surfacing. If you've already had one re-cover, check with a professional roofing contractor to see if your deck can support a second re-cover.

Product Performance. Asphalt shingles perform well in extreme temperatures and in areas where wind, water, and ice are prevalent.

Affordability. The efficient, high-volume production and relatively low application cost of asphalt shingles provide consumers with an overall value that’s difficult for other roofing materials to match, especially in terms of comparable life expectancy.

Low Maintenance. Asphalt shingles, when properly chosen and applied, require little or no regular upkeep, and are easily repaired if damaged.

Ease of Application. Asphalt shingles are considered to be the easiest of all standard roofing materials to apply. In addition, the flexibility and strength of asphalt shingles support their application on a wide variety of roof designs.

Fire and Wind Resistance. Asphalt shingles are manufactured to resist external fire and flammability standards, and carry Class A, B or C fire ratings, with Class A providing the greatest fire resistance. These fire ratings are defined by nationally recognized standards and tested by independent testing agencies. In addition, many asphalt shingles carrying a "wind resistance" label indicate that they have been manufactured and tested to demonstrate acceptable resistance in high-wind locations.

Architectural Shingles: (See Laminated Shingles)

Asphalt: A bituminous waterproofing agent applied to roofing materials during manufacture.

Deck: The structural surface to which the roofing or waterproofing system (including insulation) is applied.

Flashing: Pieces of metal or roll roofing used to prevent water seepage into a building around any intersection or projection in a roof, such as vent pipes, chimneys, adjoining walls, dormers and valleys.

Granules: Ceramic-coated colored crushed rock that is applied to the exposed surface of asphalt roofing products.

Hip: The inclined external angle formed by the intersection of two sloping roof planes. Runs from the ridge to the eaves.

Incline: The slope of a roof expressed either in percent or in the number of vertical units of rise per horizontal unit of run. Also referred to as slope.

Laminated Shingles: These shingles have more than one layer of tabs to create extra thickness. They are often referred to as three-dimensional or architectural shingles because they create visual depth on a roof and impart a custom look.

Membrane: A roof covering or waterproofing layer whose primary function is to repel water.

Pitch: The degree of roof incline or slope expressed as the ratio of the rise, in feet, to the span, in feet.

Re-covering: The process of covering an existing roofing system with a new roofing system.

Re-roofing: The practice of removing an existing roofing system and replacing it with a new roofing system.

Ridge: The uppermost, horizontal external angle formed by the intersection of two sloping roof planes.

Roll Roofing: Asphalt roofing products manufactured in roll form, either smooth- or mineral-surfaced.

Saturated Felt: An asphalt-impregnated felt used as an underlayment between the deck and the roofing material.

Self-Adhered Eave and Flashing Membrane: A self-adhering, waterproofing shingle underlayment designed to protect against water infiltration due to ice dams or wind-driven rain.

Strip Shingles: Manufactured in both standard and metric dimensions, these asphalt shingles are approximately three times as long as they are wide, and are distinguished by their number of cutouts or tabs. The most common are three-tab.

Square: A unit of roof measure covering 100 square feet.

Three-Dimensional Shingles: (See Laminated Shingles)

Underlayment: Asphalt-saturated felt used beneath roofing to provide additional protection for the deck.

Valley: The internal angle formed by the intersection of two sloping roof planes.

Vapor Retarder: A material designed to impede the passage of water vapor into the roofing system.

3-tab Strip shingle: These are the most common type of shingles on the market. They have a very flat appearance and are what most people picture when they think of the word "shingle." They are available in two basic categories: 20-year and 25-year, with the 25-year shingle being available with Fungus Resistance to keep the black streaks off of the shingles.

Dimensional or Architectural (Laminated) shingle: If appearance is an influential factor in addition to function, these value-added shingles have a number of different looks and color blends to give the roof a "layered" look. These laminated shingles weigh more and are stronger than economy shingles and, as a result, offer a greater degree of wind, tear and blow-off resistance in addition to greater value and longer warranties. All are available with Fungus Resistance to keep the black streaks off of the shingles.

Not necessarily. Leaking can result because some flashings have come loose or because a section of the roof has been damaged. A roof failure, however, is generally irreversible and results from improper installation or choice of materials, or from the installation of a roof system inappropriate to the building.

The short answer is "Yes," but there are several reasons:

  • Good ventilation creates a cooler attic in the summer
  • An overheated attic, combined with moisture, can be damaging to roof decking and roofing shingles, causing them to distort and deteriorate prematurely
  • Good ventilation creates a drier attic in the winter and helps prevent ice dams

Good ventilation serves two main functions:

  1. Moves hot air next to the roof deck out of the attic in the summer
  2. Dilutes and removes the moist air in the winter before it can cause damage
Waterproofing underlayment is installed underneath the shingles in areas where extra protection is needed. High-wear areas like the valleys on the roof, around dormers, rakes, eaves and skylights are good places to put an extra barrier of protection against water leakage caused by ice damming and wind-driven rain. Waterproofing underlayment is self-sealing so that it seals around nails providing a water-tight barrier against moisture.
The price of a new roof varies widely, depending on the material selected, the contractor doing the work, the home itself, area of the country, local labor rates, time of year, and more. To get a good idea of the cost for your roof, get several estimates from reputable contractors in your area. Keep in mind that cost is only one factor, and it must be balanced against the quality of the materials and workmanship. For each roofing material, there are different grades and corresponding prices. Plus, there are a variety of styles and shapes. You need to look at the full product range and make a choice based on your budget and needs. There are different levels of expertise and craftsmanship within the roofing profession. Pick a contractor who is committed to quality work.
The condition and lifespan of your roof depends on the type of roof you have, the effects of your local environment and the maintenance the roof has received. According to the American Society of Home Inspectors, asphalt shingles generally last 15-50 years; wood shingle/shakes, 10-40 years; clay/concrete tiles, 20+ years; slate, 30-100 years; metal roofing, 15-40+ years. Roofing product manufacturers offer a variety of warranties on their products. Take a close look at those warranties to see what responsibilities and financial obligations they will assume if their products fail to reach their expected lifetimes.
Most work should not be do-it-yourself. Professional roofing contractors are trained to safely and efficiently repair or replace a roof. Novices can harm a roof with improper roofing techniques and severely injure themselves by falling off or even through a roof in need of repair or replacement. Homeowner maintenance should be confined to roof inspections in both the fall and spring to check for cracked or curling shingles, and to cleaning rain gutters filled with dead leaves and other debris. If you must see the roof for yourself, use a firmly braced or tied-off ladder equipped with rubber safety feet. Wear rubber-soled shoes and stay on the ladder (and off the roof) if possible.
If you've had hail in your area, a close inspection needs to be made at roof-level to determine if the shingles have been damaged. Usually you cannot tell from the ground.

Call your insurance company and ask for an adjuster to inspect your roof for hail damage. Call a reputable roofing company and ask for the same inspection. If there are any discrepancies between the adjuster's findings and the roofer's findings, you may call for a re-inspection where your adjuster meets with the roofer to go over the roof together. Re-inspections are very common. The insurance company must determine two things when assessing the amount of your loss:

  1. Was there sufficient damage to the roof to declare it a total loss? (Usually determined by 10 to 14 verified hail hits per 100 square feet.)
  2. What is the size of the roof and how many shingles will be needed to replace the roof?

Shingles are designed so that the granules block the UV of the sun and protect the asphalt underlayment. As the shingles age, the granules fall off. As the asphalt is exposed to the UV, it dries out and the shingle gets a "potato chip" appearance as the corners start to curl up. A shingle at the extreme end of its life is bubbled in appearance and brittle to the touch. A 20-year shingle is warranted by the manufacturer to have a useful life, under optimal ventilation conditions, of 20 years. Hail does several things:

  1. Accelerates granule loss
  2. Accelerates shingle aging
  3. Voids manufacturer’s warranties
  4. Leads to additional associated problems 
The insidious nature of hail damage is such that it may pose no immediate threat to the structural integrity of the roof. However, many insurance companies have a "statute of limitations" on how long a hail claim is viable. If you have experienced a loss such as hail damage, it is prudent to rectify the problem in a timely manner before it leads to other associated problems.
A hail hit on a shingle looks like a "bruise" or a dark spot where the granules on the shingle have been knocked off and the asphalt underlayment, and sometimes the fiberglass mat, is exposed. New hail hits have a shiny appearance because the asphalt has been freshly exposed and has not had time to weather to a dull color.

The purpose of homeowners’ insurance is to protect homeowners against losses in their property's value due to damage that is beyond their control. If you have hail damage, you have experienced a financial loss in that your original investment of a 20-year roof, for example, has now been reduced to a 5-10 year useful life span. Your insurance company will compensate you for your loss and replace your roof.