Composition roofing or “shingle roofing” is the most commonly used form of roofing materials on the market. If you take a look around any neighborhood in America you’ll primarily see composition roofs. This is due to the low cost of materials and the widespread availability of materials.
Composition shingles consist of a fiberglass mat which is soaked in asphalt and filled with mineral fillers. Basically, the fillers stick to the fiberglass and the asphalt surrounds the formation, making it waterproof.
There are positives and negatives to composition roofing, but first lets look at the different types of shingles. There are 4 main categories of composition shingles with a variety of colors to choose from.
3-Tab Shingles – Least Expensive – 25 Year Warranty
The lowest grade of shingle is the “3-tab” shingle. It has a three evenly spaced tabs, giving the shingle an even or flat appearance. While it used to carry a 20 year warranty, most shingle manufacturers have changed the 3-tab warranty to 25 years. This type of shingle is the thinnest shingle on the market and therefore is the most easily damaged by hail.
Dimensional or Laminate Shingles – 30 Year Warranty
The 30 year roof, also referred to as a “dimensional” or “laminate” shingle, has two layers of shingle material bonded together, which makes it thicker than the 3-tab shingle. This extra thickness provides added durability during hailstorms. Compared to the flat look of the 3-tab shingle, many homeowners prefer the look of the dimensional shingle Due to the upgraded look, most homeowners choose to upgrade to a laminate shingle when they replace their roof.
Designer Shingles – Most Expensive – 30+ Year Warranty
Premium shingles can be up to twice as thick as the 3-tab shingle, increasing their wind resistance, hail resistance and overall lifespan. There are many different styles for this type of shingle including slate and wood shake. The primary added cost of these shingles is material cost
Class 4 Shingles – UL 2218 Rated
Class 4 shingles are the highest rated hail resistant shingles. Because of this rating, a class 4 roof will qualify you for a discount on your insurance premiums. GAF, the nations largest shingle manufacturer, only carries 3 types of Class 4 shingles. The shingles have Class 4 rated ridge caps to accompany the shingles. The decision to choose a Class 4 shingle should be weighed between the cost to upgrade to Class 4 and the premium discount from your insurance company.
What are the positives of composition shingles?
- Least expensive. Composition roofs are much less expensive than metal roofs. Although the benefits of metal roofs clearly outweigh the benefits of composition roofs, you cannot beat the short-term costs of a shingle roof.
- Decent Lifespan. 30 years is a long time for a roof to last. In the Texas heat, the roof is still going to last 20 years or more. Since we live in Texas and the odds of a hailstorm in 20 years are very good, your insurance company will most likely pay for your roof before you have to.
- Easily Repaired. Shingle roofs are fairly easy to install because of the ability to install from the left or the right. Unlike metal roofs that have interlocking pieces or overlapped panels, shingle roofs are easily repaired.
What are the downsides to composition shingles?
- Algae. One downside to fiberglass shingles is they have a tendency to attract algae, making them not only look dirty, but the formed algae build-up can cause the shingles to lose some of their heat-resisting properties.
- Granule Loss. Due to the expansion and contraction of the shingles throughout the years, the granules can fall off leaving the exposed fiberglass mat.
- Blistering. Blistering looks like hail damage, but insurance companies do not cover blistering. Excess heat causes the granules to fall off of the shingles and the exposed fiberglass mat starts to deteriorate.
- Insurance Endorsements. Insurance companies are adding endorsements to policies, forcing homeowners to pay for their roofs out of pocket. See Actual Cash Value after 15 years of age.
What are the components of a composition roof?
- Underlayment. Synthetic felt is used on all of our roofing installations. The waterproofing qualities of synthetic underlayment are much better than typical 15 lb. felt.
- Drip Edge. Drip Edge is a trim piece installed on the perimeter of the roof to allow water to drain and drip off. This prevents water from soaking the fascia wood and causing long-term wood rot.
- Pro-Start. Pro-Start is installed along the roof perimeter underneath the first shingle. The adhesive on the shingle helps all of the shingles on the edges to stick to the roof. This provides better wind resistance.
- Ice & Water Shield. Ice & Water shield is like an underlayment on steroids. You can put a nail into it and it will self-heal to prevent leaks. It is used down the valleys and around holes in the roof, such as pipes or vents.
- Valley Metal. Valley metal is installed down the valleys as a shield to prevent water from leaking in the valley areas.
- Ridge Caps. There are 3 main types of ridge caps used to accent the roof shingles. Most commonly used are cut-up 25 year shingles. The high-profile ridge caps for GAF are called Z-Ridge and the Class 4 Ridge Caps are UL-2218.
- Ventilation. Read on to learn about ventilation.
Visit GAF’s lifetime roofing system to see a detailed description of the proper roofing components.
What are the different types of roof ventilation?
Passive Ventilation and Active Ventilation are the two types of attic ventilation.
- Passive Ventilation depends on air flowing up through the soffit vents and out these exhaust vents.
- Turbines, also known as whirlybirds, look like circular spinning vents. These vents work well, but the steel can rust over time and wear and tear causes them to stop spinning.
- Ridge Vent requires a 2″ gap cut in the decking along the ridge and a 13″ plastic ridge vent is placed over the gap. This allows air to escape through the very top of the roof. Ridge cap shingles are installed on top of the ridge vent to cover up the plastic look.
- Box Vents, also known as turtle vents or slant backs, look like little boxes on the roof.
- Active Ventilation physically pulls the air out of the attic using a powered vent.
- Power Attic Vents can be electric or solar powered. The electrical power attic vent is installed with a switch to turn the vent on and off. The solar powered vents have a regulator installed which only turns the vent on if the attic reaches a certain temperature. The on/off switch depends on the temperature and is used to avoid pulling out the hot air in the winter or pulling out the cooler air in the summer.
Composition Roofing – Overall Thoughts
Composition roofing is a very good roofing choice. It provides a decent lifespan with an economical cost. When the roof is hail damaged, your insurance company will pay to have it replaced. If you are looking for something longer lasting with better energy benefits, then metal roofing is way to go. There are a variety of options to choose from to give you the look you desire.