A Guide To Shingle Materials
A roof would not be complete without its integral pieces, which are the shingles. Without shingles, we would have nothing but flimsy particleboard shelters defending our homes from the elements. As a form of engineering that took thousands of years to cultivate, modern roofs offer diverse shingles made from various materials. Each material has its advantages and disadvantages. It’s a good idea for you to become educated on them before purchasing a replacement roof for your home.
Shingle Material Lifespans
Other than protection, the primary focus consumers have toward roof materials is the longevity it provides. Large-sum investments, such as building a roof, are meant to build structures that endure and provide value. The ancients thought of this when they created systems with shingles that still exist today, and modern homeowners should feel the same.
3-Tab Asphalt Shingles
Asphalt shingles are the bread and butter of modern homes. As the cheapest shingle material out there, asphalt roofs provide an estimated lifespan of 30 years. Asphalt tiles are composed of asphalt, limestone, and ceramic granules rolled over a strip of fibres. For added fire protection, the base sheet is typically made of fibreglass. These asphalt tabs usually come in the ‘3-tab’ style but are also offered as architectural shingles for higher durability and longevity.
While they do not last a lifetime, asphalt shingles provide great structural defence for its low-cost. Specifically, asphalt roofs boast class B fire resistance with adequate physical defences, are waterproof if sealed, and even reflect UV light with their embedded ceramic granules.
Ceramic tiles, also known as clay tiles, are traditionally found in Mediterranean climates. They are known for their fluted, semi-circular appearance and earthy colouration. They are chosen for that specific climate because of their natural resistance to salt-water and heat. Additionally, clay tiles are incredibly long-lasting, with a lifespan of about 100 years. Their innate invulnerability to fire, insects, and mould growth is what makes this durability possible.
These tiles are not just suited for Mediterranean climates and styles, however. Clay tiles come in a variety of designs and shapes. Historically used throughout Europe, there are specific French, German, and English versions of clay tiles.
Like clay tiles, slate shingles are made from pieces of natural material. While the idea of using rocks as flat shingles may seem bizarre, slate has a natural tendency to break apart into smooth sheets. Further, many historic buildings feature slate tiles and have been around for almost 700 years. With that being said, slate roofs have one of the highest life expectancies, often estimated to be over 100- 200 years.
Another contributor to slate tiles longevity is attributed to its sturdiness as a rock. Like clay tiles, slate is resistant to algae and fungal growth, fire-resistant, and water repellant. Out of all of the other shingle materials, slate also brings with it a sleekness like no other.
Metal roofs are another popular, long-lasting roofing option. With an average life expectancy of 80 years, metal is a lasting, durable material to use. In terms of resistance, metal roofs have a Class A fire safety rating, will not crack, and naturally repels water with its sleek surface. Additionally, metal roofs have a reflective surface, making them energy efficient as well.
Typical steel roof styles are known as ‘sheet metal roofs,’ which is one long, fluted metal panel. However, steel shingles can mimic types like shake, slate, ceramic, and asphalt tabs. With metal roofs, you do not need to compromise on style in exchange for function.
There are different kinds of metal used as roofing materials for specific reasons, though metal roofs are commonly made from galvanized steel.
More than just an element of the periodic table, zinc is a popular metal of choice due to its ability to form a ‘patina.’ This patina protects the roof from natural elements, while also providing a strange regenerative capacity. When steel is scratched, the exposed area is left to rust. Zinc produces the fine patina, which reforms scratch marks. Like regular metal roofs, zinc roofs can last for 100 years.
Copper has been a metal roof option since the Romans’ time and is still accessible to this day. Copper is resistant to the elements, mould, fire, and corrosion, requiring no extra maintenance. Along with its natural, warm beauty, copper can last well over 200 years with the ability to be recycled. Depending on taste, the characteristic green patina that forms can be reversed or accelerated. There is a reason why the pantheon, statue of liberty, and Canadian parliament use copper roofs.
Aluminum roofs are known for their active resistance to salt-water, so they are ideal for waterfront homes. Besides this, aluminum also resists rusting, corrosion, and comes with the longevity of other steel roofs. For these reasons, aluminum is used in collaboration with steel to create ‘weathering steel.’
Wood shakes are shingles made from cut timber and are known for their rugged and uneven appearance. They are thicker than regular wood shingles and have slightly better water and wind resistance if treated and installed correctly. The type of wood included is red cedar, or pine, depending on your part of the world.
While being an attractive roof option with decorative applications, shake roofs are estimated to last only 30 years. Additional maintenance is required to reach or extend this, including multiple wood treatments to prevent fire damage, warping, and rot.
Energy Efficiency of Shingle Materials
Shingles are not only meant for protecting your roof. Some also perform the duty of increasing energy efficiency for the rest of your home. Since shingles are regularly exposed to UV rays, their ability to absorb or reflect UV light considerably reflects the price on your utility bill. This ability has a scientific term called ‘albedo,’ defined by an object’s ability to reflect or absorb light.
Generally speaking, materials with lighter colours like white are the most reflective. These materials have a high albedo and retain a cold surface when exposed to direct sunlight. On the contrary, dark surfaces that are black absorb UV energy and become two times as hot.
In most circumstances, roofs with higher albedo are preferred since they prevent heat from seeping into your home. Extra warmth and humidity added to a home can increase air conditioner use and even accelerate mould growth problems. In cases where the surrounding environment is cold and dark most of the time, black roofs are a bonus. This is because the low-albedo roofs will absorb heat and provide extra comfort in a cold environment.
The following shingle materials are considered to be the most energy-efficient:
Asphalt shingles are placed last because they are typically darker in colour despite their ability to reflect some UV light with their embedded granules. Thus asphalt shingles will always have a more challenging time competing in terms of albedo.
How Ventilation Affects Energy Efficiency
Going hand-in-hand with albedo is ventilation, another intelligent technology used to facilitate airflow and prevent the build-up of hot air. By itself, a roof and a house with no ventilation is just a box. Continual exposure to heat will cause the top to heat up, which in turn transfers heat inward. The trapped hot air dwelling in attic spaces will magnify the house’s temperature with nowhere to escape. This is not good.
The addition of roof vents allows all of that trapped air to be pushed out. Consequently, flowing air removes built-up heat, meaning less need to run the air conditioner. Just like water, stagnant air is destructive.
There are different types of roof vents, each varying in size and method of installation.
Static vents are small, square-shaped structures installed along the ridges of roofs. The static vent installation serves primarily to protect the opening, which ventilated air naturally passes through.
Gable vents are the most decorative vent, considering that they are installed in the attic wall, underneath the roof ridge. While not technically being a part of the roof structure, Gable vents allow air to pass through attic space to keep the interior cool.
Ridge vents are the most hidden vents, often blending in with or mistaken for the roof’s actual ridge. This is not a surprise, considering that its location travels along the top-most ridge as a metal sheet. This sheet is covered by shingles and serves to protect small holes made along the roof ridge. Like static vents, the ventilation process occurs by air naturally flowing through these openings.
Turbine vents are the most recognizable with their bulbous, metallic, crown-shaped tops. This vent’s top piece is serrated with small gaps between parts, which allow wind to catch and propel the vent like a pinwheel. The resulting spinning action creates a vacuum in the interior and removes any stagnant air.
Since shingles are exposed to the elements, it is no surprise that a roof’s first line of defence is likely to become damaged throughout its lifetime. Generally speaking, the main destructive forces at work are those caused by severe weather conditions and microbes.
The following are weather-related damages that can be inflicted upon a roof.
High-winds and Debris
An enemy to all shingles alike is high-speed winds. Regardless of how well nailed down or heavy a shingle may be, high-speed winds can find a way to cause some damage. Most asphalt shingles can withstand wind speeds of 90km/hr. However, it is noted that losses will appear at only 50km/hr. Since wind operates like a fluid, it can slide under tiles and slowly rip them away. Additionally, high-speed winds often hurl debris, which can crack shingles. Asphalt shingles, in particular, use sealants to prevent his; however, the bond strength does fade over time.
Complimenting wind damage is water damage, which operates on a slow, but much more severe scale. Water can find its way through even the most minuscule cracks and travel through building materials like concrete, wood, and wallpaper. The nefarious part of this is that water damage can occur without any apparent signs. This means there may be warping, rotting, and mould growth occurring unseen.
While not exactly common, lightning strikes do occasionally hit houses. The resulting strike can blast away shingles, crack concrete, set materials on fire, shatter glass, and fry electronic devices. Other than the visible physical damages, the effects on building materials and electronics can create fire hazards.
Fire damage to roofs almost always occurs internally but can be caused by many reasons. For example, a leaky roof can become a fire hazard, as water can potentially start an electrical fire in the attic. In either case, roof materials that do not have a class A fire-resistance rating are more prone to going up in flames. Such materials are regular asphalt shingles and wood shake, mostly if left untreated. Slate tiles are completely fire resistant. However, their weight can pose a problem if internal wooden structures are compromised.
Hail storms are by-far one of the most destructive environmental forces that a roof can face. The extent of the damage depends mainly on the hail’s size falling, becoming worse, the more massive the hailstones become. Typically though, even small to golf-ball-sized hail is enough to crack all kinds of shingles. Asphalt, Slate, Ceramic, and even metal are not safe from this kind of damage.
Mould, Algae and Fungus Growth
Conversely, some damages are done by small perpetrators in mould, algae, fungus growth, and even insects. Certain materials are exempt from this. However, asphalt and wood shakes are not safe from natural forces of decay.
Mould, algae, and Fungi all operate similarly and also cause similar damages. All three are microorganisms present everywhere and can grow by feeding off of cellulose material if the conditions are right. Typically this means high humidity, heat, and the presence of a food source. Once those are available, these microbes will grow in lumps that can destroy shingles by eating them and uprooting them. Even asphalt shingles are not safe, considering that the limestone content serves as a perfect food source for algae.
Algae and fungal infestations can be apparent when their fruiting bodies are present, but they may also appear as ‘dark streaks’ as an early sign.
Insects and other pests can infest and damage a roof if left unattended. Some shingle materials are immune to them, like clay and slate. However, there are additional structural damages that can occur.
The pests known as ‘powderpost beetles’ are known for infesting and consuming wood products. In nature, they are found in wet logs but can transfer to indoor wood products. These wood products include support, joists, and rafters, which can cause severe damage to your roof over time. The same applies to other usually culprits like termites, which are known to consume wood products.
Damages to roofs can happen, which is why it is essential to know what can be reversed. Most homeowner’s insurance plans work similarly, though specific policies may differ.
Generally, roof insurance covers damages that occur suddenly like hailstorms, fires, or loss caused by wind. Contrary to this, roofs that are old and deteriorating will not be covered, as it is seen as the owner’s responsibility to maintain it.