Roof Systems FAQ
COOL ROOFING SYSTEMS:
What is a cool roof?
Cool roofs, also called white roofs, are a highly reflective and emissive roof coatings that stays 50 to 60 degrees F cooler in the summer sun, thereby reducing energy costs, improving occupant comfort, cutting maintenance costs, increasing the life cycle of the roof, and contributing to the reduction of urban heat islands and associated smog.
What kinds of roofing products are available for residential applications?
There are several. Check out our articles about the different types of roofing systems available by clicking here
How cool is a cool roof?
During the summer, a typical dark roof is 150 to 190 degrees Fahrenheit at peak, while cool roofs peak at 100 to 120 degrees Fahrenheit.
SLATE ROOF SYSTEMS:
How much does a slate roof cost?
A simple, straightforward slate roof starts out at $12 per square foot and can run more than $20 per square foot depending on the type of slate used, the design of the roof, the height of the building, the pitch of the roof, and so forth. Most slate roofs run between $12 and more than $20 per square foot, installed.
Besides the low life cycle cost, why else should one install a slate roof?
Aesthetics: Slate roofs come in a wide variety of sizes, colors, and thicknesses. One can create many different looks to enhance just about any architectural style. Click here for GAF/ELK’s virtual design studio to get a visual perspective on styles and colors of slate roofing.
Ecological considerations: Slate is a natural product that comes out of the ground and can safely go back into the ground. Petrochemical roofing made of asphalt and fiberglass typically lasts twenty years. According to statistics, construction and demolition debris make up 28% (by weight and volume) of the refuse being placed in landfills. That is more than the waste from Styrofoam, fast-food packaging, disposable diapers, and all plastic packaging combined! Approximately 20% of all construction debris is roofing. Though not the only reason, environmental concern is certainly a good reason for installing slate.
Effective protection: A slate roof is the best chance you have for getting a leak-free roof. Most leaks in roofs occur in flat areas and areas with protrusions. Since slate roofs are installed by craftsmen who are thinking in service life of decades or even centuries, these details are usually installed with great care. As a result, the quality of leak protection is much higher. Thus slate roofs leak much less often than other kinds of roofing — especially on houses with complicated roof lines. Slate roofs are much more wind resistant than asphalt roofs. Slate roofs also do not rely on the underlying roofing felt to remain leak proof the way many clay and concrete tile roofs do.
Long-term Reliability: Slate has been the material of choice for a large percentage of the most important buildings built in the last five centuries. The method of installation has changed little over five centuries. New roofing products, such as many of the simulated slates, have come and gone in less time than asphalt roofs last. Some of these products have been sold with 50-year warranties, which became worthless when the businesses went under.
Is a slate roof fireproof?
Slate itself is fireproof. A slate roof is one of the most fire resistant roofs that exist. However, the wood deck under the slate is not fireproof. Often fires will jump from house to house as sparks hit adjacent roofs, igniting the surface if it is a flammable material. Many of the raging fires that engulf hundreds of houses every year would not occur if the houses were covered in slate.
Does a slate roof need to be cleaned periodically?
No. Slate requires no cleaning
Does a slate roof need periodic maintenance?
Yes. Even new slate roofs will shed a few slates from time to time. It is a good idea to visually inspect a slate roof at least once a year. The owner of the property can do this annual inspection. Any slates that are seen to be missing, sliding, or broken should be replaced every few years. It is always a good idea to have a more careful inspection from a slate roof expert.
Are there any special framing or structure considerations for slate?
A good solid deck with 16” on center framing is preferred. Most structures are built to handle wind and snow loads that far exceed the weight of slate. However, a weak structure that has too much flex to it will result in a poorly installed slate roof. Ideally, one would use a 3⁄4” thick tongue and groove deck on 2” x 12” rafters 16” on center. However, this is an expensive deck, and would be a rare sight today. Otherwise, it would be best to have at least 5/8” plywood or 3⁄4” plywood over 16” on center trusses built to handle slate.
METAL ROOFING SYSTEMS:
Why should I spend a little more for a metal roof?
Ordinary roofing materials have shorter life spans than metal and will need to be replaced regularly. With constantly increasing material and labor costs, that could mean a significant expense over the life of your building. A metal roof virtually never needs to be replaced, saving you money while adding value to your residential or commercial structure.
How much protection does a metal roof offer?
FIRE: A metal roof will not burn or support combustion.
WIND: Experience at recent hurricanes has shown that metal roofs outperformed other roofing products.
WATER: A metal roof has a low rate of water absorption, greatly reducing damage to structure. And a metal roof cannot be penetrated by hail.
How can a metal roof save money on energy bills?
Metal reflects the majority of the sun’s rays, so it doesn’t retain as much heat as wood, asphalt shingles, tile or cement. This means a metal roof could help your attic stay cooler longer – leading to a significant reduction in your building’s energy bills.
Is a metal roof noisy when it rains?
Contrary to popular belief, metal roofs are not noisy when it rains. In fact, according to one study, metal roof’s noise levels are about the same as other products like asphalt shingles, wood shingles or clay tiles.
Can I walk on my metal roof?
Yes, but since a metal roof requires virtually no maintenance, there should be no reason to do so. Like any roof, care should be exercised. You can discuss specific details about walking on your metal roof with your installation company.
Does my present roof have to be removed before a metal roof is installed?
In most applications over asphalt, our metal roofs can be applied directly over the old roof, saving money and eliminating a great deal of mess. In addition, because there is no old roof to dispose of, landfill space is spared, helping to protect our environment.
How much do these metal roofs weigh in comparison to other types of roofing?
Metal roofing materials are less than one-third the weight of asphalt, one-twentieth the weight of concrete, and add less than 10% to the weight of the existing roof materials.
Does the roof need to be grounded?
Grounding of any exterior metal siding or roofing is not recognized as necessary by any major building code organization. Occasionally, certain municipalities or local building codes may require it. Detailed grounding instructions are available. Because metal roofing is both an electrical conductor, and a noncombustible material, the risks associated with its use and behavior during a lightning event make it the most desirable construction material available.
How long will a metal roof last?
A metal roof won’t dry out, split, curl, peel or flake like conventional roofing products. Metal roofing has been successfully used for centuries and they last substantially longer than any other roofing product on the market.
CLAY AND TILE ROOFING SYSTEMS:
How long do tile roofs really last?
No one knows for sure. Tile roofs date back to Neolithic China, and many
Ancient structures with tile roofs still exist. In Europe and Asia roof tiles have
been the primary roofing product for hundreds of years. Both clay and concrete
Tile roofing systems, when installed properly, will withstand weather conditions
that begin to deteriorate other roofing products the day they are installed. In
general, a tile-roof, clay or concrete – may outlast the building it protects.
Are roof tiles available in shapes other that Spanish
or Mediterranean?
Yes. Roof tiles come in many colors, shapes and sizes. In fact, with
modern innovations, clay and concrete roof tile manufacturers produce tiles
that suits any architectural style, from authentic Spanish and Mediterranean to
New England Colonial, historic or contemporary. Roof tiles can be flat or
round, simulate wood shakes, or slate replicate centuries-old roofing materials.
The possibilities are virtually limitless.
ENVIRONMENTALLY FRIENDLY: Both clay and concrete roof tiles are made
from naturally occurring materials that do not deplete precious natural
resources. They are manufactured without chemical preservatives. And old
tiles can be recycled to make new tiles or other products.
COST EFFECTIVE: With superior aesthetics, durability and longevity, roof tile
is a cost-effective alternative to other roofing products. A simple comparison
of life cycle costs makes it clear that a tile roof is one of the best available today.
“I saw a news picture of a home with a tile roof surrounded by
homes burned to the ground.
Do tile roofs protect my home from fire better than other roofing materials?
Clay and concrete tiles are completely non-combustible. The complete roof
assembly has a Class “A” fire rating, the highest fire resistant rating available.
Buildings with Class “A” rated tile roof systems should be eligible for the
lowest fire insurance rates.
What about the insulation value of a tile roof?
Tile roofs are good insulators. The combined effect of the roof tiles, air space, and decking allows for better air circulation and reducing direct heat transfer. This should lower energy costs year round. Aesthetically pleasing, more durable than other roofing materials, and able to withstand extreme weather conditions, tile has been the first roofing choice in Europe and Asia for centuries. Tile’s durability has been clearly demonstrated by how well it has withstood the test of time, weather and natural disasters. Tile perfectly complements the architectural styling of any home or building. There is tile that duplicates wood shake; just right for that ranch-style home. There’s tile that replicates slate; a fitting choice for the Tudor style and of course the rounded tiles are ideal for Spanish and Mediterranean structures. The lifecycle cost of tile (annual cost over its expected life)is much less than metal, treated wood shakes, asphalt, or fiberglass shingle
roofs. This makes tile a natural choice; not just for durability, but also for its long-term economical benefits. To ensure that tile roofing continues the traditions of excellence, the Tile Roofing Institute member companies are constantly testing their products in extreme, real-world conditions. Striving for continuous improvement, the Tile Roofing Institute member companies have demonstrated that buildings with tile roofs provide the greatest protection and best value of any roofing material. Every year, regardless of the part of the country, wild fires devastate hundreds of homes.
In independent testing, concrete and clay tile roofing has proved to be safer than traditional
roofing materials such as shingles, wood shake or metal. By design, a tile roof is allowing air circulation under the tile, which reduces heat transfer to the attic during a fire. For homeowners living in an area prone to tornadoes, hurricanes or extreme winds, roof tile provides one of the best defenses against weather-related property damage. One of the best attributes of concrete and clay tile roofing is its resistance to severe storms and hurricane-force winds. Its design and construction provide high air permeability, which helps relieve wind stress. Independent testing sponsored by the Tile Roofing Institute has shown that with proper attachment, clay and concrete roof tiles can sustain winds in excess of 125 miles-per hour that would have stripped off most other roofing materials. Different parts of the country are susceptible to devastation from extreme hailstorms. Clay and concrete roof tiles can resist damage from hailstones as large as 1.5”, just larger than a golf ball. A tile roof system provides two layers of protection from the elements. The tile itself provides a tough water-shedding outer shell. An underlayment of asphalt roofing paper over the roof decking provides the inner shell if the tile was struck by extremely large hailstones. This is real protection that few other roofing systems can provide. Independent testing at the University of Southern California has shown that clay and concrete tile roofing systems, when installed according to building code standards, exceed current seismic load requirements for building materials.