Roofing that provides inadequate defense against hailstorms, wind, rain and snow or does not protect against possible home invasion by insects, rodents and birds is a poor investment indeed. Metal roofing provides excellent defense in all of these areas. Yet, installation costs often are higher than costs for wood shingles or composite roofing materials. To determine whether roofing with metal makes sense, consider the following:
Expected Life of the Building
Metal roofing has one of the longest life expectancies of any roofing choice. Some certain metal roofs, including some stainless steel and copper roofs can last over 100 years. That being said, it is more expensive than some other options, like a composite roof, so if you are looking to roof, or re-roof a structure that is likely to be torn down, abandoned, or potentially rezoned in the foreseeable future, it will make more financial sense to choose a less expensive option: wood shingles or composite roofing might be the best investment. If, however, the building is likely to be used for more than 30 years, roofing with metal is certainly a wise choice as it will certainly last and will require little maintenance throughout its life.
Roof Pitch
In order to install metal, the roof needs to slope to allow water, snow, or anything else that falls on it to run off. A pitch of 3:12 or more is preferred. This means that for every horizontal foot, the roof rises three inches. If you do have a low-slope roof, there are some metal panel systems that are engineered to be installed and function on lesser slopes. Metal does not work well on flat roofs. There are special roof systems and materials for flat roofs, include torch-down and PVC membrane.
Weather Conditions and Climate
If the building to be roofed is located in an area that experiences high wind speeds, metal is an excellent choice. The material itself is very strong and it is often screwed or attached using very secure screws or fasteners tied directly into the structure. Where you might lose shingles during a windstorm, it would take an immense amount of wind to damage your metal roof.
In warm climates, metal has a strong advantage, as well. Metal reflects heat from the sun's rays instead of letting it through to the building's interior. This can result in substantial energy savings. In colder climates, foam-backed metal roofing is a good choice. Another way to prevent heat loss is to insulate the attic. Metal roofs shed snow and ice better than either wood shingles or composites and are definitely a great choice for structures that accumulate large amounts of snow or ice.
Most metal roofs work well in damp climates. Metal is unaffected by mold, mildew or moss. Rust can be a problem, however, if the metal is of iron or steel that has not been coated or if the coating gets scratched. This can be made worse if the roof is allowed to accumulate a lot of debris like pine cones or pine needles (although most properly sloped metal roofs do an excellent job of shedding most debris naturally with wind and rain).Do note that damp weather can make a metal roof dangerous to walk on. Wet metal is slick. Add to that a roof with a steep pitch, and one has the recipe for disaster. Walking on a metal roof requires careful adherence to safety measures designed to prevent or arrest falls.
Wood shingles tend to curl or crack over time. Dry shingles and composites sometimes become so brittle that they break when winds hit or they are struck by hail. Metal roofing expands and contracts with changing temperatures but does not become deformed. Objects that strike it will usually do no more than make a slight indentation.
Structural Strength
Overall strength of the building as well as truss strength and strength of materials used as underlayment must be considered in determining the type of roofing to install. Not only does one need to consider the added weight of the roofing itself, one must contemplate the possibility of extra weight caused by adverse weather.
Roof snow and ice can stress a building beyond its structural strength. A one-inch layer of ice weighs approximately the same as one foot of new snow, and a cubic foot of new snow averages five pounds. Old snow weighs more. In areas that get a lot of snow in the winter or that experience periods of alternating snowfall and freezing rain, the weight of an accumulation of heavy snow or ice on the roof can cause an entire building to collapse.
A roof covering of smooth metal combined with a steep roof pitch is the best insurance against snow and ice buildup. It also is the best roofing for preventing ice dams. If an ice dam does form, it is unlikely to cause damage to the building because water usually cannot find its way around or through the metal.
Appearance
Some buildings would look very strange with roofs that did not match the style of the building. Stucco houses, for example, traditionally have roofs of clay tile. A roof of batten or standing seam metal sheeting might look odd.
In the past, choices in roofing materials made of metal were limited. Now, however, metal roof materials exist that fit any building style. For example, one type of stone granule-coated steel gives the appearance of clay tile at less cost and lower weight. Easy to install, it requires little maintenance and is resistant to damage from windstorms, hail and earthquakes. For pictures that give an idea of what's available, click on Trending Now: Metal Roofs.
Noise
Both composite roofing and wood shingles reduce sound better than plain metal. Sound travels right through metal. Installing a metal roof over a home or other building that has nothing between the roof and the building's interior to reduce sound will allow the sound of falling rain or hail to travel directly from the metal to the building's occupants. Noise reduction is easy, however. Insulation absorbs sound. So do certain types of ceiling tiles, but it is worth noting that a metal roof comes with more potential for noise.
Fire Safety
For roof protection against flying embers, metal makes sense if what is directly underneath it is heat tolerant. Composites that contain asphalt or plastics either melt or ignite if temperatures get hot enough, and untreated wood shingles catch fire easily. Methods have been developed to improve the fire resistance in all roofing materials. However, non-flammable materials like metal, clay and slate remain the best options.
Resale Value
Low-cost roofing materials add little to the value of a commercial building or home. In fact, poor-quality roofing may cause the value to drop. Buyers know the value of a metal roof, however. Prospective buyers are impressed by the fact that they will not have to replace the roof or do intensive maintenance to keep the roof and the building sound. If you plan to sell sometime in the future, installing a metal roof makes a lot of sense.
Environmental Factors
To be environmentally friendly, roofing materials either need the ability to decompose or to be recycled. Burning is not an option, and burning roofing materials that contain plastics or other man-made chemicals pollutes the air.
Roofing made of organic materials will decompose if left on the ground or buried. Wood shingles in their original form are organic. Most wood shingles in use today, however, contain chemicals from being treated for resistance to fire and decay.
Composite roofing materials often wind up in landfills, although there are some recycling programs now that can be used in pavement. However, roofing materials made of metal often are manufactured from recycled materials and can be recycled themselves later on. Almost 100 percent of the metal in such roofing is reclaimed. Did you know that aluminum is infinitely recyclable, meaning that no new materials are needed to melt it down and form it into something new?