Installing Metal Roofing Over Shingles

Installing Metal Roofing Over Shingles

Scott Hailstone/E+/Getty Images 1. Metal Roofs Are Not Just In Architectural Digest AnymoreMetal roofs used to be found only on architect-designed houses. No longer a novelty, metal roofing is increasingly found on more conventional houses.2. Metal Roofing Can Be Installed Over Your Existing RoofMetal roofs can be installed over your existing roof without tearing off shingles. While shingle removal is the preferred route, it is also messy and raises the cost of the job.  Water vapor in conjunction with a metal roof on existing shingles is a problem.  Water vapor build-up and attendant mold and rot are not reasons alone to avoid installing metal over shingles. Roofers can install a vented metal roof can be installed over existing shingles which would eliminate the vapor problem.Also, installing the metal roof on top of furring strips (1×3's or similar) will raise the metal and provide an air pocket between it and the shingles.3. They Are No Noisier Than Asphalt RoofingSurprisingly, properly installed metal roofing is no noisier than any other type of roof. Metal roofing is typically installed over a solid substrate. Additionally, the attic and insulation provide a sound barrier. If you wish to install metal roofing over your existing roof, the metal roof will most likely be raised over the existing roof by means of furring strips. These furring strips will create an air pocket which will further deaden sound. 4. Metal Roofing Does Not Attract Lightning More Than a Conventional RoofsYes, it does seem like metal roofing would attract lighting, but this is faulty logic.According to a technical bulletin from the Metal Construction Association, “Metal roofing does not in any way increase [the risk of a lightning strike.” Not only that, but if metal roofing does happen to get struck by lightning, it is less combustible than conventional roofing materials such as shake shingles.As the bulletin asserts:Because metal roofing is both an electrical conductor and a noncombustible material, the risks associated with its use and behavior during a lightning even make it the most desirable construction available.5. Their Warranted Lives Are Equal To Conventional Roofing ProductsIf you live in fire-prone areas, such as Southern California, metal roofing will extinguish any embers. Insects such as termites can never eat metal roofing.  Metal roofing is impervious to rot and mildew.Because it conducts heat quickly from the sun, snow slides off more quickly than with conventional roofing.Even so, most metal roofing manufacturers will warrant their products only for an average of 30 years, which is about the same as conventional roofing manufacturers.6. Metal and Low-Pitched Roofs Are Like Peas In a PodBecause metal roofing comes in larger sheets and the pieces are so tightly sealed together, you can install metal roofing on gently pitched roofs.7. In Severe Hailstorms, They May Be Irreparably DamagedMetal roofing will weather pea-sized hailstorms. But if your area ever experiences severe hailstorms with larger stones, your aluminum or copper roof may get dented. Steel is harder and will fare better in the event of a hailstorm.8. Modifying Metal Roofing Is Next-To-Impossible For HomeownersAsphalt shingles are easy to replace because they are available at your local home improvement store and because you are working with small pieces.Metal roofing, on the other hand, is generally available only through select retailers. Also, the large sheets are difficult to handle and fabricate unless you are a professional.9.  Ridge Venting Will Be More ObviousOn a shingled roof, the continuous ridge vent (CRV) is the strip of shingle-like material that runs the entire length of the peak of the house, masking outflow holes.On composite roofs, you have seen this countless times but probably never noticed.  One reason is because the CRV lies very flat.  Also, the two materials blend in with each other so well.On your metal roof, the CRV will be metal and will stand out a bit farther and be more obvious.  However, these thick, prominent lines or ridges are inherent in metal roofs and add to their distinctive look. Read More
installing metal roofing over shingles 1

Installing Metal Roofing Over Shingles

1. Metal Roofs Are Not Just In Architectural Digest AnymoreMetal roofs used to be found only on architect-designed houses. No longer a novelty, metal roofing is increasingly found on more conventional houses.2. Metal Roofing Can Be Installed Over Your Existing RoofMetal roofs can be installed over your existing roof without tearing off shingles. While shingle removal is the preferred route, it is also messy and raises the cost of the job.  Water vapor in conjunction with a metal roof on existing shingles is a problem.  Water vapor build-up and attendant mold and rot are not reasons alone to avoid installing metal over shingles. Roofers can install a vented metal roof can be installed over existing shingles which would eliminate the vapor problem.Also, installing the metal roof on top of furring strips (1×3's or similar) will raise the metal and provide an air pocket between it and the shingles.3. They Are No Noisier Than Asphalt RoofingSurprisingly, properly installed metal roofing is no noisier than any other type of roof. Metal roofing is typically installed over a solid substrate. Additionally, the attic and insulation provide a sound barrier. If you wish to install metal roofing over your existing roof, the metal roof will most likely be raised over the existing roof by means of furring strips. These furring strips will create an air pocket which will further deaden sound. 4. Metal Roofing Does Not Attract Lightning More Than a Conventional RoofsYes, it does seem like metal roofing would attract lighting, but this is faulty logic.According to a technical bulletin from the Metal Construction Association, “Metal roofing does not in any way increase [the risk of a lightning strike.” Not only that, but if metal roofing does happen to get struck by lightning, it is less combustible than conventional roofing materials such as shake shingles.As the bulletin asserts:Because metal roofing is both an electrical conductor and a noncombustible material, the risks associated with its use and behavior during a lightning even make it the most desirable construction available.5. Their Warranted Lives Are Equal To Conventional Roofing ProductsIf you live in fire-prone areas, such as Southern California, metal roofing will extinguish any embers. Insects such as termites can never eat metal roofing.  Metal roofing is impervious to rot and mildew.Because it conducts heat quickly from the sun, snow slides off more quickly than with conventional roofing.Even so, most metal roofing manufacturers will warrant their products only for an average of 30 years, which is about the same as conventional roofing manufacturers.6. Metal and Low-Pitched Roofs Are Like Peas In a PodBecause metal roofing comes in larger sheets and the pieces are so tightly sealed together, you can install metal roofing on gently pitched roofs.7. In Severe Hailstorms, They May Be Irreparably DamagedMetal roofing will weather pea-sized hailstorms. But if your area ever experiences severe hailstorms with larger stones, your aluminum or copper roof may get dented. Steel is harder and will fare better in the event of a hailstorm.8. Modifying Metal Roofing Is Next-To-Impossible For HomeownersAsphalt shingles are easy to replace because they are available at your local home improvement store and because you are working with small pieces.Metal roofing, on the other hand, is generally available only through select retailers. Also, the large sheets are difficult to handle and fabricate unless you are a professional.9.  Ridge Venting Will Be More ObviousOn a shingled roof, the continuous ridge vent (CRV) is the strip of shingle-like material that runs the entire length of the peak of the house, masking outflow holes.On composite roofs, you have seen this countless times but probably never noticed.  One reason is because the CRV lies very flat.  Also, the two materials blend in with each other so well.On your metal roof, the CRV will be metal and will stand out a bit farther and be more obvious.  However, these thick, prominent lines or ridges are inherent in metal roofs and add to their distinctive look.
installing metal roofing over shingles 2

Installing Metal Roofing Over Shingles

home products how to buy Get an Estimate F.A.Q. Metal’s Benefits Literature Installation Videos news & Events about us contact Find a Contractor Photo Gallery Virtual Roofer Benefits of Metal Roofing Over Shingles Recyclable Energy Efficient Reduces Urban Heat Island Effect Installs over Existing Roof Systems Low Maintenance / Long Life Green Product WeatherResistance EnergyEfficiency CurbAppeal GreenProduct LifecycleCosts Benefits of Installing Metal Roofing Over Shingles Metal roofs have the best strength to weight ratio of any roofing material, allowing metal roofs to be installed over existing asphalt shingle roofs without the need to add structural support to the roof. Union’s steel roofing panels weigh 50% to 65% less per square foot than most asphalt roofing shingles. Installing metal roofing over your existing asphalt shingle roof eliminates landfill waste and saves labor costs for removing the old asphalt roof shingles. Most roof types simply weigh too much to be installed over top of one another without adding additional structural support to the roof. Roofs are designed to support a predetermined amount of weight and the installation of subsequent layers of heavy roofing materials such as asphalt roofing shingles can cause structural damage. In these cases, removing the old asphalt roofing shingles is usually recommended, but this creates a large amount of landfill waste. In fact, asphalt roofing shingles make up over 3% of all municipal solid waste, or 6.8 million tons annually. Installing metal roofing over shingles can help solve these issues. Because metal roofs are so light yet so strong, metal roofing panels can typically be easily installed over your existing asphalt roof shingles without the need to add structural reinforcement. The old asphalt roof shingles under the metal roof simply serve as an extra layer of insulation and water protection and pose no problems to the new metal roof. Of course, each metal roofing over shingles installation is different, so consult your licensed metal roofing contractor to confirm if your roof is suitable for a metal roofing over shingles installation.

Installing Metal Roofing Over Shingles

Installing Metal Roofing Over Shingles
Installing Metal Roofing Over Shingles