Benefits of Metal Roofing Over Shingles
Installs over Existing Roof Shingles
Metal roofs have the best strength to weight ratio of any roofing material, allowing metal roofs to be installed over existing roof shingles 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 shingles. Installing over your existing roof shingles eliminates landfill waste and saves labor costs for removing the old 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 addition of subsequent layers of heavy roofing materials such as asphalt shingles can cause structural damage. In these cases, removing the old roofing shingles is usually recommended, but this creates a large amount of landfill waste. In fact, asphalt shingles make up over 3% of all municipal solid waste, or 6.8 million tons annually.
Because metal roofs are so light yet so strong, they can typically be easily installed over your existing roof shingles without the need to add structural reinforcement. The old 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 application is different, so consult your licensed roofing contractor to confirm if your roof is suitable for a metal roof-over installation.