Metal Roof Specifications
The lowest end metal roofing (thin gauge with acrylic or polyester paints) commonly called AG (agricultural) or Utility panels will last 20–30 years which is roughly 2 times the lifespan of an average asphalt roof. Most metal roofing products today come with warranties from 25 to 50 years. Sheet materials like stainless steel, copper, zinc and aluminum are inherently durable; The oxidization of the base material forms a protective patina. Some modern steel roof sheeting materials are coated with an alloy of zinc and aluminum to give it some of the durability of each of those materials at a lower cost and higher strength than either. Copper and Zinc details have historically been proved to last upwards of 100 years with little or no maintenance. The average life-span of asphalt shingles today(since 2001) is 6–9 years, while residential and commercial grade metal roofing usually lasts from 50-100+ years, depending on the type. The coatings and fixings on steel roof sheeting can be designed for different environments including industrial and marine locations.
Metal roofs are often used to cover large buildings because of their high strength to weight ratio.
Fire and spark resistant
Painted metal roofs are usually snow-shedding. Snow can usually collect when it is fresh and lighter weight. As soon as the ambient temperature rises a couple degrees, the snow usually just slides off. For this reason metal roofing is ideal for homes in northern or mountain regions. Metal is readily recyclable. Most metals can be recycled over and over without losing any valuable properties. Recycling is very efficient. As an example: recycled Aluminum only requires 5% of the energy to produce as does new Aluminum.
Some Steel roofing products can be installed over open framing, or on a solid substrate.
This also includes Large sprung curves and Rolled bull-nose shapes.
Coatings with high reflectivity like Kynar with "cool roof" pigments commonly save 20-30% on air-conditioning costs due to reflecting away much of the sun's heat. Increases the thermal efficiency of buildings in high temperature areas with its cool-roof paints and high emissivity.
Most metal roofing products require very little or no maintenance.
Applications of Metal Roofing
Metal Roofing is a very versatile building material. It is durable. It can be used on residential, commercial, industrial or agricultural buildings. It is not only used in roofing applications, but also may be used as a wall covering. There are many different profiles and styles available to fit most every building situation. One may also combine shapes for aesthetic impact. Using the same material and same color but different shapes can have an impact on curb appeal and building value. Alternativly different metals can be used to create interesting colour combinations.
Metal roofing in New Construction
Metal roofing is ordered per each piece, whether it is in sheet form, trim or ridge material. When properly estimated there is very little waste material in a new project. Sheets can be ordered and cut to exact lengths, allowing for less on the job fabricating.
Metal roofing in Remodeling
Metal roofing is usually easily applied over an existing roof. Especially in situations where labor cost cutting is essential, the added value of not having to remove the existing roof material can be of a large help.
When a Metal roof is used that is called an “AG” or “Utility” grade, these will need recoating once the factory finish wears off or corrosion will occur. These paints are commonly Acrylic or Polyester based. Roof coatings are the preferred material since they are able to stay elastic and withstand the thermal cycling that occurs in metal roofs.
Roofing materials made from Stainless Steel, Zinc or Copper will rarely require maintenance over their lifetime. Usually the maintenance is required due to design or installation mistakes as these materials can commonly last over a century. Metal roofing with long life paints like Kynar should not normally require maintenance until the paint fails. These products have been used for over half a century now in the U.S. and few installations have failed. So these roofing products should be considered a lifetime product.