Metal roof

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Zinc, standing-seam roof in Poland
Flat seam metal roofing was used here on the problem areas. Cauterets, France.

A metal roof is a roofing system made from metal piece, or tiles. It is a component of the building envelope.

Metal roofs protect buildings.

In the United States, metal comprises 10% of the overall residential re-roofing market.[citation needed]


Copper has played a significant role in architecture for thousands of years (see: Copper in architecture). In the 3rd Century B.C., copper roof shingles were installed atop of the Loha Maha Paya Temple in Sri Lanka.[1] And the Romans used copper as roof covering for the Pantheon in 27 B.C.[2] Centuries later, copper and its alloys were integral in European medieval architecture. The copper roof of St. Mary's Cathedral, Hildesheim, installed in 1280 A.D., survives to this day.[3] And the roof at Kronborg, one of northern Europe's most important Renaissance castles (immortalized as Elsinore Castle in Shakespeare’s Hamlet) was installed in the 1585 A.D.[4] The copper on the tower was renovated in 2009.[5]

Earlier metal roofing was a sheeting in the form of corrugated galvanized steel and still find applications today in parts of the developing world. In addition, colour-coated steel roofs are popular in some of the Nordic countries such as Finland and Sweden.




It has been proven that metal roofs do not increase lightning strikes. But if lightning were to ever strike a person's roof, the metal disperses the electricity throughout the structure safely. In fact, it would be safer for a metal roof to be struck by lightning because it’s not flammable or combustible, lowering the risk of a fire.


Metal roofing can be used for residential and commercial buildings. The same material used for metal roofs can be used for siding as well. Metal roofing can also be applied over an existing roof.

Material types[edit]


Several different types of coatings are used on metal panels: anti-rust, waterproofing, heat reflective. They are made of various materials such as epoxy and ceramic.

Untreated Metal roofs absorb and retain heat which causes high building envelope heat loads.

Ceramic coatings can be applied on metal roof materials to add heat reflective characteristic. Most ceramic coatings are made from regular paint, with ceramic beads mixed in as an additive. Although an average ceramic coated roof material reflects 75% to 85% of solar radiations, performance drops by over 30% after a few years due to dirt build-up.[citation needed] Their composition and thickness (from 500 to 1,000 micrometres) can cause cracks to appear, and the color selection is generally limited to white matte finish.

Coatings are sometimes applied to copper.[10][11] Clear coatings preserve the natural color, warmth and metallic tone of copper alloys. Oils exclude moisture from copper roofs and flashings and simultaneously enhance their appearance by bringing out a rich luster and depth of color. The most popular oils are Lemon Oil, U.S.P., Lemon Grass Oil, Native E.I., paraffin oils, linseed oil, and castor oil. On copper roofing or flashing, reapplication as infrequently as once every three years can effectively retard patina formation. In arid climates, the maximum span between oilings may be extended to from three to five years. Opaque paint coatings are used primarily for work applied over copper when substrate integrity and longevity are desired but a specific color other than the naturally occurring copper hues is required.[12] Lead-coated copper coatings are used when the appearance of exposed lead is desired or where water runoff from uncoated copper alloys would ordinarily stain lighter-colored building materials, such as marble, limestone, stucco, mortar or concrete.[13] Zinc-tin coatings are an alternative to lead coatings since they have approximately the same appearance and workability.[14][15] (For more information, see copper in architecture: finishes.)


See also[edit]


  1. ^ Seale, Wayne (2007). The role of copper, brass, and bronze in architecture and design; Metal Architecture, May 2007
  2. ^ Copper roofing in detail; Copper in Architecture; Copper Development Association, U.K.,
  3. ^ Copper Roofing in Detail; Copper in Architecture; Copper Development Association, U.K.,
  4. ^ Kronborg completed; Agency for Palaces and Cultural Properties, København,
  5. ^ Agency for Palaces and Cultural Properties, Renovation of the Tower of Christianborg Palace.,
  6. ^
  7. ^ "Advanced Roofing Solutions: Types of Metal Roofing". Brandon Losik. Retrieved December 30, 2013. 
  8. ^ Austin, Jim (2006). Copper: The peacock of metals, Metal Roofing, April–May 2006;
  9. ^ Copper roofs are cool, Architecture: Working with Copper, Copper Development Association, 2009;
  10. ^ Clear coatings on copper alloys – Technical Report; Copper Application Data, A4027; Copper Development Association
  11. ^ Clear organic finishes for copper and copper alloys; Application Data Sheet 161/0; Copper Development Association Inc.
  12. ^ Finishes – Coatings, Copper in Architecture Design Handbook, Copper Development Association Inc.,
  13. ^ Sternthal, Daniel (2000). Copper flashings in contemporary construction, The Construction Specifier, Magazine of the Construction Specifications Institute, October 2000
  14. ^ The glory of copper; Metal Roofing Magazine, December 2002/January 2003
  15. ^ Sternthal, Daniel 2000. Copper flashings in contemporary construction, The Construction Specifier, Magazine of the Construction Specifications Institute, October 2000
  16. ^
  17. ^ "Maintenance of Metal Roofing". Metal Roofing Source. 11 September 2014. Retrieved 11 October 2014.