Appearance

• Metal roofing is manufactured into 4-foot panels with ribs on each end. Once crafted from steel, metal panels are now available in corrosion-resistant coatings and in a variety of colors. Aluminum shingles, available in many colors and textures, resemble modern asphalt architectural shingles or terra cotta tiles.
  
  

Durability

• Metal roofs have lengthy lives; rustproof aluminum generally lasts longer than steel metal panels. Modern applications of zinc and epoxy coatings have increased the lifespan of steel panels. Manufacturers commonly offer 50-year transferable warranties on their products.
  
  

Installation

• Both roofing types require professional installation for best performance. Metal panels, installed in large sheets, are screwed slightly off the flat roof decking and interlock with each other. Aluminum shingles are pieced together directly installed to the decking with high-grade nails.
  
  

Underlayment

• Aluminum shingles are installed over a special synthetic underlayment that helps protect the roof decking from moisture. Metal roof panels do not utilize any special underlayment; in fact, metal roofing may be installed directly over the roofing deck or up to two layers of existing asphalt roofing material.
  
  

Cost

• Aluminum shingles are more expensive than metal roofing, but they have a slightly lengthier lifespan and better construction, because aluminum will not corrode.