Slate - Earth-Made Roofing Material

Here are three things you should know about choosing a slate roof.

A Natural Beauty

A slate roof is one of the most beautiful roofs you can put on your home.

Slate begins as shale, geologically compressed over time deep in the earth. The color depends on the minerals present during compression--carbon, iron, mica, etc. After the slate is quarried, slate roofing materials are manufactured by hand.

Most commercial slate is found in the Mid-Atlantic and Northeastern states, though slate is now being imported from overseas, mostly to the Western United States. Most slate is grey or blue-gray in color. There is a large deposit of red slate in New York. Some slate is even mottled with green or purplish deposits.

Maintaining Slate Roofs

Slate can last 75 to 200 years, however it's a good idea to have a slate roof inspected and repaired properly every year. Slate is unique and requires a roofing professional experienced with slate to do the job correctly--as a craftsman.

This natural roofing material deteriorates in a natural way. It continues to evolve even after it has been quarried, cut, sculpted, and placed on your roof. The exposure to hot, cold, wet, and dry climates causes the mineral content to form gypsum. The gypsum literally peels away or "delaminates" off your slate roof tiles. Sometimes the tiles powder, which is visible on the underside of the roof.

Steeper roofs using slate last longer as rains drop quickly off the roof and does not contribute to further deterioration.

Slate Roof Durability

Though slate roofs demand regular maintenance, they have big advantages. They are entirely fire resistant and usually 100 percent leak-resistant. However, slate can last longer than the flashing used in the roofing process. If your slate roof is weathering nicely, but your flashing is deteriorating or has holes in it, you may get a roof leak. Replace flashing as needed.