Organic base
Organic shingles have a thick, organic felt base reinforcement. In the manufacturing process, the felt is saturated with a soft, flexible asphalt. It is then completely coated on both sides with tougher coating asphalt and then covered with granules. The result is a tough, durable shingle with excellent durability in extreme cold weather and good performance characteristics in extreme heat. Organic shingles carry a Class C fire resistance rating from Underwriters Laboratories.

Characteristics that equate to high or low quality in an organic base shingle include tear strength, flexibility and cold weather handling. A good organic shingle with tear strength well over 2,000 grams typically will demonstrate excellent cold weather, high wind performance.

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