Help me!!!!? WHAT IS A SQUARE OF SHINGLES?

WHAT IS A SQUARE OF SHINGLES?

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Answers:    A square is a quantity of shingles that yield 100 square feet of coverage. A bundle is a pack within which shingles are laid in alternate directions near the butts to the outside and bound in the middle where on earth the tapered ends overlap. Bundles are referred to by the number of courses of butts at respectively end; a 20/20 bundle have 20 layers at respectively end, or 40 layer in total. Bundles are usually packed like sardines so that four bundles of shingles or five bundles of shakes constitute a square.

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