Why does slate make a good roofing material?
Of all the dimension stone types, slate is the most anisotropic in its behavior and properties with a very pronounced rift. These cleavage planes allow slate to be split into very thin sheets with exceptionally high flexural strength. The combination of easy splitting characteristics and exceptionally high flexural strength allow its use in 3/16" (5 mm) thick roofing materials. It is the only dimension stone type to be used in this application.
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slate is a mudstone that is both impermeable and non-porous. In addition is is flat. This means water will run off and not collect in puddles on it and it can be placed on a roof in a regular manner.
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Of all the dimension stone types, slate is the most anisotropic in its behavior and properties with a very pronounced rift. These cleavage planes allow slate to be split into very thin sheets with exceptionally high flexural strength. The combination of easy splitting characteristics and exceptionally high flexural strength allow its use in 3/16" (5 mm) thick roofing materials. It is the only dimension stone type to be used in this application.
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Slate is a very dense metamorphic rock. It has clevage planes that allows it to conform into flat shapes, fitting the society's definition of a "good roof".
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