Coal Tar Pitch Roofing Handbook - 1896 - Page 14
The third Specification is for Vitrified Tile or Brick Roofing, such as is used mainly on massive fireproof structures of the first class.
(To follow description of Concrete, which should be smooth and perfectly graded to carry water to outlet or gutter.)
Over the foregoing shall be laid a five (5) ply Coal Tar Pitch, Felt and Vitrified Tile or Brick Roof, to be constructed as follows:
The Felt shall weigh not less than (14) pounds per one hundred square feet, single thickness.
The Pitch shall be the best quality of straight-run coal tar pitch, distilled direct from American coal tar, and there shall be used not less than two hundred (200) pounds (gross weight) per one hundred square feet of completed roof.
The materials shall be used as follows:
First coat the Concrete (A) with hot Pitch (B) mopped on uniformly. Over the above coating of Pitch lay two thicknesses of Tarred Felt (C), lapping each sheet seventeen (17) inches over the preceding one and mopping back with Pitch (D) the full width of each lap.
Over the Felt thus laid spread a uniform coating of Pitch (E) mopped on. Then lay three (3) full thicknesses of Felt (F), lapping each sheet twenty-two (22) inches over the preceding one.
When the felt is thus laid, mop back with Pitch (G) the full width of twenty-two (22) inches under each lap. Then coat the entire surface with Pitch (H) uniformly mopped on and finish with a course of vitrified clay tiles (I) 6 x 9 x 1 laid in and thoroughly grouted with Portland Cement mortar (J).
Note — Same general specification applies where Brick are used instead of Vitrified Clay Tiles.
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