GRAVEL ROOFING 255 



one hundred (100) pounds of roofing cement or tar to the square of 

 one hundred (100) feet. All joinings .along walls and around openings 

 to be carefully made. The roof to be then covered with a heavy coating 

 of roofing cement or tar and screened gravel, not less than one (i) cubic 

 yard of gravel to six hundred (600) square feet, gravel to be screened 

 through ^-inch mesh and free from sand and loam. All walls and 

 openings to be flashed. All roofing cement and tar is to be applied hot. 



Six (6) Ply Cap Sheet Wool Felt, Composition and Gravel Roof. 

 First cover the sheathing boards with one (i) layer of dry felt and 

 over this put four (4) thicknesses of wool roofing felt, weighing not 

 less than fifteen (15) pounds (single thickness) to the square of one 

 hundred (100) feet. This felt to be smoothly and evenly laid and well 

 cemented together the full width of the lap, not less than nine (9) 

 inches between each layer, with best roofing cement or refined tar, using 

 not less than one hundred and twenty (120) pounds of roofing cement 

 or tar to the square of one hundred ( 100) feet. The entire surface then 

 to be mopped over with roofing cement or tar and a cap sheet of wool 

 felt applied. All joinings along the walls and around the openings to 

 be carefully made. The roof to be then covered with a heavy coating 

 of roofing cement or tar and screened gravel, not less than one (i) 

 cubic yard of gravel to six hundred (600) square feet, gravel to be 

 screened through 5^-inch mesh and free from sand and loam. All walls 

 and openings to be flashed. All roofing cement and tar shall be ap- 

 plied hot. 



Six (6) Ply Combined Flax and Wool Felt, Composition and 

 Gravel Roof. First cover the sheathing boards with one (i) layer of 

 dry felt and over this put one ( i ) layer of flax felt and three thicknesses 

 of wool roofing felt, weighing not less than fifteen (15) pounds (single 

 thickness) to the square of one hundred (100) feet. This felt to be 

 smoothly and evenly laid and well cemented together the full width 

 of the lap, not less than eleven ( 1 1 ) inches between each layer, with best 

 roofing cement or refined tar, using not less than one hundred and 

 twenty (120) pounds of roofing cement or tar to the square of one 

 hundred (100) feet. The entire surface then to be mopped over with 

 roofing cement or tar and a cap sheet of wool felt applied. All joinings 

 along walls and around openings to be carefully made. The roof to 

 be then covered with a heavy coating of roofing cement or tar and 

 screened gravel, not less than one ( i ) cubic yard of gravel to six hun- 

 dred (600) square feet, gravel to be screened through ^-inch mesh and 



