Page:Architectural Review and American Builders' Journal, Volume 1, 1869.djvu/561

 1869.] Table of Slates. 451 TABLE OF SLATES: SHOWING THE NUMBER OF EACH SIZE OF SLATE REQUIRED FOR ONE SQUARE OF ROOF. Size. No. Size. No. Size. 1 No. 6 x 12 533 9 X 16 246 12 x 20 141 7 X 12 457 10 X 16 221 14 X 20 121 8 X 12 400 12 X 16 184 11 X 22 137 9 X 12 355 9 X 18 213 12 X 22 126 7 X H 374 10 X 18 192 14 X 22 108 8 x 14 327 11 X 18 175 12 X 24 114 9 x 14 291 12 X 18 160 14 X 24 97 10 X 14 261 10 X 20 169 16 X 24 86 8 X 16 272 11 X 20 154 A Square of Slate is what will meas- ure one hundred square feet, when upon the Roof. Whenever Slates are purchased by the square, it has become an invariable rule, to allow three inches for the dis- tance the third covers the first, or, to use the technical phraseology of Slaters, three inches over-lap. The contents of a roof is found by multiplying the length of the ridge by the girt from eave to eave ; and, in Slating, just so much allowance must be made, for the double row of slate at the eaves, as there would be in a single row of slate. For example, if the slates are sixteen inches long, they will lay six and a half inches to the weather, therefore six and a half inches should be allowed. One foot, linear measure, is allowed, on valleys and hips, for the extra labor of cutting, fitting, and laying, and the waste of slate. Example: if a valley or hip is twenty feet long, twenty feet will be added to the surface measure of the roof. No deduction is made for chimneys, scuttles, &c, unless they are more than four feet square We have been indebted, for the above information, to the kindness of a friend, who is a practical Slater ; and with his assistance and the aid of a very use- ful little book, called "The Slater's Guide," we have been enabled to com- plete the foregoing Table, which may be useful to those not familiar with the mode in which slate is employed for roofing purposes ; and the method of measuring a roof, when so covered. The above is a practical and common- sense view of the subject, such as comes into every day's notice and practice, and upon which all contracts are invariably based. Indeed, so universally known is the formula, which we have here given, among all business men, who have any building operations, that, even when there is no contract made, it forms the basis of the settlement, for the work undertaken and completed, on a mere verbal understanding.