183. Before taking up the subject of bricklaying, the student should become acquainted with the laws for the thickness of walls in this country. For this purpose, an extract is given from the building law of New York, relating to the thickness of brick walls in proportion to their height. The laws of other cities do not vary materially from the New York law, and it can be safely taken as a standard.

184. Dwelling Houses

Dwelling Houses. "The basement walls of dwelling houses not over 35 feet in height and not over 20 feet in width shall not be less than 12 inches thick, if of brick; the other walls shall not be less than 8 inches thick; but no party wall in any such building shall be less than 12 inches thick. (See Fig. 60.)

"The walls of all dwelling houses, whether called tenement houses, apartment houses, flats, hotels, or other buildings, which are to be used for residence purposes, and are 26 feet or less in width between walls, and also the walls of schoolhouses over 35 feet in height and not over 50 feet in height, shall not be less than 12 inches thick above the foundation wall; but no wall shall be built having a 12-inch thick portion measuring vertically more than 50 feet. [See (a) and (b), Fig. 61.]

"If over 50 feet in height and not over 60 feet in height, the walls shall not be less than 12 inches thick above the basement, if a high-stoop house, and not less than 16 inches in the first story if not a high-stoop house. [See (a) and (b), Fig. 62.]

"If over 60 feet in height and not over 75 feet in height, the walls shall not be less than 16 inches thick to the height of 25 feet, or to the nearest tier of beams to that height, and from thence not less than 12 inches thick to the top. (See Fig. 63.)

"If over 75 feet in height and not over 85 feet in height, the walls shall not be less than 20 inches thick to the height of 20 feet, or to the nearest tier of beams of that height, thence not less than 16 inches thick to the height of 60 feet, or to the nearest tier of beams of that height, and from thence not less than 12 inches to the top. (See Fig. 64.)

184 Dwelling Houses 62

Fig. 60.

184 Dwelling Houses 63

Fig. 61.

184 Dwelling Houses 64

Fig. 62.

184 Dwelling Houses 65

Fig. 63.

184 Dwelling Houses 66

Fig. 64.

184 Dwelling Houses 67

Fig. 65.

184 Dwelling Houses 68

Fig. 66.

"If over 85 feet in height and not over 100 feet in height, the walls shall not be less than 24 inches thick to the height of 35 feet, or to the nearest tier of beams to that height, thence not less than 20 inches thick to the height of 75 feet, and from thence not less than 16 inches thick to the top. (See Fig. 65.) "If over 100 feet in height and not more than 115 feet in height, the walls shall not be less than 28 inches thick to the height of 25 feet, or to the nearest tier of beams to that height; thence not less than 24 inches thick to the height of 50 feet, or to the nearest tier of beams of that height; thence not less than 20 inches thick to the height of 90 feet, or to the nearest tier of beams of that height, and from thence not less than 16 inches thick to the top. (See Fig. 66.)

184 Dwelling Houses 69

Fig. 73.

184 Dwelling Houses 70

Fig. 72.

184 Dwelling Houses 71

Fig. 71

184 Dwelling Houses 72

Fig. 70.

184 Dwelling Houses 73

Fig. 69.

184 Dwelling Houses 74

Fig. 68.

184 Dwelling Houses 75

Fig. 67.

"If over 115 feet in height, each additional 25 feet in height, or part thereof, next above the curb, shall be increased 4 inches in thickness, the upper 115 feet of wall remaining the same as specified for a wall of that height. (See Fig. 67.)

"Eight-inch partition walls may be built to support the beams in such buildings in which the distance between the walls is not over 33 feet, providing that no clear span is over 26 feet; but no such brick partition wall shall be built having an 8-inch thick portion measuring vertically more than 50 feet.

185. "The walls of all warehouses, stores, factories, and stables 25 feet or less in width between walls shall not be less than 12 inches thick to the height of 40 feet. (See Fig. 68.)

"If over 40 feet in height and not over 60 feet, the walls shall not be less than 16 inches thick to the height of 40 feet or to the nearest tier of beams to that height, and from thence not less than 12 inches to the top. (See Fig. 69.)

" If over 60 feet in height and not over 75 feet in height, the walls shall not be less than 20 inches to the height of 25 feet or to the nearest tier of beams to that height, and from thence not less than 16 inches thick to the top. (See Fig. 70.)

"If over 75 feet in height and not over 85 feet in height, the walls shall not be less than 24 inches thick to the height of 20 feet, or to the nearest tier of beams to that height; thence not less than 20 inches thick to the height of 60 feet, or to the nearest tier of beams to that height, and thence not less than 16 inches thick to the top. (See Fig. 71.)

"If over 85 feet in height and not over 100 feet in height, the walls shall not be less than 28 inches thick to the height of 25 feet, or to the nearest tier of beams to that height; thence not less than 24 inches thick to the height of 50 feet, or to the nearest tier of beams to that height; thence not less than 20 inches thick to the height of 75 feet, or to the nearest tier of beams to that height, and thence not less than 16 inches to the top. (See Fig. 72.)