Note. Wherever a tenant is made, the length of the piece must be taken from the ends of the tenants, and not from the shoulders. If the floors are fixed in the building, the distance the timber goes into the wall, which is about of the thickness of the wall, must be added to the length of their respective pieces that are clear of the walls. Before I proceed to give an example in measuring a floor, it will be proper to explain the several pieces of timber that constitute the same. EXPLANATION OF THE TIMBER IN A FLOOR. Let Plate 57, Fig. 1, be the plan of a naked floor, Fig. 2 and 3 are sections each way; the girder is marked A, and the section of its end is marked a in Fig. 3; the binding joists are marked B, B, B, B, &c. the sides are marked b, b, in Fig. 3; the ends are marked b, b, b, b, in Fig. 2; the bridging joists are marked C, C, C, &c. in the plan at Fig. 1, the ends are marked c, c, c, &c. at Fig. 3, and the side is marked c at Fig. 2; the ceiling joists do not appear on the plan at Fig. 1, because of the bridging joists appearing before them; the ends are marked e, e, e, at Fig. 3, and the sides are marked e, e, e, &c. at Fig. 2. EXAMPLE. Let Fig. 1, Plate 57, be the plan of a floor, as before; suppose the girder, marked A, to be 1ft. broad, 1ft. 2in. deep, and 20ft. long; there is 8 bridging joists marked C, C, C, &c. whose scantlings are 3in. by 6in. and 20ft. long, that is of the same length with the girder; there is also 8 binding joists, whose lengths are 9ft. and their scantlings are 8in. by 4in.; the cieling joists are 24 in number, cach 6ft. long, 4in. by 2in.; required the solidity of the whole, either for materials or workmanship. 1 i. ii 6 6 3 17 6iii area of the end of a bridging joist. 8 1 Oii Oiii add 1 2 the area of the end of the girder. [bridging joists. 2f. 3in sum of the areas of the ends of the girder and 20 0 common length. 45f. O the solidity of the girder and bridging joists. i. ii. 17f. 0 0 solidity of all the binding joists. 5i 24 2 6ii 41 Continued. 10ii Oiii area of the end of a ceiling joist. 6 O solidity of a ceiling joist. number of ceiling joists. O solidity of all the ceiling joists. 17 0 45 0 72 0 sum of all the solidities in the whole floor. PROBLEM III. To measure roofing or partitions, either for materials or workmanship. All timbers in a roof or partition, are measured in the same manner as floors, excepting king-posts, queen-posts, &c. when there is a necessity of cutting out parallel pieces of wood from their sides, in order that the ends of the braces that come against them, may have, what is called by workmen, a square butment. To measure the workmanship of such pieces, or posts, take their breadth and depth at the widest part, and that multiplied by the length, will be the solidity for workmanship. To find the quantity of materials, if the pieces sawn out are 2 inches thick, or more, they are esteemed pieces of timber fit for use; when more than 2 feet long, their lengths should not be esteemed so long by 5 or 6 inches, because the saw cannot enter the wood with much less waste, and consequently the pieces must be deducted deducted from the whole solidity, and the remainder will give the quantity of materials: but if the pieces cut out are less than 2 inches, then the whole post is measured as solid for the materials, because the pieces cut out are but little use. EXAMPLE. Plate 57, Fig. 4, let the tie-beam D be 36ft. long, 9in. wide, by 1ft. 2in. deep; the king-post, marked A, is 11ft. 6in. high, 1ft. broad at the bottom, by 5in. thick: out of this are sawn two pieces from the sides, 3in. thick, and 7ft. long; the braces, marked B, B, are 7ft. 6in. long, 5in. by 5in.; the rafters, marked D, D, are 19ft. long, 10in. by 5in. each; the struts, marked C, C, are 3ft. 6in. long, and 4in. by 5in; required the measurement for workmanship, and also for materials. |
