Fig. 4
For example, the number of studs required for partitions only, shown on the plan, [Fig. 4], is computed in the following manner.
- 30 ft. 6 in.
- 10 ft. 6 in.
- 9 ft. 6 in.
- 5 ft. 0 in.
- 4 ft. 6 in.
- 60 ft. 0 in.
Deducting one-quarter from 60 feet, the remainder is 45 feet; adding 1 stud, the result is 46 feet. As there are 4 returns, with 2 studs for each, as shown at a a, the total number is 46 + (4 × 2) = 54 studs.
As a general rule, when (as is customary) the studs are set at 16-inch centers, 1 stud for each foot in length of partition will be a sufficient allowance to include sills, plates, and double studs. Thus, if the total length of partitions is 75 feet, 75 studs will be sufficient for sills, double studs, etc. If the studs are set at 12-inch centers, the number required will be equal to the number of feet in length of partition plus one-fourth. Thus, if the length of partitions is 72 feet, 72 + 18, or 90, studs will include those required for sills, plates, etc.
The same rules may be used for calculating the number of joists, rafters, tie-beams, etc.
A good way to estimate bridging is to allow 3 cents apiece, or 6 cents per pair; this will be sufficient to furnish and set a pair made of 2" × 3" spruce or hemlock stuff.
46. Sheathing.—To calculate sheathing or rough flooring (not matched), find the number of feet B. M. required to cover the surface, making no deductions for door or window openings, because what is gained in openings is lost in waste. If the sheathing is laid horizontally, only the actual measurement is necessary; but if it is laid diagonally, add 8 or 10 per cent. to the actual area.
47. Flooring.—In estimating matched flooring, a square foot of ⅞-inch stuff is considered to be 1 foot B. M. If the flooring is 3 inches or more in width, add one-quarter to the actual number of board feet, to allow for waste of material in forming the tongue and groove; if less than 3 inches wide, add one-third. Flooring of 1⅛-inch finished thickness is considered to be 1¼ inches thick, and for calculating it the following rule may be used: Increase the surface measure 50 per cent. (This consists of 25 per cent. for extra thickness over I inch, and 25 per cent. for waste in tonguing and grooving.) To this amount add 5 per cent. for waste in handling and fitting.
In figuring the area of floors, openings for stairs, fireplaces, etc. should be deducted.