[PROBLEMS IN ESTIMATING QUANTITIES]
Brick Problem
To find the number of standard size brick, face and common, laid in a sixth course Common Bond with a 3/8-inch joint, for an 8-inch gable wall, 25 feet wide and 18 feet high from grade to eaves and thence to ridgepole 12 feet. The 12-inch basement wall is 71/2 feet high, 4% feet being below grade. There are 4 windows each requiring an opening of 3'-6" × 5'-2" and 1 window requiring an opening of 2'-6" × 4'-2". See window sizes [page 22]. The basement windows being less than 10 square feet are disregarded.
Face Brick
| First find the area in sq. ft. for face brick: | |
| Rectangle of wall 18' × 25' = | 450 sq. ft. |
| Gable triangle 12' × 25' = 300 - 2 = | 150 sq. ft. |
| Total area | 600 sq. ft. |
| Deduct the 5 window openings, thus: | |
| 4 × 3'-6" × 5'-2" = 721/3 sq. ft. | |
| 1 × 2'-6" × 4'-2" = 105/12 sq. ft. | |
| Window openings to be deducted | 83 sq. ft. |
| Total area to be covered with face brick | 517 sq. ft. |
| By Table 1, it takes 6.5 standard size face brick per sq. ft. for Running | |
| Bond with a 3/8" joint. | |
| Hence, 517 × 6.5 = | 3,360 |
| Add 162/3% as per Table 2 | 560 |
| Number of face brick required | 3,920 |
| Total of face brick to be ordered | 4,000 |
Common Brick
| The common brick backing takes the same number as face brick, except that we deduct the 162/3% added to the face brick quantity as per Table 2. Hence, the number of common brick for backing is 3,360 - 560 = | 2,800 |
| As the wall from grade to first floor is three brick thick, the same as the foundation wall, it requires two tiers of common brick and, therefore, an additional tier must be figured in. Hence, 25' × 3' or 75 sq. ft. at 6.5 per sq. ft. = | 488 |
| The 4'-6" of foundation wall, being three brick thick, gives us 25' × 4'-6" × 3 or 388 sq. ft. to figure on. Hence, common brick for foundation is 388 × 6.5 = | 2,197 |
| Total common brick required | 5,485 |
| Total common brick to be ordered | 5,500 |
Hollow Tile Problem
By referring to [pages 25 and 26], it will be seen that four courses of brick with a 3/8-inch joint equal in height two 5" × 12" tile, so that, in our present example, if we wish to use the 3/8-inch joint, we shall have to introduce our bonding course of brick every fifth instead of every sixth course. This would also naturally involve a slight change in the number of face brick required. That is, instead of adding 162/3% or we should have to add 20% or 1/5 to the number required for Running Bond, in order to get the right number for fifth course Common Bond and, in consequence, we subtract 20% or one fifth from the backing tile wanted. With these changes understood, our problem for a hollow tile backing for the gable wall will work out as follows:
If the hollow tile backing is started at grade, the tile and face brick area will be the same. But as, in the present case, we start the tile backing from the first floor, we subtract the area of the wall from grade to first floor or 25' × 3' = 75', and get 517 - 75 or 442 sq. ft. to be backed with tile.