I ain't no genious, but my figures don't match nobodies here. But at least I'm gonna show my work!
The quarter inch spacing requirement can be added to each of the bricks dimensions.
Therefore, each brick formally having the dimensions 3 inches x 6 inches will have an extra 1/8 inch on each side. This translates to a virtual brick size of 3.25 inches x 6.25 inches
One way to calculate the approximate number of bricks is simply to divide the surface area of an individual brick into the total surface area. The astute observer, however, will realize that on the perimeter, the brick calculation will require an extra 1/8 of an inch along the entire perimeter because we assumed this with the -virtual- brick size.
A way around this approximation is to *assume* that the perimeter is actually 2x (30ft. + 1/8 in.)+ 2x(100ft.+1/8 in.) to allow for this virtual brick. By doing this, we can avoid algebra.
Therefore the total virtual area is:
(100 ft. x 12 in./ft. + .125 in.)
x(30 ft. x 12 in./ft. + .125 in.)
= 432,195 inches squared.
Now given that the virtual brick size is:
3.25 in. x 6.25 in. = 20.3125 inches squared.,
the total number of bricks needed is:
432,195/20.3125 = 21277.29231
or 21278 bricks
Buck
