Tru Mark receives a fair number of calls on subjects and products that generate some research and analysis. Recently a website visitor asked the question of how much sand do I need to topdress a football field?

First lets take some givens, 1.25 tons per cubic yard, topdress the midfield area of the high school football field between the hash with 1/8" of sand after the field has been core aerated. In most cases the midfield section of the football gets the most wear and tear and should receive the majority of the turf management resources versus looking at the whole field, especially from an expense standpoint. The cores are broken up using a drag mat and at the same time the sand is dragged back into the core holes. Two applications of sand and two drag mat passed may be in order to get the best results.

Now for some conversion of units to get apples to apples calculations:
1 cubic yard = 36" x 26" x 36" = 46,656 cubic inches
1.25 tons / 46,656 cubic inches = (1.25 x 2000)/46,656 = .0536 pounds/ cubic inch of sand
53'4" from sideline to hash mark so center area of the field is 160' - (53'4"x2) = 54' 4" x 300' = 16,300 sq ft. x 12 in. x 12 in. = 2,347,200 square inches
Sand needed for 1/8" application on the football midfield = .o536 lbs/cubic in. x 2,347,200 sq in. x 1/8 in. depth = 15,726 pounds = 7.86 tons = 6.3 cubic yards.

Do have a easier method for calculating the solution? If so please share.

1 cubic yard = 3" x 3" x 3" = 27 cubic feet
1.25 tons / 27 cubic feet = 92.6 pounds / cubic foot of sand
Depth in ft. = 1/96 ft ( 8x12)
Sand needed = 92.6 lbs. per cubic ft. x 16,300 sq. ft. x 1/96 ft. depth = 15,722 pounds