Multiply height by 1.5 (4 x 1.5 = 6) 6 rows

Multiply wall length by .75 (40 x .75 = 30) 30 blocks long

6 x 30 = 180 number of blocks needed ( 8" x 16" blocks )

3 bags of mortar per 100 block

Multiply wall length by .75 (40 x .75 = 30) 30 blocks long

6 x 30 = 180 number of blocks needed ( 8" x 16" blocks )

3 bags of mortar per 100 block