Three-layer systems: First layer- 1 in. long for
1/2 in, 5/8 in. thick panels, spaced 24 in. OC. Second layer- 1-5/8 in. long
for 1/2 in., 5/8 in. thick panels, spaced 24 in. OC. Third layer- 2-1/4 in.
long for 1/2 in. thick panels or 2-5/8 in. long for 5/8 in. thick panels,
spaced 12 in. OC. Screws offset min 6 in. form layer below.
Four-layer systems: First layer- 1 in. long for
1/2 in., 5/8 in. thick panels, spaced 24 in. OC. Second layer- 1-5/8 in. long
for 1/2 in., 5/8 in. thick panels spaced 24 in. OC. Third layer- 2-1/4 in.
long for 1/2 in. thick panels or 2-5/8 in. long for 5/8 in. thick panels,
spaced 24 in. OC. Fourth layer- 2-5/8 in. long for 1/2 in. thick panels or 3
in. long for 5/8 in. thick panels, spaced 12 in. OC. Screws offset min 6 in.
from layer below.