Step 5: Lid/Roof
Cut the 12' panel into four pieces, each 3' long by 2' wide. Then cut one of the 3' sections into 3 one-foot sections, and add a 1-foot section to each 2' piece: that makes three 3' roofs!
Make a "U" shape out of 2x2 that fits the size of the first bin: flush on the left side, and ending halfway onto the angled 2x4 that defines the pitch of the roof. Add an additional strip of wood to make a square out of the "U" (see photo).
Slap it together with screws, and attach it to the horizontal 2x4 at the top, using strap hinges.
Cut two identical strips of wiggle-board to fit the upper and lower edges of the roof, and tap in a few short screws to hold them in place. Fit the fiberglass onto the wiggle-board, overlapping as needed to make one 3' roof out of your 2' and 1' pieces. Secure all around with wood screws. If possible, use the self-tapping screws that come with their own pre-installed rubber washers, because those are extra cool and weatherproof.
Repeat for the other two lids, taking care that they all can open & close without bumping into each other.