F Wave requires the use of ribbed valley metal flashings on all valleys. For a closed valley look, use a single rib flashing and bring shingles to each side of the center rib. For an open valley, use a 3 rib flashing, bringing the shingles to each of the outer ribs.
You may cut valley shingles as you go, or apply a chalk line at the outer edge of the appropriate rib after all courses are laid. Remember, blue chalk only.
Ensure the edges of the valley shingles are cut straight to provide a clean and professional look. Place 2 beads of F Wave-approved sealant under the cut edge of each shingle, and cut a 1”, 45° angle piece, or “dog ear” from the top of each valley shingle to prevent water from traveling laterally across the shingle. Use this same procedure on all rake edges and sidewalls.
Dormer Valley Terminations should carry the valley flashing past the transition ensuring that no water reaches the difficult to flash areas and is directed away from the sidewall.