Care should be taken to order panels of the correct length to avoid having to take corrective measures after purchase. Panel lengths should fall 2 to 3 inches short of the ridge when a vented ridge is desired, and should extend 2 to 3 inches past the eave to allow a sufficient drip edge (except as noted on pg. 3 concerning gutters). When a roof transition is involved, panels of the upper portion should be ordered short to allow placement of the transition flashing.