Grip-Rite™ Eave & Valley Protector provides additional protection against roof damage caused by ice and water. Install beneath shingles, along with areas where water may collect such as around chimneys, valleys, vents, skylights, or other similar areas. Without proper drainage, water can accumulate and form ice dams, which cause more water to stay on the roof. Moisture on a roof can eventually work its way underneath the shingles to the roof deck and ultimately to the interior of the structure, causing additional damage.