The Woodgrain Millwork 1-1/4 x 4-3/4 x 96". Primed Finger-Jointed Pine WG S2 Sill is used on exterior windows to help channel water from the window to the outside of the house. Primed Finger-Jointed Pine WG S2 Sill can be used to replace damaged sills on existing windows. Sill moulding is important part of keeping your house safe from water.