Abstract: A modular sub-sill unit to provide improved water drainage is attachable to a bottom part of a sill and to a portion of an exterior wall that corresponds to the bottom of an opening, such as a door, window, or skylight. The sub-sill unit may include a top plate, which provides a plurality of weep holes that allow liquid to pass through and be deposited on an inner deflection wall. The inner deflection wall deflects the liquid into a water trough or channel, which extends across the length of the sub-sill unit at a front edge facing outwardly from the exterior wall. The liquid then exits through a plurality of exit holes in the outer front edge. The inner deflection wall thus creates a dry zone that prevents the liquid from reaching a base plate and protects the fasteners that attach the base plate to the exterior wall.

Abstract: An improved window sill system has a modular bottom sub-sill unit to be attached to a bottom part of a window unit and mounted to a bottom frame part of a window frame in an opening in an exterior wall of a building in order to provide improved water drainage for the window sill system. The bottom sub-sill unit has a water trough or channel extending across its length at a front edge facing outwardly of a window unit to which the sub-sill unit is mounted. The water trough or channel has a top plate provided with a plurality of weep holes for capturing rainwater dripping down the window into the water trough or channel. A base plate is provided for mounting the bottom sub-sill unit with fastener screws to the bottom frame part of the window frame. An inner deflection wall deflects water from the weep holes into the water trough or channel to prevent water from reaching the fastener screws in a dry zone below the inner deflection wall.

Abstract: An improved window sill system has a modular bottom sub-sill unit to be attached to a bottom part of a window unit and mounted to a bottom frame part of a window frame in an opening in an exterior wall of a building in order to provide improved water drainage for the window sill system. The bottom sub-sill unit has a water trough or channel extending across its length at a front edge facing outwardly of a window unit to which the sub-sill unit is mounted. The water trough or channel has a top plate provided with a plurality of weep holes for capturing rainwater dripping down the window into the water trough or channel. A base plate is provided for mounting the bottom sub-sill unit with fastener screws to the bottom frame part of the window frame. An inner deflection wall deflects water from the weep holes into the water trough or channel to prevent water from reaching the fastener screws in a dry zone below the inner deflection wall.

Abstract: An improved window sill system has a bottom frame structure that is part of a sill frame unit. The bottom frame has a water trough or channel extending across its length at a front edge facing outwardly of a window in which the sill system is to be installed. The water trough or channel has a top plate provided with a plurality of weep holes for capturing rainwater dripping down the window into the water trough or channel. A base plate is provided with screw holes for mounting the bottom frame to a surrounding window frame. An inner deflection wall deflects water captured in the water trough or channel from the screw holes for mounting the bottom frame of the sill system to the window frame.