In order to measure-cut window sills, you may use a circular hand saw with a sharp blade or a compass saw with dense teeth downstroke-cutting blade.
Measure-cut window sills are installed with assembly foam and distance markers.
The installation of window sills should be performed after the window has been mounted and the assembly foam from the installation has dried up. Many window types have an additional profile thinner than the frame under the window. The outer edge of the window sill is placed against the additional profile and the upper part is supported against the frame. The gap between the window sill and the wall below it is filled with assembly foam.
An aluminium foil tape may be glued beforehand onto the surface for vapour barrier if necessary.
In order to avoid the accumulation of dirt and dust in the joint between the window sill and the frame, it may be filled with silicone.
Mechanical blows against the window sill surface must be avoided upon installation.
Installation with materials containing moisture (e.g plaster mixture) is prohibited.
Water must be removed from the surface of the window sills immediately.