Window sill insertion problem in General Discussion Posted October 13, 2014 · Edited October 13, 2014 by Joe-SA Extending the conversation on #4 above... Not only does the bottom of the frame create a bump in the sill but the lower trim does not shift down when a timber sill is selected and creates a similar bump in the sill along the plane of the casings. When trim below the sill is checked on it should be BELOW the sill and not sharing the same space. Nor does the side trim extend down to the top of the Sill Lip. It stays the same length as if a picture frame trim was intended. When a sloped timber sill is used the side casings must extend down the height of the Sill to meet it and avoid leaving a gap. 9.) The exterior trim on clad units butt up against the projected jambs and do not partially cap the jambs as this tool as always shown. Its a minor technicality but the final width of the unit from the outside edge of casing is always slightly narrower then what will be built. Increasing the width of the casing is not an acceptable work around. 10) The width of the Head Trim should be independent setting from Side Trim. It would be nice if this was true for the Lower Trim as well.