Construction kit for horizontally and vertically sliding window assemblies

A meeting rail for a construction kit for horizontally and vertically sliding window assemblies, comprising:

• a substantially L-shaped profile having first and second legs which respectively include an inner and an outer surface;
• the first leg of the meeting rail being affixable to an edge of a window sash of the window assembly so that the inner surface thereof overlies the edge of the window sash;
• and
• the second leg of the meeting rail including means for retaining a weatherstrip on each of the outer surface and the inner surface thereof, said means for retaining the weatherstrip being in opposed relationship on the inner and outer surfaces, a length of weatherstrip longer than the second leg outer surface and engaged by said means for retaining a weatherstrip on the outer surface, said length of weatherstrip extending beyond at least one end of the second leg and wrapped around said end and engaged by the means for retaining the weatherstrip on the inner surface, thereby providing an improved seal between the end of the second leg of the meeting rail and an adjacent frame surface of a window assembly.