C – Parting bead. There are two parting beads positioned on each side of your sash box, running vertically from top to base amongst the sashes. Each individual half portion of the Ventrolla parting bead incorporates a draught-proofing procedure that faces the adjacent sash, forming a comfortable weather seal.  E – Bottom sash. This refers https://contemporaryceilinglights54948.blogoscience.com/42179395/sash-window-draught-proofing-an-overview