Can not open up completely, unlike double casement windows as there is normally the scale of one sash more than the window.  Draught proofing pile is low drag and lessens friction, What this means is the sash will travel efficiently, and make the sash considerably much easier to open and https://bedroom-light-fixtures93589.pages10.com/a-secret-weapon-for-sash-window-draught-proofing-71386732