Windows

A box sash runs between the pulley stiles of its frame, separated by the parting bead and held on the inside by the staff bead, with cords running over pulleys to weights inside the sash boxes. Paint stiffens cords and shortens their life, and build-up on the running surfaces makes sashes bind, so cords are kept clean and those surfaces thin. Sashes painted shut are cut free and eased. We reverse the sashes to paint the lower part of the top sash and its meeting rail, return them to paint the rest, finish with the frame, beads and sill, and move them while the paint dries.

Cracked or loose putty is cut out and replaced. Traditional linseed oil putty needs to form a skin before it is painted — typically a week or two, depending on the product and weather, as the manufacturer’s guidance sets out. The paint is taken just onto the glass, by a millimetre or two, to seal the joint between putty and glass. Old glass is handled gently, and cracked panes are left to a glazier.

Timber casements need the same care at their hinges and opening edges, and draught-proofing strips are masked rather than painted. Steel windows, common in houses of the 1930s, are taken back to sound metal where rust has started and primed with a metal primer. Older windows are discussed further under period properties.