Replacing a broken sash cord

1 Remove the staff bead – this is usually nailed to the window frame. Begin in the middle alongside a nail and use a wide chisel to prise the bead away from the frame. Bend the bead outwards at the same time as freeing the other nails. Use pincers to remove all the old nails from the frame and beading.

2 Removing the bead from just one side should allow the sash to be lifted out of the frame. Once the window is dismantled it makes sense to replace both cords. If the cord is worn yet not broken, pull it down towards you so the weights are raised to the top and sever with a craft knife. Tie a knot at the end and gently lower the weight. The knot will stop the weight from falling down.

3 The cord is normally tacked onto the side of the sash. Remove the old cord with pincers. Repeat the procedure to replace the other sash cord. If the upper sash has not been opened for a long time do not assume that the cords are intact. For safety’s sake, in case it should drop down unexpectedly, knock a nail into each side of the frame just below the upper sash.

4 Remove the parting bead by pushing a chisel between the frame and bead and prising it free. Start at a nail about halfway down the length and ease the nails out in unison. When removing beads it’s important to take your time to avoid splitting the wood. Initially run the corner of a scraper down the edge to break the paint seal; and ease rather than force the nails out.

5 Locate the sash weight pockets on each side of the jamb. They often lie obscured beneath layers of paint. Run a craft knife around the edges to break the paint bond. Ease the covers up and out. Untie the knotted cords and lower the weights. Then pull the weights through the pockets.

6 Using the old sash window cords as a guide, measure out and cut two generous lengths of new waxed cords. Tie a small heavy object, such as a nut, to the end of one of the cords and carefully feed it down through the pulley vent and out of the pocket.

7 Pass the first couple of inches through the weight and tie a knot. Return the weight to the pocket to one side of the parting strip (a length of free-hanging wood secured at the top). Pull the weight up to about four inches below the pulley. Rest the sash on the sill and tack the cord into the groove in the sash stile. Trim the excess cord. Repeat on the other side.

8 Reassemble the window and return the parting beads and staff beads to their original positions. We then painted the window with traditional linseed paint, which will protect the wood and keep the window looking good for years to come. It’s also kind to the environment as it doesn’t contain solvents and is made from renewable and sustainable ingredients.