There are weights hidden either side of your sash windows – the weights are normally made from lead or cast iron and they are hung on cords that allow the windows to counter-balance, using a pulley wheel at the top of each window frame. If the cord snaps, the sash needs to be removed from the frame for the cords to be replaced and this is a service we offer. We use the best quality waxed cord, which will last years and cord replacement forms part of our window refurbishment service.