If your house has old wood windows that slam shut, they are probably missing the weights. Weights were used for many years to counterbalance the sash and hold the window open. They’re connected to cords that attach to the edges of the sash. The cords can break, but luckily they’re designed to be easily fixed.

On most windows, you can get to the weights through access panels located on the side jambs (Illustration). To reach the panels, you first have to remove the sash and the stops that hold the sash in place. Use a utility knife if necessary to cut through the paint or finish where the inner stops meet the jambs, and carefully pry the stops free. This allows access to the weights for both the upper and lower sash.
Remove the sash from the jamb. Now you can get to the access panels. Remove the screw holding the panel, pull it out, and take out the weight.
Then cut a new sash cord using the old, broken one as a guide for the length. Fish the cord over the pulley, and tie it to the weight. Finally, knot the other end, and attach it to the edge of the window sash.
Have a nice weekend,
Wyatt Myers
Online Editor, Workbench