How to fix double-hung sash windows with broken ropes

A primer.

Broken sash cords can be easily repaired with an understanding of how double-hung sash windows are constructed, a few simple tools and patience. One of the good things about traditional wooden double-hung sash windows is that they are repairable using materials that can be found at any hardware store.


Double-hung sash windows are held in place on the inside with window stops. If the stops are secured by screws and finish washers, remove the screws to take out the stops. If the stops have been painted in, they need to be cut free with a utility knife. If they are secured by nails, the stops need to be gently pried free, taking care not to damage the stop. Finish nails should be pulled through with a pliers rather than pounded back.


Once the stops have been removed, the lower sash window should be free to be taken out. If one rope is still attached to the window, it is usually held in place with a nail through a knot. This is easily pulled out.


In the lower part of the window channel, there is an opening to the weight chamber that is usually accessed by removing a screw. The weight can be pulled out of the chamber, and will most likely have the end of the broken rope still attached to it. Before you remove the rope, note how the knot is tied. You can use this knot as your guide in tying a new knot.


Make sure you use the appropriate size sash cord. Do not use nylon rope, as it will stretch, and the counter-weighs won't work anymore. Feed the rope through the pulley at the top of the channel. Use a coat hanger if necessary to help you fish the line through the weight door. Tie the rope to the weight and return it to the chamber. The knot needs to be one that tightens when it pulls, such as bowline knot.


Raise the weight to its highest point and the window to its lowest point to determine the correct length for the cord. Make sure there is enough length for tying a knot at the end of the rope. The knot goes into the hole that is one third from the top of the sash. Secure it in place with a short nail. Replace the window stop.


If the window has old style interlocking weatherstripping, the process is more complicated. Weatherstripping can be difficult to remove without damaging it; be careful and gentle. Resist the temptation to tear it out and not reinstall. That weatherstripping is saving you heating and cooling dollars.


Many people are unaware that their upper sash windows are designed to be moved. In working order, the upper and lower sashes can reverse positions: the upper one down and the lower one up. In the days of large, window-sized screens, the upper and lower sashes could both be opened, to create a cross current. Modern combinations are glass at the top, and the reasons for lowing the upper sash have dwindled. It is a rare house, however, where you can find the upper sash not frozen in place by paint, age, coal dust, and broken ropes.


To repair a rope on the upper sash, it is necessary to remove the parting stop, which is a rectangular molding between the upper and lower sash. Like weatherstripping, this parting stop is often both fragile and difficult to remove. I should probably note that one can only access the parting stop and the upper sash when the lower sash has been removed. The process of replacing the rope on the upper sash is the same as for the lower sash.


While you have the sash windows open, this would be a perfect time to clean out the channels and scrape out accumulated paint. Before the sash windows are put back in place, they can be rubbed with a beeswax candle to aid in the free movement for the window. Things that work make your life work.