The operating cords in conventional, timber-framed sliding sash windows will eventually need to be replaced for anyone who owns or resides in a home with these windows.
The basic design has hardly changed in the three centuries that they have been a part of our built environment.
As a carpenter, I specialized in fixing and maintaining a wide variety of sliding sash windows from the Georgian, Victorian, and Edwardian eras. Now is the moment to share what I’ve learned from experience.
Due to modern plastic and aluminum windows’ widespread availability, I fear these techniques may be lost over time. Thus, the best way I can preserve them is to document them in writing for future generations.
However, the fundamental instructions for replacing the cables that suspend the balance weights have not altered significantly in a very long time.
Sash windows have molded timber beads (staff beads) at the top, bottom, and sides to keep the movable sashes or frames in place within the box frame. They are usually nailed or pinned, although occasionally screwed, to the window’s box frame. For a smoother, more aesthetically pleasing result, the holes created by the nails or pins are typically filled and painted over to conceal them.
The cables and weights can’t be accessed until the side staff beads are removed. Even though it is possible to replace the top sash cords without removing either staff bead, I find it far more convenient to do so and would recommend that others who are less skilled do the same.
The target audience for these guidelines consists of amateurs who have some familiarity with essential carpentry tools.
Use an old wood chisel; the more comprehensive, the better, and you don’t mind damaging the edge off by hitting concealed nails, which will inevitably be encountered when removing a staff bead.
Using a regular hammer, drive the chisel firmly into the groove between the staff bead and the box frame. Take the bead and lever it away from the box. The staff bead should be worked on multiple times, from top to bottom. Once the dot loosens, it can be quickly sprung away from the box frame. Move on to the other bead on the staff and do the same thing.
The next step is to remove the bottom sash frame from the box frame after cutting any existing cords and ensuring all nails have been removed from the window frame.
To remove old cords from the sashes, pull the weights to their maximum position, hold the line tightly, and cut it away from the belt with a sharp pair of side cutters; then, carefully lower the weight as close to the bottom of the frame as possible before releasing it. If dropped carelessly, more significant consequences can harm the structure or fall into the wall hollow, making removal extremely difficult.
Then, untie the sashes and mentally note how the old cord was secured so that you can put the new line in the same position.
The lower sash on the interior of the box frame can now be taken out entirely.
A thin strip, running top to bottom and fixed in an eight mm groove, now separates the two sash frames and helps to draught-proof the window on each side of the box frame. These are the separating beads, and they should fit snuggly into the slots.
With a more precise wood chisel, pry them loose from the slots. Running a sharp Stanley knife down each side of the beads to break the seal of the paint can make this process easier and safer for the dots.
Removing these beads will release the outer sash frame, allowing the sash to be detached from the frame without cutting any cords. When you unhook the weights, remember to lower them slowly and carefully, as you did before.
It’s a good idea to clear the area around the box frame so you can work on it without worrying about breaking the glass in the sash frames. I dropped Many shattered windows from hammers and other equipment from the window sill. Expensive, time-consuming, and irritating.
Now that the sash window box frame is empty, you can see the pockets, or cutouts, on either side. Depending on the window’s state, these may be loose and apparent or well-fitted and concealed by paint. They can be found and eliminated with relative ease in any case. It is helpful to assign a number to each of the windows in a room before beginning to replace them.
The iron or lead weights can be removed when these compartments are eliminated. Take note of the location of any varying weights. The more extensive bottom rail of the inner frame necessitates that the rear consequences be more significant than the front ones. The weights must be returned to their proper locations to keep the sashes operating smoothly.
It’s time to clean the box frame before installing new cords and reassembling the weights and pockets. Now is the perfect moment to make any necessary fixes or start any desired upgrades. While the window is apart, fixing or replacing broken glass or putty and repairing any damage to the wood is much simpler.
Additional draught-proofing seals, new locks, and a fresh coat of paint are all good ideas to consider while you’re at it.
Mouse’, an essential homemade tool for replacing cords, consists of a solid thread length (about 2 meters) or a thin line with a small piece of lead affixed to one end. This must be on the small side to fit through the opening at the top of the box frame’s pulleys.
Insert the mouse into the front pulley’s gap and let it drop into the box; then, secure a fresh cord length to the other end of the string. To hang the eight inside the frame, find the mouse through the pocket, gently pull the rope over the pulley, and the new cord down to the bag. From there, you can reattach the iron weight to the new line and pull the weight to the top of the frame. You should do this with each of the four ropes and weights.
When the weight is dangling from the uppermost part of the frame, the new rope should be long enough to extend approximately halfway down the length of the pocket. There should be enough string to thread through the frame and tie a knot on the side. (Depending on the sash’s design or current condition, you may need to screw or nail the cable to the frame.) Panel pins through the rope and into the box frame are my go-to for keeping the load suspended at the top. You may re-attach the cord to the sides of the sash frame without using your hands.
Cords should be long enough to lower the front sash frame such that the top rail is about halfway down and the bottom rail does not quite reach the outer sill when reattached. This requires some trial and error but becomes more straightforward with experience.
The two pockets can now be reinstalled with the best possible flushness to the frame. Panel pins may be required to protect them from interfering with the sash frames if they are too loose.
Finally, insert the separation beads back into their grooves and fix them with panel pins if necessary. Beads that are broken or starting to decay should probably be replaced. This may be found at any home improvement store and even at certain hardware stores. However, you may need to reduce your beads’ thickness by a few millimeters if you use current beads instead of the original beads.
You can replace the inner or bottom sash frame once you’ve double-checked that the meeting rail is level and the window catch is aligned.
The final step is to reinstall the staff beads, providing some wiggle room for the sash frames but preventing rattles and other noises when the windows are open in windy conditions. Drive the pins only halfway into the panel to start, and then use three or four 40 mm panel pins to fasten the beads. Drive the pin home once you have inserted a piece of cardstock, an old credit, or trade card between the sash frame and the dot to get the desired gap. Mission accomplished.
If this is your first time switching cords and everything functions as it should, you should feel accomplished and proud of yourself. You’ll have saved some cash, too!
Read also: Safety Precautions For Implosion Of Glass Under Vacuum
