Updated: Nov 24, 2020
Ed is a do-it-yourselfer who is happy to share some of his ideas and experiences in this monthly column.
Many windows in older homes are “double hung” types that open up and down, with counterweights helping to hold things in place if partially opened. That is, unless 1) they’ve been painted over so many times that they won’t open, period (paint works like super glue!) or 2) the ropes are broken and no longer attached to the weights. This write-up addresses issue 2. Sometimes, in the course of painting, the ropes have been painted, making them stiff and more likely to get clogged in the pulley. It’s also possible that you have sash CHAINS instead of rope. Those are less likely to break, I think, but they still do. If you have chains, you’ll need to adapt the following somewhat.
This month, we’ll be replacing the rope on an inner window. The outer ones work the same way, but are more difficult to access because of the thin strip of wood that separates the inner and outer, since it needs to be removed to get the outer window out of its channel. Here’s a picture of the typical scenario of the broken sash cord:
The first step is to (carefully) pry off the molding at the front edge/sides of the window. There are likely 4 or 5 finishing nails that hold it in place (more on an option later). TIP: Once you pry the molding off, use good pliers to grab/twist and pull the nail through the molding (the back side) rather than push it out through the front face. There will be a lot less damage to the molding, and a nail hole is very easily filled in with a dab of joint compound (you did read last month’s tip on using joint compound, didn’t you?). If you’re replacing just one rope, you only need to remove that side, but if the ropes are old and brittle, you should go ahead and replace both sides anyway.
By the way, the old carpenters are famous for making everything fit precisely. To actually get the molding out of the window frame, it’s usually necessary to “bow” it in the middle, rather substantially. If you don’t do that it’s likely you’ll scratch up the sill where it’s a flush cut on the molding. The top will be mitered, so you’ll need to pull the bottom toward the center of the window after making the bow in the wood, which essentially decreases its length to facilitate removal.
Here’s a picture of one side molding removed:
Then you may need to raise the window up enough to see the weatherstrip. It’s likely a metal piece nailed in place with small-headed, short nails. You should carefully pry/pull them out, trying to avoid doing damage to the metal strip. It will only be nailed at the front edge. Once the nails are out, you can pull that edge of the window away from the frame. The metal strip will come forward and out with the window. You can just pull the window itself away from the other side. Be careful, though, because if the other side has a rope still attached, you will need to pull the knot at the end of the rope out of the socket in the window edge and carefully lower the weight.
Here are the nails, and the strip after removal:
Getting that strip out of the way should expose a “trap door” of sorts, usually held in place by 2 screws, one at the top and another at the bottom. It may take some prying to get the cover popped out from its recess. The back edge will be under the wood, so pry from the front.
Then you can reach in, pull out the weight that’s not attached and functioning, and cut any rope remnants off of it. It’s likely to be quite dirty in there, so be forewarned!
Buy some good quality sash cord of a diameter just right to fit onto the pulley at the top. Too large and it won’t fit, and too small and it might come off the pulley and jam in the slot. Then you’ll need to “fish” the sash cord through (over) the pulley, and down into the trap door cavity. In these pictures, I used a small length of twine with a nail on it as a weight, and dropped it in over the pulley, letting gravity take it to the opening. Then I tied the sash cord onto the twine and pulled a length of it through the pulley and down.
Tie the end of the rope onto the weight. The old-timers used a funky knot that I can’t figure out, but I like a “bowline” knot. Look it up if you’re not a Boy Scout and familiar with such things. Now the tricky part is to make a couple half-hitches at the top of the rope. The knot should be located about 2 inches down from the pulley after being tied, so give yourself some extra slack, and then cut it to length after the knot is located and well-tied. The goal here is to make a “clump” of knot large enough to fit tightly into the recess in the window edge. Usually it’s just a pressed-in fit, but sometimes folks insert a nail or a screw into things to help hold the knot in place.
Putting the trap-door back into place is sometimes harder than it should be. TIP: I like to cut a chamfer on the inside edge of the door so that it slips into place more easily. Don’t cut so much that the bevel extends all the way to the front, or you’ll be leaving a big gap that will let cold air through.
Re-install the trap door. If you’re replacing just one rope, the metal weatherstrip will still be in place on the other side. If you’re doing both, re-install one weatherstrip (either side) and nail it in place. The picture below shows the left side of my window with the weatherstrip nailed in place, and my work will now be on the right side.
Now comes the part where some extra hands come in handy! It’s possible to do all this by yourself (I do it all the time), but it’s certainly easier with two people. Pull the upper knot down and while holding the window up, firmly tuck the knot into its recess on the window edge. A push with a dowel and a hammer tap isn’t out of the question. Then push that edge of the window onto its weatherstrip (the one firmly attached). Then you can pull the other knot down, lifting its weight/counterbalance, and push it into the other side recess. Once that’s done, slip the metal weatherstrip onto the exposed window edge and push the whole assembly into place. Leave a bit of the weatherstrip exposed below the window, as you’ll need to be able to grab it and pull/push it into position. Here’s the right edge of my window (left edge already snapped onto the weatherstrip), with the right-side rope knot pushed into the recess, and the weatherstrip slipped into place, ready to push the window into position.
Once you push it into the right spot, re-nail the metal weatherstrip at its front edge. You’ll need to slip it up/down a bit. It’s a good idea to test everything before getting too carried away with lots of nails. Be sure the window slips up and down easily, that the ropes aren’t binding in the pulleys, and that the counterweights are doing their job to help hold the window at any position. If things fit but seem snug, a bit of spray lube onto the metal weatherstrips usually helps.
Now, all that’s left is to re-attach the front moldings. You’ll need to bow them again to get them into place, first inserting the top into the miter, then pulling the middle away from the frame while inserting the bottom. Locate them to make a nice fit to the window without needless rubbing against everything. Test fit by lifting and closing the window. I like to avoid nailing the moldings back into place, and prefer using nice brass screws and brass cup washers. It gives a rich, professional, antique appearance, and makes any future removal much easier. Here’s a pic of the final product, showing this option. I think 3 screws per side on a normal window, or 4 per side for larger windows, looks about right. Measure and space them the same on both sides of all your windows.