A traditional pair of sash windows make a great match for older properties – and some newer ones, too.  They incorporate one or more movable panels (or ‘sashes’) which can be slid up and down to open and close the window.  These panels are counter-balanced by weights, which hang on cords concealed by the window frame.  What happens when one of these cords snaps?  The sash gets stuck.

Replacing these cords can be a little fiddly, and so once you’ve got the window open, you’ll want to swap them all at the same time.  And, while you’re at it, you might as well install insulation brush strips around the sashes.  Brushes will keep those pesky draughts at bay and safeguard the overall performance of your window.

Let’s consider how the job might be done.

1.      Assemble your tools

Before getting started, you’ll want to be sure you’ve a few items to hand.  These include:

  • A filling knife
  • A flat-head screwdriver
  • A volunteer
  • Some nails
  • A hammer
  • New cords. Waxed cotton is best: it’ll move smoothly and will last for ages.

2.      Remove the sashes

From the inside of the building, prise the beading from the frame using either a knife or flat-head screwdriver.  You’ll then be able to lift out the inner sash and see into the compartments that house the weights.

The covers will flip open with a little encouragement from your screwdriver – but if they’ve been painted over, you’ll need to cut them out.  Between the two sashes is another layer of beading.  Remove it in the same way and free the sash.

3.      Remove the old cord

Having disassembled the window, you’ll be able to remove the old cords.  Before attempting this, cut the weights off the end using scissors.  Having freed the cord, you’ll be able to easily pull it out.

4.      Install the replacement cord into the outer sash

Get your volunteer to hold one end of the new cord, and then feed it over the pulley beside the outer sash channel.  Once you’ve pushed it around, you’ll see it dangle on the other side.  Pull it down and tie it securely to the weight.  Now repeat the procedure on the other side.

For the cord to be the right length, the outer sash should be a few inches above the windowsill when the top of the weight hits the pulley.  Get your volunteer to hold it in position and then pull the cord until you hear the weight impact the pulley. Then, secure the cord into the cord grove using a nail.  Trim away any excess and then replace the central beading.

5.      Install the replacement cord into the inner sash

Next, you’ll want to install your replacement cord into the inner sash.  Attach the new cord with nails in the same way.  This time, the cord is the right length if the weight is at the top of the channel when the sash is all the way down.

6.      Put everything back together

Your final task is to reassemble the window.  Replace the weight covers first, tapping them into place with your hammer.  Then, replace the sashes and the beading.  If any have been damaged during removal, they’re inexpensive and widely available.  Check everything’s working properly, and apply a coat of paint if you feel it necessary.

Looking for new windows for your home? Browse our sliding sash or conservation windows or find out about our handmade bespoke windows.

Want to learn more about sash windows? Check out our other posts:

How to Paint a Sash Window (without it sticking)

Sash Windows: uPVC or Timber?

How to Fix a Sash Window that Won’t Stay Open