A broken sash cord means the window will not stay open, and it is one of the most common faults we fix. We remove the sash, fit new cord, check the weights and rebalance the window. Re-cording and counterbalance costs £120 per window, with a five-year guarantee on our labour.
How to tell a cord has broken
The signs are easy to spot. For example, the sash drops when you lift it, or it slams shut. You may hear a thud inside the frame. Sometimes the window feels light because the weight has come loose.
Do not force a window that has dropped, because a falling sash can crack glass or hurt fingers. Instead, prop it safely and call a specialist. Our guide to broken sash cord replacement explains what has gone wrong inside the frame.
A broken cord is also one of the signs your sash windows need repair. Often it is the first of several faults, because the strain that snapped it spreads.
Why cords fail
Cords wear because the window moves thousands of times over the years. First, they rub on pulleys and rot when damp gets in. Paint can also stiffen them, so they crack.
Age matters too. If one cord has snapped, its partner is usually close behind. For that reason, we normally renew both cords on a sash, and often every cord in the room.
What re-cording involves
The job sounds simple, but it needs care. Therefore each step below protects the joinery around it.
- We remove the staff bead and take out the lower sash.
- We open the pocket in the frame to reach the weights.
- We fit new cord over the pulleys and tie it to the weights.
- We check the weights match the sash, so it balances.
- We refit the sash and beads and test the window.
When we have the sashes out, we plane them so they fit the frame better. Therefore this cures many sticking windows with no extra step. The result is a sash that glides and stays put.
Weights and pulleys
A box sash hangs on cords that run over pulleys to cast iron weights. The weight must match the sash. If it is too light, the sash drifts down. However, if it is too heavy, the sash flies up.
We check this on every window. In addition, we check the pulleys turn freely. A seized pulley wears a new cord quickly, so we free or replace it. For more detail, read about how weighted and spring-balance sashes differ.
When an overhaul is the better choice
Re-cording alone is £120 per window. However, many windows with a broken cord also stick, rattle or leak air. In that case the sash window overhaul at £188 per window is better value.
An overhaul adds a draught-seal system, new timber profiles and new hardware. You pay a little more, but you fix several faults at once. Our draught proofing page explains the seals.
If the timber around the pulleys has rotted, you may need repair too. Our sash window repairs service covers rotten sills and rails. That said, we only replace what is needed.
What to expect on the day
We bring the cord, weights and beads we need in our mobile workshops. Because most of the work happens at the window, you rarely need to move out. However, we do ask you to clear the sill and curtains, so we can work safely.
When we finish, we test each sash up and down and check it holds at any height, because a balanced sash stays put. Then we tidy up and leave the window working smoothly.
What it costs
Sash re-cording and counterbalance is £120 per window. The overhaul and draught proof is £188 per window. A small splice repair is £80 and a bottom-rail repair is £120 if the frame needs it.
These are typical rates. However, large sashes, bays and difficult access can change them. As a result, we quote in writing after a free site visit. See the costs page for the full table.
Do not leave it
A window with a broken cord is a risk, because a heavy sash that will not hold can drop. It also leaves you with a window you cannot open for ventilation or close for security.
Waiting rarely saves money, since a sash that drops repeatedly can damage the beads and the frame. Fixing one cord early costs far less than repairing the damage later. Our guide to maintaining sash windows also shows how to spot worn cords before they snap, so you can plan the work.
Ask us to fix it
First, send a photo of the window and your postcode through the contact page. Tell us how many windows have problems. We cover all Greater London postcodes and often work just outside the M25, Monday to Friday, 08:00 to 18:00.