1. Support the sash and label the trim

Raise and support the sash before removing staff beads or trim. Work gently with a small pry tool, keep screws in a tray and label parts so they return to the same side and orientation.

• Take photos before removing each piece.
• Cut through paint lines with care rather than forcing trim away.
• Support the sash with blocks so it cannot drop unexpectedly.
• Keep old painted debris controlled, especially in older homes.

2. Open the pocket and inspect the weight

Traditional sash boxes often have a pocket cover that gives access to the hidden weight. Remove it carefully, then check the condition of the weight, pulley and old cord path before cutting anything free.

• Work one side at a time so the window stays controlled.
• Check that the pulley turns freely and is not badly worn.
• Match the new cord to the sash weight and pulley size.
• Do not drop the weight into the box cavity.

3. Thread the new cord and secure it

Thread the new cord over the pulley, attach it securely to the weight and reconnect it to the sash. Leave enough travel for the sash to open fully without the knot fouling the pulley or pocket.

• Use the original attachment method as a guide if it was sound.
• Keep knots compact and secure.
• Check cord length before trimming the excess.
• Repeat the same process on the other side if both cords are tired.

4. Refit trim and test movement

Refit the pocket cover and beads in their original positions, then test the sash slowly. It should rise and lower smoothly without dropping, binding or twisting. If it sticks, check alignment before forcing it.