How do I remove uPVC glazing beads without breaking them?

uPVC beads clip into a groove with a small barb. They are easy to remove and easy to snap, and the difference is entirely about where you start and how you lever.

Safety

What you'll need

• A stiff putty knife or a purpose-made bead lifter
• A rubber mallet
• Masking tape
• A pencil
• Gloves

Step by step

1. Confirm which side is beaded.Modern windows are internally beaded, which is a security feature — the glass cannot be removed from outside. Older and some commercial units are externally beaded.
2. Mark the beads before removing them.Pencil a number on the back of each and note which edge it came from. They are cut to length and mitred, and swapping two makes a visible gap.
3. Start with a short bead.The top or bottom, whichever is shorter. Short beads are stiffer and easier to release; releasing one gives the others somewhere to move.
4. Insert the tool at the middle of the bead.Push the blade into the joint between the bead and the frame at the centre of the length, angled slightly, until it is behind the bead.
5. Twist, do not lever.Rotate the blade so the bead's barb pops out of its groove. Levering the blade like a crowbar marks the frame and snaps the bead.
6. Work outwards to the ends.With the middle free, run the tool along in both directions releasing the barb progressively. The mitres come out last.
7. Support the glass before the last bead.Tape the glass to the frame or have someone hold it from the other side. As the last bead comes out, the unit is held by nothing but its packers.
8. Note the packer positions.Photograph or mark where the plastic packers under and beside the glass sit. Refitting the glass without its packers is the fastest way to make a window impossible to close.
9. Refit long beads first.The reverse of removal. Tap them home with the heel of your hand or a rubber mallet, starting from the middle and working out, so the mitres close properly.
10. Check the mitres.A bead that will not seat leaves a visible line at the corners. It usually means a packer has shifted or the bead is in the wrong position.

Tips

• A dedicated bead lifter costs a few pounds and is shaped so it cannot dig into the frame. Worth having if you expect to do this more than once.
• Cold beads are brittle. On a winter day, warm the room first or bring spares — old beads snap far more readily in the cold.
• If a bead has to be replaced, take a sample. Bead profiles are system-specific and there are many of them.

Common mistakes

• Starting at a mitre — The mitred end is the weakest point of the bead and it is trapped by the adjoining bead. Levering there splits the mitre and the corner never closes properly afterwards.
• Refitting the glass without its packers — Packers set the glass square in the sash and carry its weight at the correct points. Without them the sash distorts, the window will not close, and the sealed unit is loaded at its corners where it can crack.

If it doesn't work

Questions people ask