Bifold Door Glass Replacement: Keeping the Frame, Changing the Pane

A cracked or misted panel in a bifold door can almost always be replaced on its own, leaving the frame, tracks and other panels in place. The new glass must be safety glass, usually a toughened sealed unit, made to the exact size of that leaf. Once fitted, the leaf is checked so the doors still fold, run and lock smoothly.

Why bifold glass is different

Bifold leaves are tall, narrow and heavy, and the glass is a large part of that weight. Because they are doors at floor level, the glass must be safety glass, and most bifold units are toughened on both panes. The glazing also helps keep the leaf rigid, so the weight has to sit correctly on packers or the leaf can sag and start catching.

Common reasons for replacing a panel

The usual triggers are an impact crack, a pane that has shattered, or misting between the panes where the seal has failed. Misting is common on south facing bifolds that heat up strongly in the sun. In each case the fix is the same: a new sealed unit for that leaf.

• Impact cracks from furniture, balls or garden tools
• Toughened glass that has shattered
• Condensation trapped between the panes
• Scratches or etching that cannot be polished out

Measuring and ordering

The unit is measured from the leaf itself, noting overall size, thickness, spacer colour and any coatings so the new pane matches the others. Photos of the glass edge and any etched mark in the corner help. Because it is made to measure, there is a gap between measuring and fitting. If the pane is broken, the leaf can be made safe in the meantime.

Fitting the new unit

Depending on the system, the glass is changed with the leaf in place or with the leaf lifted off its track. The beads are removed, the old unit taken out, and the new one set on packers in the right positions to support the leaf. After re-beading, the doors are folded and unfolded several times and the locks tested.

If the leaf had already started to drop, this is a good moment to adjust the rollers and hinges as well.

Keeping bifolds running after a glass change

Keep the bottom track clear of grit and leaves, as debris is the most common cause of stiff running. A light clean of the rollers and a check that the leaves still meet evenly will catch problems early. Our guide to bifold doors that will not close covers running faults in more detail.

Before you book a glass change

Look at the corner of each panel for an etched mark and note what it says, as that confirms the glass type. Check whether all the leaves fold freely or whether the damaged one catches on the frame, because that points to a roller or hinge that may need attention at the same visit. Measure roughly how wide and tall the leaf is; it does not need to be exact, but it helps when planning access and whether two people are needed.

If the bifold is in a rental property or a flat, find out who is responsible for the doors and whether a managing agent needs to approve the work. Letting agents and landlords can arrange access directly. Finally, clear furniture from the inside of the doors so the leaf can be opened fully during fitting.

Call Mark on 07535 916982 or request a callback.