Single Glazing Repairs in London: Panes, Putty and Draughts

Plenty of London homes still have single glazed windows: timber sashes in Victorian terraces, steel or timber casements in 1930s semis, and small panes in porches, outbuildings and internal doors. When one pane cracks, the putty falls away or the window starts to rattle, you rarely need a new window. Mark replaces the single pane, beds it back in properly and deals with the draughts, keeping the original frame in use.

• Cracked or broken single panes cut and fitted to the existing rebate
• Old, cracked putty raked out and the pane re-bedded
• Beaded panes refitted with new glazing beads where the old ones have split
• Safety glass fitted where the opening needs it, such as low panes and doors
• Draught-proofing for original single glazed sashes
• Honest advice on whether a slimline double glazed unit could fit your frame

Single glazing work is a different craft from swapping a sealed unit. There is no factory-made unit to order; the pane is measured to the rebate, cut to size and set in either linseed putty or behind timber beads, depending on how the window was built. Getting that right is what stops water sitting on the bottom rail and rotting the frame from the inside.

Putty is the part most people forget about until it fails. Over the years it dries, shrinks and cracks, and rain gets in behind it. You might notice gaps along the edge of the glass, flakes of old putty on the sill, or a pane that moves when you press it. Where that is happening we rake the old putty out, check the rebate for soft timber, prime it and re-bed the glass so it sits tight again.

A single cracked pane is not always a like-for-like swap. Panes close to the floor, in or beside doors, and in bathrooms often need toughened or laminated glass today even if the original was plain float. We check the position of each opening before quoting so the new pane is the right type for where it sits, and tell you up front if that changes the spec.

Draughts are the other big complaint with older single glazed windows. On sashes the gaps are usually around the meeting rails, the staff beads and the parting beads, and much of that can be reduced without changing the glass at all. Our sash window repairs page covers the mechanical side, such as cords and weights; this page is about the glass and the seal around it.

Sometimes people ask whether they should simply switch to double glazing. On some frames a slimline double glazed unit can be fitted where the sash design allows it; on others the rebate is too shallow, or conservation rules mean original single glazing should stay. We will say which applies to your window rather than push you towards the bigger job.

If a single pane has broken and the opening is not secure, our emergency boarding up service can make it safe first, with the permanent pane fitted on a follow-up visit once it has been cut.

For quoting, a clear photo of the whole window plus a close-up of the damaged pane helps a lot. Include a tape measure across the glass if you can. That lets Mark confirm the likely glass type and whether the frame is putty or beaded before he comes out.

How the repair works

1. 1. Check the frame and rebate We look at how the pane is held, test the timber around it and confirm the glass type the opening needs.
2. 2. Remove, prepare and cut Broken glass and old putty or beads are removed safely, the rebate is cleaned and primed, and the new pane is cut to fit.
3. 3. Bed, seal and tidy The pane is bedded and puttied or beaded, the edges are finished neatly and the window is left ready for painting once the putty has skinned.

Call Mark on 07535 916982 or request a callback.