Window Frame Repair in Dunedin

Frames fail differently depending on what they are made of and where in the city they sit. Timber goes at the sill once the paint film breaks. Aluminium corrodes at the corners and around the fixings, fastest within a few hundred metres of the water on the south coast and up the harbour. uPVC goes brittle under UV. Knowing which one is in front of you decides whether the fix takes an hour or a week.

Finding the leak before sealing anything

A wet internal sill has several possible causes and only one of them is the seal. Blocked drainage backs water up over the frame. A failed head flashing lets water in above the window and it appears at the bottom. Perished glazing wedge lets water past the glass. A racked sash leaves a gap at one corner.

We water test in stages, bottom up, until the leak shows itself. Running silicone around the outside of a window without knowing why it leaks is the most common bad repair we get called out to undo, because it traps the water inside the frame instead of letting it drain.

Timber frame repair

Rot follows the water. The sill first, then the bottom of the jambs, then the bottom rail of the sash. Everything above that is usually sound old growth timber worth keeping.

We cut back to solid wood, scarf in new timber, glue and pin it, shape it to the original profile and prime it before it leaves. Where a sill has gone completely, a full sill replacement into the existing frame still costs far less than new joinery.

Aluminium corrosion and racked sashes

Aluminium frames rarely fail structurally. What fails is the corner joints, the fixings and the coating. Open corners let water track into the wall rather than the room, which is worse and harder to spot. Chalky white bloom means the powder coat has been breached.

Sashes that catch on the frame or leave a triangular gap have usually dropped rather than warped, and that comes back to worn hinges, stays or rollers. New hardware and a resquare fixes the gap. Replacing the window because it will not close properly is the expensive way to solve a hardware problem.

When replacement is the honest answer

Pitting right through the aluminium. Timber that is soft through the full section rather than just at the face. Corners open so far the frame is no longer square. uPVC gone chalky and brittle enough to crack when you screw into it.

In those cases we quote the replacement and explain why. What we will not do is quote a replacement on a frame with fifteen good years left in it because it is the bigger invoice.

Diagnosing a frame before quoting it

Square, straight and tight

Three checks tell you most of what you need. Is the frame square, measured corner to corner. Is the sill straight along its length. Are the corner joints tight when you press them.

A frame that passes all three is worth repairing almost regardless of how it looks, because coating and hardware are surface problems.

When to stop

Aluminium pitting through the extrusion, timber soft through the full section rather than at the face, corners opened far enough that the frame has racked, or uPVC gone chalky enough to crack when a screw goes in.

Those are the four we will tell you to replace, and you get both prices with the reasoning rather than just the bigger number.

Window Frame Repair at a glance

Materials

Aluminium, timber, uPVC and composite frames

Leak testing

Water tested bottom up, cause identified before any sealing

Timber repairs

Scarf repair, bottom rail replacement, full sill replacement

Aluminium repairs

Corner joints resealed, coating restored, hardware replaced

Sash squaring

Hinges, stays and rollers replaced, sash rehung and adjusted

Finish

Timber primed ready for paint, aluminium touched up to colour

Assessment

Repair and replacement priced side by side on the same quote