How to Fix a Window That Has Dropped and Won't Shut Flush

A window that has dropped and won't shut flush is a common problem in New Zealand homes, particularly in older villas, bungalows, and houses with timber joinery. In most cases the fix is straightforward — loose or worn hinges, a failing window stay, or minor frame movement are the usual culprits. Here's how to work through the problem step by step.

Diagnose the Problem First

Before reaching for a screwdriver, take a close look at what's actually happening. Open the window fully and check:

• Where is the gap? Is the window sitting lower on the hinge side, the latch side, or dropping evenly?
• Do the hinges look loose or corroded? Grab the sash (the opening panel) and gently try to lift it — if there's noticeable play, the hinges are likely the issue.
• Is the frame itself out of square? Use a tape measure to compare the diagonal measurements of the frame opening. If they differ by more than a few millimetres, the frame may have racked or the surrounding structure has moved.
• Is the window stay (the arm that holds the window open) bent or detached? A broken stay can allow the sash to sag under its own weight over time.

Tighten or Replace the Hinges

Loose hinges are the most common cause of a dropped casement or awning window. Here's what to do:

1. Open the window and support the sash so it doesn't swing freely.
2. Check every hinge screw. If screws are loose, try tightening them with the correct screwdriver (usually a Pozidriv or Phillips head).
3. If the screw holes are stripped (the screws just spin), remove the screws, pack the holes with wooden toothpicks or a small timber plug and wood glue, let it cure fully (usually overnight), then re-drive the screws. This gives the threads something solid to bite into.
4. If the hinges themselves are bent, corroded, or cracked, replace them with like-for-like hinges of the same size and weight rating. Take the old hinge to Bunnings or Mitre 10 to match it up. For aluminium joinery, check with a glazier or joinery supplier as proprietary hinges may be required.
5. Once new hinges are fitted, check the window closes flush. If it's close but not perfect, most hinges allow a small amount of adjustment — loosen the screws slightly, shift the hinge leaf, and re-tighten.

Check and Replace the Window Stay

The window stay (also called a casement stay or friction stay) holds the window open at a set position and also supports the sash weight. A worn or bent stay can let the sash drop gradually.

• Inspect the stay arm and its pivot point for bending, cracking, or loose rivets.
• Check that the stay pegs (the pins the stay locks onto) are firmly fixed to the sill.
• If the stay is a friction stay (common on aluminium windows), the friction mechanism may simply need tightening — there is usually an adjustment screw on the pivot. Consult the manufacturer's instructions if available.
• Replacement stays are available at hardware stores. Match the length and fixing pattern of the original.

Adjust for a Racked or Swollen Frame

Timber frames can swell with moisture or rack slightly as a house settles. If the frame is only mildly out of square:

• Planing the sash edge can create clearance so the window closes properly. Remove the sash from its hinges, plane the binding edge a little at a time, and rehang to test the fit. Seal any bare timber with paint or primer immediately — bare timber absorbs moisture and can swell again. Resene and Dulux both offer suitable timber primers.
• If the frame has racked significantly, this may point to structural movement in the wall framing — see the section below on when to call a professional.

Check the Latch and Striker Plate

Sometimes the window appears dropped but the real issue is a misaligned latch. If the latch bolt no longer lines up with the striker plate:

• Loosen the striker plate screws and shift the plate slightly up or down to align with the latch bolt.
• If the misalignment is large, you may need to chisel out the recess and reposition the plate.

Weathertightness and the NZ Building Code

A window that won't close flush is more than an inconvenience — it can allow wind-driven rain to enter the wall cavity, leading to moisture damage and potential issues under NZ Building Code clause E2 (External Moisture). If you notice staining, soft timber, or mould around the frame, address the underlying cause promptly. BRANZ has useful guidance on weathertightness for homeowners. For rental properties, landlords should also be aware of obligations under the Healthy Homes standards.

When to Call a Professional

Call a qualified glazier or Licensed Building Practitioner (LBP) if:

• The frame is significantly racked or out of square, suggesting structural movement in the wall.
• The window sash or frame is rotted, cracked, or damaged beyond simple repair.
• The glazing unit (double-glazed panel) has been damaged or has broken its seal — replacing glazing units is specialist work.
• You have aluminium or uPVC joinery with proprietary hardware that requires manufacturer-specific parts.
• The window is large, heavy, or located at height where working safely is difficult.

For structural concerns, an LBP should assess whether a building consent is required before any remedial work — always check with your local council. You can find qualified glaziers and builders in your area on tradedirectory.co.nz.

Safety note: When working on windows at height, always use a stable platform or ladder and have a second person to assist. Never lean out of an upper-storey window to work on the outside of a sash.

Sources & Further Reading

• BRANZ – Weathertightness and moisture
• MBIE Building Performance – NZ Building Code
• Licensed Building Practitioners – Find an LBP
• Tenancy Services – Healthy Homes standards
• Bunnings – Window hardware and hinges
• Mitre 10 – Window stays and joinery hardware