Why does my sash window keep dropping?
A sash that slides down on its own, slams shut, or simply won't stay where you put it is one of the most common calls Matt gets from homeowners across Sydney and the Inner West. It's frustrating, it can be dangerous with small children or pets around, and it often gets worse over time. The good news is that a dropping sash is almost always repairable, and it rarely means the window needs replacing.
How a sash window is meant to hold itself open
A traditional sash window is a clever piece of engineering. Each sliding sash is balanced so that it feels almost weightless and stays exactly where you leave it. In older homes this is done with cords and weights: a cord runs from the side of the sash, over a pulley at the top of the frame, and down to a cast iron or lead weight hidden inside the box frame. In many later era homes the same job is done by spiral balances, which are spring loaded tubes fitted into the side of the frame.
When everything is in balance, the sash holds itself open. When something in that system fails, gravity wins and the sash drops.
The most common causes
A snapped or frayed sash cord. Cords wear over decades of use, and once one breaks the sash loses half its support.
A weight that has come loose from its cord and dropped to the bottom of the box frame.
Worn or broken spiral balances that have lost their tension.
Sashes that were reglazed or repaired in the past without being rebalanced, so the weights no longer match the sash.
Paint, swelling or old repairs that have changed how the sash sits and moves in the frame.
Signs to look out for
Often a window gives warning before it fails completely. You might notice the sash creeping down slowly after you open it, one side sitting lower than the other, a cord that looks thin or furry where it passes over the pulley, or a clunk inside the frame when you open the window. If the top sash has dropped a few centimetres and won't stay closed, that's usually the same problem in reverse.
Is it safe to keep using it?
A sash that drops suddenly can trap fingers, and a sash with only one working cord puts extra strain on the one that's left. Until it's repaired, it's best to keep the window closed or prop it securely, and keep children away from it. Avoid forcing a window that feels jammed, as that can crack glass or damage the frame.
How Matt fixes a dropping sash
For cord and weight windows, Matt opens the pocket in the frame, retrieves the weights and fits new cords to every sash, not just the one that has snapped. Replacing them all at once means the window runs evenly and you won't be calling about the other side in a few months. He then rebalances the weights so each sash glides with one hand and stays put. You can read more on the sash cord replacement page.
For windows with spiral balances, Matt replaces the worn balances with correctly sized new ones and repairs any damage to the sash where they attach. More detail is on the spiral balance repairs page.
Either way, the window is also checked for paint build up, sticking and draughts while it's apart, because that's the most efficient time to sort them out.
Why not just replace the window?
A dropping sash is a mechanical problem, not a sign that the window has reached the end of its life. The timber in older Sydney homes is often far better quality than anything available today, and with new cords or balances the original window can keep working for decades. Repair keeps the character of your home and usually costs far less than replacement.
Not sure which system your windows have?
If you're not sure whether your windows use cords and weights or spiral balances, that's fine. A clear photo of the side of the sash and frame is usually enough for Matt to tell. Our guide to cords, weights and spiral balances explains how to check for yourself, and the problem guide covers other common faults.
Get your window working again
Call Matt on 0409 448 107 or send him a photo through the quote form. Every job is quoted, overseen and signed off by Matt.
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