Many homeowners think of blown double glazing and window lock issues as separate problems. In fact, one can lead to the other. A failing or misaligned lock may gradually distort frame geometry, worsen seal stress, and contribute to a blown (misted) double glazed unit. In this article, we explore that connection, the repair costs you should expect, and why acting early in Brighton or Sussex can save you serious money.
How faulty window locks can accelerate glazing failure
1. Frame stress & misalignment
- A lock that’s tight, misaligned or forced can pull one sash unevenly, causing stress on the perimeter seal of the unit.
- Over time, even small distortions can fatigue the seal, allowing moisture ingress.
2. Incomplete closure or drafts
- If the lock doesn’t fully engage, the sash may never press snugly against the seal, leaving micro-gaps. Those micro-gaps encourage condensation ingress and seal failure.
- That partial opening also allows warm humid interior air to press deeper into the frame structure, further testing the seals.
3. Vibration & fatigue
- Everyday use, wind, or door slams can cause micro‐vibrations. A solid, properly aligned lock constrains movement. A weak or loose lock lets slight motion occur, gradually loosening the seal.
So, in a sense, window lock repair and double glazing longevity are intimately linked. Fix the lock before it contributes to a blown unit, and you may postpone or prevent a costly glazing replacement.
What is “blown double glazing”? Signs, causes & repair options
Signs your double glazing is blown (i.e. seal failure)
- Persistent condensation or fog/misting between the panes
- Moisture – water droplets, streaks, or staining inside the panes
- Cloudy or dull appearance you can’t clean off
- Draughts or cold spots near the window
- Noticeable rise in heating or energy bills
- The view becomes slightly blurred or distorted
These are well-known indications of a failed sealed unit.
Causes of blown glazing
- Seal degradation over time (age, UV, temperature cycling)
- Structural stress or movement (e.g. frame distortion, sagging)
- Poor installation or compromised seals from the outset
- Mechanical damage, e.g. small chips or knocks
- Moisture ingress via microgaps in frame or glazing beads
Repair vs replacement: what’s feasible
If your frame is warped or compromised (for instance due to lock misalignment or frame movement), replacing the sealed unit won’t fix everything; the underlying frame may need adjustment or reinforcement.
In most cases, a blown unit is repaired by replacing the double glazed unit (i.e. the sealed glass “billet”) rather than the whole frame.
Some specialist methods attempt to dry and reseal a unit in situ, but these tend to be less reliable long-term.
Cost guide: What you’ll pay in Sussex / Brighton region
Blown double glazing / misted window repair cost
- According to Checkatrade, repairing a blown window unit in the UK ranges from £55 for small windows up to £600 for large or complex ones.
- Locally in Brighton, misted double glazing repair (i.e. replacing the sealed unit) is offered by specialist firms.
- Replacing the panes (not frame) helps reduce cost.
Condensation / double glazing condensation repair cost
- Typically the condensation repair is synonymous with blown glazing repair (i.e. replacing the sealed unit). So the above ranges apply.
- Additional costs may arise if the frame or seals around the bead/gasket need renewing.
Window lock repair cost
- Lock repair is much cheaper in comparison. In Brighton, firms specialising in uPVC window & door lock repair advertise local services.
- The cost largely depends on the complexity: simple lock realignment or screw re-tightening may be modest (tens of pounds), but replacing multi-point locking gear or mechanisms can run higher.
UPVC door repair cost
- UPVC door repairs often involve similar locks, hinges, gaskets or seals and thus mirror some of the window repair cost logic.
- Because door units are larger, costs are typically higher, especially if the central locking gear or mullion mechanisms are damaged.
- Why acting on lock repair early is a smart strategy
- Save on glazing costs — If a blow happens, replacing the glass is far more expensive than getting a lock serviced.
- Extend the life of your window unit — A stable sash means less seal fatigue.
- Improve security & comfort — A functioning lock enhances security and ensures good closure, reducing draughts and heat loss.
- Minimise disruption — Lock repairs tend to be quick, whereas blown glazing replacements may require scheduling, lead time for glass, and more disruption.
What to look for locally in Brighton / Sussex
- Seek a repair specialist who handles both window locks & blown glazing (so they can spot the cross-effects).
- Ask for separate line items in the quote (lock repair vs sealed unit replacement).
- Ensure they use quality gaskets, spacers and gas fills in sealed units.
- Check for guarantees on sealed units (5–10 years is not unusual with good installation).
- Ask whether they will check and, if needed, adjust frame geometry during installation.
Why Customers Across Brighton Choose Sussex Glazing Solutions
🏡 Local and Trusted – We’re based in Sussex and understand the specific needs of homes in the Brighton and Hove area.
🔍 Comprehensive Repairs – We don’t just do windows—we handle door lock repairs, blown glazing, hinge issues, and more.
⚡ Fast Response – Quick turnaround times so your home stays safe and secure.
👍 No Pushy Sales – We always look for the most cost-effective solution for you.
Book Your Repair Today
From blown double glazing to UPVC door lock repairs, we’ve got Brighton covered. Don’t let minor issues turn into costly problems—get in touch today for a free quote.
📞 Call us now at 01273 025 185
📧 Email us at info@sussexglazingsolutions.co.uk
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