Cracked Double Glazed Unit

A cracked double glazed unit is a common issue in uPVC windows, where the sealed glass panel develops a visible fracture. This symptom often signals a failure in the glazing, potentially leading to draughts, noise ingress, or water leakage if left unchecked. At Window Repairs Sutton, we specialise in uPVC window repair for such problems, drawing on over 10 years of experience with local homes in Sutton.

What This Usually Means

Spotting a cracked double glazed unit typically indicates damage to the sealed glass pane between two layers of glazing. The crack appears as a line across the glass, sometimes with a slight bulge or misting if the seal has also failed. This isn’t usually a frame issue but a glazing problem that compromises insulation and security.

In most cases, the outer pane cracks first due to impact or stress, while the inner remains intact. It means reduced energy efficiency, as argon gas between panes escapes, making your home colder. Early attention prevents escalation to full window repair needs.

Common Causes

Several factors contribute to a cracked double glazing unit in uPVC windows.

• Impact damage: A stray football, bird strike, or accidental knock from garden tools often causes the initial fracture.
• Thermal stress: Rapid temperature changes, like hot sun on one side and cold shade on the other, create pressure leading to cracks.
• Manufacturing defects: Rarely, weak points in the glass from production cause spontaneous cracking over time.
• Frame movement: Poor window adjustment or settlement in the building can flex the frame, stressing the glazing.
• Age and wear: Units over 10-15 years old become brittle, especially if hinges or locks fail and put uneven pressure on the glass.

These causes are typical in Sutton’s varied weather, where freeze-thaw cycles exacerbate stress on older installations.

Safe Checks Before Booking

Before calling for window repair, perform these straightforward, safe inspections to confirm the issue and avoid unnecessary costs.

• Inspect the crack: Shine a torch at an angle to check if it’s on the inner or outer pane. Outer cracks are common from impacts; inner ones suggest pressure issues.
• Test for movement: Gently push the window frame. Excessive wobble points to hinge or window adjustment problems contributing to the crack.
• Check seals: Look for misting or moisture inside the unit, indicating a blown seal alongside the crack.
• Feel for draughts: Hold a lit incense stick near the edges; smoke pulling in confirms a breach.
• Safety first: Avoid touching sharp edges or forcing the window open. Tape over the crack temporarily with clear packing tape to contain shards.

These checks take minutes and help our DBS-checked technicians diagnose quickly upon arrival. Note any related symptoms like sticking or whistling for better service.

Likely Fixes

Addressing a cracked double glazed unit usually involves targeted replacement sealed unit or full repair, depending on the damage extent. Here’s a decision guide to route you correctly:

• Isolated crack on one pane, frame intact? Opt for a replacement sealed unit – we supply and fit matching sizes from our parts range, restoring insulation without full sash removal.
• Crack with misting or gas loss? Book double glazed unit replacement via our specialist repairs service, where we swap the entire unit on-site.
• Frame misalignment causing stress? Combine with uPVC window repair including toe and heel adjustment to prevent recurrence.
• Multiple cracks or shatter risk? Prioritise replace cracked window glass unit through professional fitting to ensure safety and weathertightness.
• Accompanying lock or hinge issues? Integrate window lock repairs or friction stay replacement during the visit for comprehensive fixing.

Our public liability insured team handles these efficiently, focusing on uPVC systems we service. Avoid DIY glass handling due to injury risks.

FAQs

What does a cracked double glazed unit look like?

It appears as a straight or spiderweb line across the glass pane, often on the exterior side. You might notice internal misting if the seal breaks too. It’s distinct from frame cracks, which follow the uPVC profiles.

Can I repair a cracked double glazed unit myself?

No, self-repair risks further damage or injury. Glazing requires precise tools and matching units; our uPVC window repair experts ensure a secure, warranty-backed fix.

How much does it cost to replace a cracked double glazed unit?

Costs vary by window size and type, but expect competitive quotes for replacement sealed unit work. Contact us for a no-obligation assessment tailored to your Sutton property.

Will a cracked unit affect my home insurance?

Yes, if caused by an insurable event like storm damage. Document the crack and causes before repair; we provide detailed reports for claims.

How long does double glazed unit replacement take?

Most jobs complete in under two hours per window, weather permitting. Our local Sutton base means prompt scheduling without fixed response promises.

Does Window Repairs Sutton handle cracked units in older windows?

We focus on uPVC systems matching our services offered, excluding sash or wooden frames. Check compatibility during your contact.

Can window adjustment prevent future cracks?

Yes, proper alignment reduces stress. If hinges are worn, our window hinge replacement service addresses root causes alongside glazing fixes.

Is a small crack in double glazing urgent?

Monitor for spread or draughts, but act soon to maintain efficiency. Tape it safely and book via phone for peace of mind.

Call To Action

Don’t let a cracked double glazed unit compromise your home’s comfort or security. With liability insurance and 10+ years serving Sutton, Window Repairs Sutton delivers reliable window repair solutions.

Call 020 8138 0796 today or contact us for fast, honest advice. Explore other issues on our symptoms page in the meantime.