Blog>Expert Advice>What to do if your Velux window is cracked
Last updated: 18 September 2024
What to do if your Velux window is cracked
A cracked Velux window can be hazardous. In this guide, we'll look at what to do if you discover your Velux window is cracked.

In this article you'll find:
The most important thing to do with a cracked Velux window is to fix it. And quickly. How you fix it will depend on why the issue happened in the first place.
Read on for the possible causes and solutions to prevent the crack from widening.
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Do Velux windows crack?
Any window can crack.
Although highly durable, Velux windows can also crack and leak.

Potential causes of Velux window cracking
Velux windows are built to last.
So, it can be frustrating to find an unexplained crack in your skylight or roof window.
If you have a crack in your Velux window, potential causes include:
1. Thermal stress
Velux windows are typically installed on roofs, ceilings, and attics. This means they must withstand various weather conditions and temperatures.
These temperature changes from cold to hot and vice versa can result in thermal stress. The glass cannot cope with the stress, and cracks form.
2. Manufacture issues
Although unlikely, manufacturing flaws can crack a Velux window.
Like a windshield, a small crack can lead to a big one over time.
3. Accidental damage
Velux windows are hardy and built to withstand impact damage. But, accidental damage or storms can lead to cracks.
4. Installation issues
Stress points can form on the window pane if your Velux window is poorly installed. These stress points can lead to cracks.
A faulty window seal or slightly off frame can also result in cracks in the pane.
5. Velux window recalls
The Velux website has a safety product warning.
Check the Velux website if you bought a window produced and sold between 1997 and 2003 with pane code 00UE.
These are at risk of spontaneous breakage, which causes the glass to fall.
6. Seal problems
When Velux windows aren't sealed effectively, it can affect their durability.
If the seal fails on one side, it might create a cooking effect. The exterior pane can become extremely cold, and the interior pane can become very hot.
Again, the glass cannot cope and can crack.

Early signs of a cracked Velux window
When Velux windows crack, they can be so subtle that they may be hard to spot.
Identify the early signs of a Velux window crack to avoid safety hazards and prevent further damage.
Watch out for these early signs of a minor or developing crack:
Hairline cracks - small, thin cracks can expand over time
Condensation - cracks inside the pane or a faulty seal can cause condensation
Drafts - if a cosy room now feels drafty, a small crack could be letting cold air in
Cloudy or foggy glass - the structural integrity of the glass may be weakening
Water - during heavy rain, you might notice staining, water droplets, or damp patches around the window frame
Creaking or popping noises - this could be the start of a minor fracture or the glass responding to temperature changes
Noticing a crack in your window early might result in a replacement under your warranty. Dealing with the problem pronto can also save you money and safe from safety hazards.

Velux window replacement cost
The costs of dealing with a cracked Velux window depends on several factors. These include whether you need a repair, glass-only replacement or a whole new unit.
Generally, a Velux window replacement costs between £550 - £1,500.
We recommend getting multiple quotes to compare.
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FAQs
What is the life expectancy of a Velux window?
Velux offer a 10-year guarantee for roof windows and flat windows.
But when properly maintained, Velux claims that their windows have a life span of 20 to 30 years.
Some things you can do to make sure your Velux windows last are:
Ensure proper installation
Undertake regular maintenance
Avoid heavy use (too much opening and closing)
Can Velux windows be repaired?
Yes, Velux windows can be repaired. But it depends on the size and severity of the crack.
You may be able to repair a minor crack yourself with a glass repair kit.
But this is not a permanent solution. If you see your crack enlarging or if it is already large, consider replacing the glass or window.
Can you replace just the glass in a Velux window?
Looking for a more cost-effective solution to restore your Velux window's appearance and function?
You might only need to replace the glass, not the whole unit/
Just make sure it's only the glass that is:
Damaged
Cracked
Lacking insulation
How long does it take to replace a Velux window?
It might take less time than you think to replace a Velux window.
A like-for-like replacement can often be done in just a few hours.
However, upgrading to a larger window, a different type, or additional windows might take one to two days.
A Velux window installer can tell you how long your replacement might take.
How do I fix a Velux window cracked on inside?
It's always best to employ a professional to replace a cracked Velux window.
But, whether you hire a professional or do it yourself, you will need to:
Assess the damage to check if you can replace the glass or the whole unit
Find the model number on the metal plate on top of the window frame when open
Get quotes for a replacement window from Velux or a certified installer
Order double or triple-glazed glass - use the model number to order replacement glass from Velux or an accredited supplier (your window installer may be able to do this for you)
Find a certified Velux window installer to install your new window pane and help with any other issues
Remove the damaged Velux window
Install the new Velux window
Test the Velux window
Replacing window glass, especially on a roof or ceiling, can be dangerous.
It's best to leave steps six to eight to a tradesperson. Improper installation can void a warranty, cause energy efficiency issues, or create safety hazards.

Can I replace my own Velux window?
Notice the early signs of a cracked window? Ignoring a cracked Velux window may lead to potential safety hazards.
Without the right experience, it's safer to trust your Velux window repair to the professionals.
Organise a prompt repair to avoid water damage, mould, structural damage or risk of injury from falling glass.
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