Causing structural damage and mould while increasing heating bills, window water leaks can be a serious problem for UK homeowners.
The climate, design flaws, age or incorrect installation can all cause windows to leak. Fast action is key to minimising damage, and the first step is to identify the source of the leak.
So, how can you find and stop a window water leak before it becomes a serious issue?
In this blog, we offer tips on how to prevent water leaks from windows and advice on how to deal with existing window leaks.
How to Find Window Leaks
If you think you have a leaking window, the first step is to confirm the source of the leak.
It may be that the source is obvious – if water flows or drips down a window frame during heavy rain. Other times, the signs are more subtle.
Signs of a window leak include:
- Dripping water
- Water stains – spots or discolouration, may be yellow or brown
- Water damage
- Condensation – internal or external
- Dampness, mildew or mould
- Draughts
- Cold spots
- Peeling paint
- Increased heating bills
Some of these signs can be caused by other issues, such as condensation on the inside of windows or energy inefficiency in other areas of the home.
So, how do you make sure you have found the leak?
Inspecting during rain is recommended. You can also use a hose to replicate leak conditions.
Check each part of the window – frame, flashing, sealant, and glass to ensure no cracks, holes, or gaps.
You can buy or hire neat-measuring equipment that will beep when it finds a leak.
If you cannot find the source of the leak, you need a professional. Some leak detection services focus solely on pipes and plumbing leaks. However, you can hire ‘damp investigation’ professionals who will use thermal imagery and other technology to diagnose the source of the problem.
What Causes Window Leaks?
The main causes of common window leak problems are:
- Poorly Installed Windows: Gaps, poor alignment, or inadequate sealant can all cause windows to leak.
- Damaged or Missing Flashing/Sealant: Flashing is a thin waterproof material installed around the window to direct water away, while sealant keeps it from trickling through the gap between the frame and glass. When damaged or missing, this protection is removed, and water can penetrate.
- Worn Seals: Most windows have silicone or rubber seals, which can deteriorate over time, creating an entryway for water. Weatherstripping can also wear out.
- Window Frame or Sash Damage: If the window frame is cracked, or rotted (timber), or the sash is broken, it will not keep water out.
- Clogged Gutters: When gutters get clogged, they no longer prevent water overflow from infiltrating windows.
- Clogged Drainage Holes: Many windows have holes built in for ventilation and drainage. Allowing these to get clogged can cause water to build up and leak, damaging window sills and the surrounding areas.
- Windows Not Closing Properly: If a window doesn’t close properly, there will be a gap creating draughts, and letting in water.
- Age of Windows: Older windows will degrade over time, leaving them vulnerable to water and draughts.
- Structural Issues: Cracks in walls or your roof can also cause windows to leak as water penetrates.
How Do I Fix Window Leaks?
The good news is that most window leaks have a relatively simple and inexpensive solution.
Here are a few DIY window leak fixes that should eliminate the problem:
- Reseal Windows - Use a sealant gun to apply high-quality silicone sealant around the window frame and spread with a palette knife to ensure gaps are properly filled.
- Recaulk the window - Remove the damaged caulk and apply new silicone caulk to seal cracks and gaps.
- Repair or replace any other damaged parts - such as the hinge, sash, or locks.
- Clean gutters and downspouts to redirect water away from windows.
These are short-term fixes, and may only work in tandem.
If you require a more long-term solution, you may need to replace the seals, flashing, glass or entire window.
For example, if the seal around the double glazing has broken and the Argon gas has escaped, it is impossible to put it back in. You will need to replace the double glazing.
How Can I Prevent My Windows from Leaking?
Prevention is better than cure. Once you have fixed the leak, you want to ensure it doesn’t come back. Even if your windows have never leaked, there are a few things you can do to ensure that continues.
- Inspect your windows regularly for signs of wear and tear
- Be proactive about weatherproofing older windows
- Clean your gutters regularly to ensure they don’t get clogged
- Ensure overhangs and sills are angled correctly
- Always use high-quality materials for seals and flashing
- Opt for professional installation to ensure the perfect fit
The maintenance will look different for UPVC vs aluminium windows or timber frames.
For example, the paint is more likely to peel or crack in timber windows. If aluminium hasn’t been treated, you may see water spots.
In all cases, regular cleaning and removing any debris is the first step to a fully functioning window. The most effective measure you can take (if your budget allows) is to replace your windows with A-rated, energy-efficient units.
How to Get in Touch
If you want to find out more about creating customised windows, doors, and conservatories, please don’t hesitate to get in touch. You can call us on 0161 976 4739, use our contact form or chat with us via the chat button at the bottom right of this website. If you live locally, you can also visit our Altrincham showroom, and check our contacts page for up-to-date opening hours.
We look forward to hearing from you!
FAQS
You may find you have more water leaking from windows during rain. This is because heavy rainfall or snow will enable water to accumulate much faster, exacerbating problems such as cracks or worn sealant. These conditions can also cause more condensation, which could be mistaken for a leak.
One small leak does not necessarily mean you need to replace your windows. Try the quick fixes outlined above before committing to new windows. However, if the leak recurs or others appear, and if there are other signs such as draughts or excessive condensation, window replacement might be necessary. If your windows are single-glazed, over a decade old or poorly installed, you should consider investing in new windows.
No, while it’s true that UPVC windows are not as durable as aluminium windows, properly installed and maintained UPVC windows are generally resistant to leaks. Issues such as damaged seals, improper installation, or age-related wear can cause UPVC windows to leak over time. Our UPVC windows have airtight seals and come with a 10-year insurance-backed guarantee for your peace of mind.
Leak detection costs in the UK typically range from £80 to £1,600 depending on the complexity of the issue and the detection methods used, such as thermal imaging or moisture meters. Window leak detection typically costs around £495 + VAT based on an engineer working with specialist equipment for around half a day.
