Top Tips To Stop Mould Around Windows

Top Tips To Stop Mould Around Windows

mould around windows

Many homes, particularly older homes, are prone to getting mould around windows. This can cause damage to window frames, especially timber ones, and cause health problems.

Whilst the mould certainly doesn’t look nice, it’s not the biggest problem. Living with mould in your house can lead to health problems.

Why Does Mould Grow Around Windows?

Mould is a fungus which can grow on almost any surface where moisture is present. The spores are present in the air and when they meet with moisture they grow and multiply.

The biggest cause of mould around windows is condensation. The warm air inside the home hits the glass of the window where it is rapidly cooled by the outside air producing condensation.

Other factors which increase condensation are:

  • Wet and humid weather
  • Insufficient heating
  • Leaking pipes
  • The steam caused by a bath or shower
  • Smoking
  • Open fires and wood burners

Why Is It A Health Problem?

mouldy windows

Mould exposure causes a variety of health problems, mostly respiratory.

Symptoms include:

  • Nasal and sinus congestion
  • Runny nose and sneezing
  • Eye irritation
  • Wheezing and problems breathing
  • Tight chest and coughing
  • Throat irritation
  • Rashes
  • Headaches

How Can Mould Be Removed?

mould windows

Due to the health problems it can cause, it is important that mould is regularly removed. There are a variety of ways you can do this depending on whereabouts of the mould.

The Best Way To Remove Mould From Around Windows Is Bleach

Wear rubber gloves and make sure that the window is open so that there is plenty of ventilation. Be careful not to get bleach on any paint, carpet or fabric as it will cause damage.

  • Mix one part bleach to three parts warm water in a bowl
  • Use a non-abrasive brush to clean off the mould
  • Regularly dip the brush in the bowl and thoroughly clean the whole area
  • Dry the cleaned surface with a cloth
  • Leave the window open until completely dry

There are lots of other sprays and cleaning detergents which can get rid of mould, but they don’t always remove the black staining. Some of these detergents can also damage the seal around double glazing, therefore, it is wise to approach with caution.

The best way to deal with mould around windows is to prevent it from growing in the first place. There are a few different ways you can tackle this.

How Can You Prevent It From Growing?

mould around windows

Mould is caused by condensation. Condensation is created by excess moisture, therefore, the best way to prevent it is to remove as much moisture as you can.

Opening Windows In The Bathroom And Turning On The Extractor Fan

Making sure than any steam created in your bathroom leaves via a window or extractor. This is important whilst the shower or bath is running and afterwards until the steam has gone. Wiping down wet surfaces once you have finished will also help.


Dehumidifiers are a great way of removing excess moisture in the air. They come in a variety of different sizes and price-points. Check out This Guide to find the best one for you. 

Keep Your Home Adequately Heated

Keeping your home heated evenly and not allowing the temperature to dramatically rise and fall will help prevent condensation. If warm air quickly becomes cold and then warm again it will produce moisture, causing condensation.

Double Glazed Windows

mould around window

The reason that mould is so common around windows is that the warm air from inside meets the cold air from outside. The best way to stop this is by creating an insulating layer between the cold outside and warm inside.

Good quality double or triple glazed windows do exactly that. Specifically designed to prevent heat passing from the inside to outside and vice versa. This means that the surface of the inner pane remains warm, creating significantly less condensation and therefore mould.

Prevention Is Better Than Cure

So, now you know why mould grows around windows, how to remove it and most importantly how to prevent it from growing.

If you want any further advice about maintaining your windows or installing more efficient ones get in touch with our friendly team.
We have a huge range of different windows to suit any home and can create made to measure windows that are perfect for your home.

Why Does Double Glazing Get Condensation On The Inside?

Why Does Double Glazing Look Misty?

Double glazing units are formed by two panes of glass with a gap between them. Depending on the rating of your double glazing, air or gas is trapped between the two panes and sealed in to create an insulating barrier. 

It’s only when this seal fails that condensation can build up on the inside of your windows causing them to appear misted up.

In addition to looking unsightly, the insulating benefits of the double glazed window are lost and the unit has become unstable.

The pressure of the air or gas reinforces the overall structure and stability of the unit. Without it, the glass panes will be flexible, fragile and dangerous.

why does my double glazing get condensation on the inside

What Caused The Seal To Break?

Whilst many people expect that doubled glazed windows will never need replacing. Unfortunately, this is often not the case.

Sealed double glazing units have a limited life span. For the highest-quality of installations, replacements may not be needed for up to 30 years. Some experts say that 20 years is a reasonable life expectancy.

Another likely cause is the use of chemical cleaners. These can cause the sealant to break down and allow moisture to seep in.

why does my double glazing get condensation on the inside

What Can Be Done To Prevent Double Glazing From Failing?

  1. When choosing which windows to install make sure that you choose the best quality units you can afford. At Abelglass we fit all our units with 28mm advanced performance, low emission glass and fill them with Argon gas.
  2. When cleaning the windows don’t use any solvents or harsh chemical cleaners. A simple solution of warm soapy water will remove any grime without damage to the sealant.
  3. Run your fingers around the beading that holds the glazed unit in the uPVC frame. If you notice that any part of this is not holding firmly, it may need re-applying to prevent moisture collecting in the frame.

Can A Failed Double Glazing Unit Be Repaired?

Whilst there are many companies offering a repair service, where the unit is drilled and the condensation is removed, it’s not something that we at Abelglass recommend.

Any repairs that can be made do not address the underlying issue as to why the unit failed in the first place. Additionally, the cost of high performance, Argon gas filled replacement is not too dissimilar to a repair. 

Simply put, there is no fix for a failed or ‘blown’ double glazing unit, unfortunately. It will need to be replaced.

If you’ve got double glazing with condensation on the inside, speak to Abelglass today to find out about the best replacement for you.

why does my double glazing get condensation on the inside

Our family-run company has supplied the highest quality uPVC windows for over 30 years.

Call us on 01253 893355 or 0800 136128 to speak with one of our professional team of glaziers.

It's beginning to look a lot like Christmas 🎄


22nd December
3rd January 2024


Order NOW for pre-Christmas delivery 🚚

✅ Composite and uPVC Doors

✅ uPVC Frames


Toughened Glass
13th December
15th December
21st December
Last date for deliveries
Last date for collection