Mould on Windows: Causes and Solutions

mouldy window frame

Mould is a variety of fungus that flourishes in damp, dark environments. During winter, airborne droplets of water can come into contact with the cold, glass surface of your windows and settle. This provides mould spores with the habitat they need to flourish. This is terrible news for your windows, and it isn’t good for your health, either.

Can Mould on Windows Make You Sick?

If mould is allowed to accumulate, it will undoubtedly look pretty revolting – but does that necessarily mean it’s unhygienic, or even dangerous?

For asthmatics and those suffering from allergies, the answer is a definite yes. Mould reproduces by releasing microscopic spores into the air. If there’s enough mould on your window sill from condensation, then you’ll have a problem.

Even for those of us who aren’t affected by asthma, exposure to mould can lead to irritation of the eyes, skin, and lungs. The impact of prolonged exposure to mould is even more severe. For this reason, use a mask and gloves while you’re cleaning it up, and ensure that the area is well-ventilated. On that note, let’s look at how to clean mould off window frames and sills.

How to Get Mould off uPVC Windows

Cleaning uPVC requires a gentle approach. An abrasive cleaner can permanently (and quite easily) discolour the plastic.

Great results can be achieved with a combination of water and vinegar, at a ratio of around 4:1. Load the solution into a spray can and douse the affected area before wiping dry. The acids present in the vinegar will break apart the mould, allowing it to be easily scrubbed away.

How to Get Mould off Timber Windows

Now let’s look at how to remove mould from wooden window frames. Timber will react to moisture slightly differently to synthetic materials. Rather than sitting on the timber, those tiny water molecules will seep in between the fibres – which is why regularly treating your timber windows is so crucial.

You’ll want a different cleaning solution depending on whether your window is finished or unfinished. In the latter case, vinegar, baking soda, or a mixture of household detergent and water will do the trick. Unfinished wood might require a more caustic solution, since the mould may have penetrated into the grain. Rubbing alcohol is usually a good place to start.

How to Get Mould off Aluminium Windows

Since aluminium conducts heat better than timber or uPVC, it will get colder. This means more condensation, and consequently, more mould. However unlike uPVC, you can safely clean aluminium windows with bleach.

It’s easy to remove mould from aluminium window frames using a combination of bleach and water, at a ratio of around 1:10. Spray onto the affected area and wait for the bleach to break apart the mould before rinsing. When you’re done, dry the window quickly to prevent the mould from returning.

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