Green Mould On Skirting Boards? Here’s Why

Especially in the UK, where the rain seems to never cease, green mould is a common occurrence. Now, it’s common in just about every damp environment and will spread if left unattended. If you’re noticing green mould on your skirting boards, it’s important to act quickly. There are a few things you can do at home before calling in the professionals, but you need to act quickly.

To treat green mould on skirting boards, use a diluted bleach solution or a mixture of baking soda and vinegar.

There’s a bit more to talk about than just treatment, so let’s get right into it.

Green Mould on Skirting Boards: Causes and Prevention

Green mould is actually a rather broad subtype of fungus. It can come in a lot of forms, but the three most common ones are:

  • Cladosporium
  • Aspergillus
  • Penicillium
    • As a note, however, all of these moulds can also take on blue, white, or black colours as well.

First things first, all mould is toxic to people and pets and should be removed as soon as possible. Among other health issues, continued exposure to mould can cause allergy-like symptoms, as well as pneumonia and lung inflammation. This makes it highly important to be dealt with, especially for those who are immunocompromised or suffer from asthma. If you suddenly find yourself experiencing any of the following symptoms, it’s time to check for mould:

  • Runny nose
  • Watery eyes
  • Cough
  • Itchy skin
  • Decreased lung capacity or shortness of breath

The best ways to prevent mould in the first place are heat, ventilation, and minimising moisture in your home. Let’s talk a bit about how to do that, yeah?

Read Next: Towel radiator not working? Try this.


During cold weather, you’re likely tempted to keep the heat cranked. That’s entirely okay – assuming you do it across your home equally. If you run the heat in a single room, the other rooms in your home will have an increase in condensation, leading to mould.

If you can’t run the heat in every room, at the very least, try to keep all doors open and windows closed. This will allow the heat to spread evenly and prevent outside moisture from making its way in. In addition, using heaters such as portable bottled gas heaters can release extra moisture, so try to avoid using them.


Now we’ve talked about this a lot on Dreamy Home. Not only does it help keep your home’s air from getting stagnant, but it helps prevent condensation and moisture. If you have them, make use of trickle ventilators. If not, crack a window every night to help circulate air.

Ensuring that clothing has room for air to circulate will prevent it from moulding. Keeping a small gap between furniture and wardrobes will do the same, and keeping them against internal walls will further reduce the chances of mould. Finally, be sure to use the extractor fans in your bathroom and kitchen. They will move moist air away from your home and ensure there’s proper ventilation across the whole building.

Finally, just like above, keep your doors open (when you can). This will allow air to circulate and further reduce the chances of getting mould, green or otherwise.

Humidity & Moisture

Do you have a towel radiator, or use heaters to dry wet clothing? Well… stop! Or at least, keep an extractor fan running and a window open when doing so. When you heat wet clothing or towels, you’re releasing the moisture in the cloth into the air. In fact, you can add up to 9 pints of excess moisture to your home by drying wet clothing.

This also goes for tumble dryers – they need proper ventilation. If you’ve forgone proper ventilation on your dryer, you’ll likely find a nice little colony of mould popping up near (behind) it. And one more tip – when you’re cooking or putting the kettle on, run your extractor fans (I’m saying it once again, for good measure). All of the steam that escapes your food and kettle has to go somewhere, and you don’t want to it stay inside.

If you want more information on where moisture can go and what might happen if it’s left unattended, check out our damp floorboards article. This is a great example of what happens when you leave moisture to do as it pleases, and is generally a great warning of the dangers of excess moisture in a home.

How to Treat & Test for Green Mould

There are a few things you can do to treat minor patches of mould. The “minor” qualifier counts as mould patches smaller than .9 square metres (10 square feet for the Yanks). First things first – you need to test your home for mould. While some patches may be obvious (green or black spots on the wall or skirting boards), it can also hide.

Take a walk around your home and look at specifically wooden structures near the floor and ceiling. Other popular areas for mould to grow include dark and damp areas, so basements are prime real estate for mould to make a home. You can buy a lab test kit to test for mould from most hardware and home supply stores. Sometimes it’s not mould, but another form of fungus. If that’s the case, you may need to call a professional for help. Additionally, if your mould patch is larger than .9 square metres, you’ll also need to give a pro a call. Now – how can you treat this invader?


Beyond specialised fungal treatments, there are four DIY solutions you can try. And as a note – wear a respirator while doing this to prevent inhaling any mould.

  1. Hydrogen Peroxide – Use 3% hydrogen peroxide mixed with water to eliminate mould. Spray the solution on the affected area, wait ten minutes, and wipe it away with a clean, damp cloth. Repeat as needed.
    1. Just like bleach, hydrogen peroxide can stain certain surfaces. Always test your cleaners on a discreet area first to ensure you won’t damage the surface the mould has grown on.
  2. Baking Soda – Combine equal parts baking soda and water in a spray bottle, and apply it to the affected area. Wait for ten minutes, and wipe away with a damp sponge until it’s no longer visible. Once the spot is fully dried, the mould should be gone.
  3. Vinegar – Mix equal parts vinegar and water into a spray bottle and spray it over the affected area. Wait an hour and wipe it away with a damp sponge. Repeat as needed.
  4. Diluted Bleach – Put 1 cap of bleach into a litre spray bottle of water and spray on the affected area. Wait ten minutes and wipe away with a damp sponge. Repeat as needed.

The reason we recommend using a damp cloth or sponge is simple. It acts as a moisture-rich alternative home for the mould! Be sure to discard the sponges once they’re used, and if you choose to use a rag, wash it thoroughly alone to rid it of mould.

Antifungal paint can also be purchased and applied after cleaning, but that’s a bit overkill in most cases.

Final Thoughts

Green mould on skirting boards or really any other area of your home is no good. Not only can it cause some serious health issues if left unaddressed, but it can actively damage your home. Allowing mould to sit and spread will only make your life worse – so address it as soon as it’s noticed. Mould and fungus can come in many forms, so be sure to test the spot before treating it to ensure it’s actually mould. If not, you’ll likely need to call a professional in to deal with whatever the issue actually is.

Once you’ve located the source of the issue, treat it with diluted bleach, hydrogen peroxide, baking soda, and/or vinegar. Discard of the sponge you use to wipe it once finished, and take steps to proactively prevent mould from reappearing. Allow for proper ventilation, run heat equally in your home, and use your extractor fans! If all else fails, give a professional a call and they’ll get things sorted for you.