Are you fed up with mold (mould) on your window sills? Or do you have unsightly mold around your windows? Tackling mold on your window sills is going to take time and you will need to be vigilant because mold is living and is always looking for places to set up home.
You want to get rid of the mold but just unsure what product to use or how to do it effectively?
Mold spreads, they release spores into the air, and these are difficult to get rid off until they set up a new home.
But do you know what kills mold? It isn’t as simple as you might think, some products don’t actually kill mold, bleach is one of these examples. It removes the colour and the surface appearance of mold but it doesn’t actually kill it so it will come back.

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Prevent Mold On UPVC Windows
Not only is mold on the window sills ugly but it can be dangerous to your health too!
Don’t let mold spores take hold in your home, tackle them and keep them at bay with these tips and ideas on what products to use and how to use them safely.
But don’t panic there are ways in which you can kill mold and reduce the possibility of it appearing and taking hold of your home.
Why Mold Grows On Windows
Mold develops around windows because of the difference in temperature from the inside to the outside and this causes condensation. Mold loves damp warm places to breed and grow, your windows are the ideal place.
We’ve created this problem for ourselves, we have a need to seal up our homes to reduce the potential of any energy loss.
The problem starts here; we then don’t ventilate our homes and any moisture is looking for a way to escape.
When the air laden with water hits the window, it forms window condensation, and this provides an ideal environment for mold to grow.
We have created homes with no air flow, we need this air flow to circulate around our home to prevent mold spores taking hold and starting up their own breeding grounds.
The Best Ways For Tackling Mold On Widow Sills
If you are looking for how to get rid of mold on window sills then you need to consider how the mold is taking hold. Are you providing it with the perfect environment in which to live?
As we’ve just discussed we need to make air flow, this will help to stop the mold from forming. You need to supply some sort of ventilation to the room with the problem.
Some windows come with ventilation built-in. This is something that we had to ask for when replacing our windows, it’s something that’s offered but not something they ask when they are designing your windows.

If you don’t have vents on your windows consider opening your windows, or having some sort of air movement, a dehumidifier is good even a fan causes air flow and this might be enough to reduce the potential for mold to grow.
What about a plant or two to help improve the air quality
Don’t seal up your home, let the air flow!
Prevent the growth of mold in your home.
Tackle This Mold Now
Getting rid of this mold is important, mould spreads by releasing microscopic spores into the environment and these spores can cause ill-health as well as new mold patches; it is not healthy to live with mold.
How you treat the mold will depend on how quickly it returns.
It’s very difficult to kill the roots of mold and most products just remove the surface colour and spores but leave the roots behind which means the mold will just re-grow and the problem to start again.
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Do You Get Mold On Glass
I have seen mold growing on my windows in the past, just tiny specks of mold trying to take hold.
If you want to know how to remove mold on windows, this is an easy process and simply wiping the glass with the cleaning product of choice will do the trick.
These spores that are released are looking for a home. They might have landed on moisture and decided to give living a go.
However, these are the easiest places to get rid of the mold because it can’t get it’s roots into the glass and any product that kills mold will eradicate these homes quickly and easily.

How To Get Rid Of Mold
You must keep on top of the treatment of mold and if you see it reappearing, it is important to tackle it again.
However, if you don’t aim to tackle the problem properly you will have to continue to deal with mold, spending money on cleaning products, whereas if you addressed the problem the mold should go away.
Getting rid of the mold is difficult the spores are in the air and they aren’t visible, and they can quickly take hold again and again. You must keep on top of the situation and don’t allow it to develop and grow where it becomes impossible to control and remove completely.
Living with mold isn’t something that you should even consider, it’s not good for your health and getting rid of it should be a top priority.
Tips To Remove Mold
When it comes to removing mold there are some items that you can use that will help to remove it completely and they don’t have to cost the earth either!
You want something that will kill the mold including the roots. Often, products aim for a quick fix and the mold will return because it’s just killing off the surface mold leaving the roots intact and ready to just start growing again.
- Bleach will not kill the mold on contact and is not an effective way to treat mold on any surface. If the surface is porous, the bleach is not an effective method to kill mold because it can’t penetrate the surface and kill the roots. Using bleach is great at removing the mold colour but you will have to keep reapplying regularly as it regrows. So, whilst it gets rid of the surface colour of the mold it doesn’t penetrate and kill the roots, allowing it to re-establish and re-grow.
- Borax is supposed to be great for cleaning mold but you do need to scrub the surface, and this will release the spores into the atmosphere and can spread the mold. I’ve been told that leaving the borax on until it is completely dry should eliminate the mold. However, this product isn’t widely available and in some countries, it’s banned, and for this reason I’ve never personally used the item.
- White Vinegar is a popular cleaning product for those people who are trying to avoid chemicals in the home, unfortunately, it doesn’t kill all forms of mold and this means it isn’t really an effective cleaner if you are looking to remove and kill all mold growth. This is a shame as I like using a natural product to clean with.
- Ammonia is not able to penetrate a porous surface and so some of the mold could survive and continue to grow. Whilst, it’s good for surface cleaning it’s not going to solve the problem long-term. It is important that you don’t mix ammonia with bleach as this creates a poisonous gas, this combination of chemicals makes a chemical warfare.
- Hydrogen peroxide is an anti-fungal product, which will kill the bacteria that it meets and is a safer product to use than bleach. Being anti-fungal it will kill the mold. This is good news as this product is relatively cheap to buy.
- Hot soapy water is the most ineffective way to kill mold, it can remove some of the mold, but it won’t kill the mold at all; what it will do is allow the mold to spread to new surfaces as spores are released into the atmosphere.
- Baking soda is a great cleaning product for lots of different cleaning tasks and one of those tasks is killing mold and absorbing the moisture too, making it a great treatment for mold as mould needs moisture to grow. However, it’s a very mild disinfectant and in some cases it might not be strong enough to completely remove the mold.
- Tea tree oil is the best treatment for killing and tackling mold on window sills, unfortunately, it is the most expensive option too. However, it can penetrate into the roots of the mold and can kill and remove all traces of mold. This is just one property of tee tree oil and is something you should have on-hand at all times.
Products Purchased For Mold Removal
If you were to look for cleaning products that remove and clean away mold you won’t go home empty handed.
But, do they work and how?
I’ve looked at a few products especially when it comes to mold as it seems to be a common problem but one that seems difficult to resolve.
If there was a simple remedy, then so many products wouldn’t be available.
I tried Astonish mold removal spray and I must admit it seems to work, the mold does go away but the product smells bleachy and this tell me that in some places the mold will come back.
It’s relatively cheap and if you are looking for a quick fix this might be the solution that you go for.
This company doesn’t test on animals and the product is vegan friendly.
Another product that is highly recommended but one I haven’t tried is HG Mould spray, this product is not tested on animals. I’ve been told is very good at removing mold, but it’s not one that I’ve tried.
There are other variations on the market of similar products but again I’ve not tried them, but beware if they contain bleach it might just be masking the problem rather than removing it completely.
- You might find this window cleaning article useful: When Did You Last Clean Your Windows?
- What are the best products for removing mold? Tea Tree Oil and Hydrogen Peroxide
- How To Get Rid Of Mold And Damp is a great article to read.
- Are you fed up not knowing what you need to clean and when? Do you wish everyone was on the same cleaning schedule as you? Now you can – grab my cleaning printable pack to help you organize your cleaning schedule.
- How To Clean Window Sill Mold is a great article to read but it does recommend bleach to clean with and I don’t think it will take the mold away completly.
- Check out these products on Amazon that might help you tackle your mold issue.
How To Remove Black Mold
Sometimes it might be appropriate to call in professional help especially if the mold is bad, there are some types of mold that are really dangerous to your health and you might need to ensure that this isn’t the case with the mold you have.
As you might have guessed there are different options all with varying results, but with all of them it’s important to follow the instructions and not to mix products.
You need to choose a product that will remove the mold, if you opt for a product that might not completely destroy it remember it’s going to come back. So, be prepared to tackle the mold again in the future.
Whatever product you are using protecting your health is key. So, if the product recommends wearing gloves then follow these instructions. A face-mask might also be required to prevent mold spores entering your body.
Think about protecting the area around the problem, you don’t want the product damaging anything else and you want to catch as many spores as you can. Something that can be rinsed or thrown away is an option to consider.
Depending on the product you are using you will want to let the product do it’s work before wiping and cleaning the area down. Most of the time product needs wiping away, you don’t want to leave the product on the affected area, do this carefully and avoid splashing the product on surfaces other than the mold.

How To Clean Mold And Mildew From Windows
I don’t want you to think that this is an easy project, especially if the mold has taken hold of the area. When you have a really bad patch of mold in reality it’s going to take more than one session to get rid of it.
If you don’t address the problem as to why you have mold in the first-place chances of it coming back are very high. If it’s around your window, often this is a ventilation problem and unless you take steps to address the issue it’s just going to come back.
Whatever product you are using I would wear protective gloves as a minimum. The first thing I do is spray the cleaning product onto the cloth. I don’t want the spray to allow the spores a chance to fly away.
Then slowly and carefully remove the surface mold. I swap cloths before going over the area a second time because I don’t want to re-infect the area with the fungus that is in the first cloth.
Wash all your cloths in hot water and I would add a drop of tea tree oil in to kill any spores that might still be lurking on the cloths.

How To Prevent Mold On Window Sills
Often, I’m asked ‘how to stop condensation and mold on windows?’ the answer is simple, mold loves damp warm places, and this is something that we create when creating sealed homes.
The condensation forms on windows because of the different temperatures and mold takes hold.
To prevent mold growth you need to remove the potential new home, this means proper ventilation, and tackling any mold as soon as it’s seen.
We had windows without vents and mold was a constant, I couldn’t keep on top of it, it drove me mad.
We recently had new windows installed and I insisted on vents on every window and we’ve had no mold. I know this isn’t a solution for everybody, but ventilation is the only way to prevent mold taking hold.
If the mold has entered a porous substance like sealant it’s more difficult to kill as you need to get into the root structure. Sometimes it’s easier to remove the sealant and to clean the area and reapply fresh sealant.
Preventing Mold Growth
Mold is a living organism and is looking for the most ideal place to live and grow. Prevention is so much better than dealing with the problem.
Ventilation is the most important thing that you can do, air flow prevents the perfect conditions from forming. If you still have a damp environment, then you need to think of other ways to dry out the area.
A dehumidifier is a good option, it allows the moisture to be removed from the air and this dries up the potential for having a damp room and can slow down the regrowth of mold.
Let’s Recap…
If you have mold on your windows already you need to find a product to get rid of the mold. Soap and water isn’t going to get rid of this, you will need a product that can get in and destroy the mold including the roots.
You have options, tea tree oil is amazing, but it is expensive. Hydrogen peroxide is another option that will kill the mold. Don’t use bleach on mold, it doesn’t kill it. The mold will grow back.
There are products that you can buy that are designed to kill mold, I’m not convinced that they are killing the mold completely because often the mold comes back.
But this could be that the environment hasn’t been changed and the mold can just take hold again.
Prevention is always better than curing the problem, look at the room and decide if there are any ways in which you can reduce the potential of mold.
Can you ventilate the room? Can you reduce the amount of water in the atmosphere to reduce the potential of creating the prefect home for mold?
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Misty says
Oh, we have SO had a problem with this. Thanks for sharing 🙂 Stopped by from Fellowship Friday
Sharon says
Thank you for visiting 🙂
cam says
We have this problem in a huge way during the winter. We have standing puddles of water in the window sills on cold winter mornings, and lots of mold to follow. I thought it was a problem with our windows (it’s a new house).
Bleach diluted in a heavy duty spray bottle works perfectly and easily to kill the mold, though I wish it never formed in the first place. I spray it on and leave it for a while, then wipe it all off. No more mold…at least not for a while.
Sharon says
Thank you for visiting, I think a lot of time the mould happens because we seal our homes up too well, we forget the airflow that prevents the mould growth. I think it is something that many of us have to deal with on a regular basis unfortunately. Thanks for taking the time to comment 🙂
Mary says
Was going to read the article, but something kept bothering me…. Oh, yes, it is MOLD not mould.
Sharon says
Hi Mary, Mould is the English spelling of the word and is therefore correct 🙂 But thanks for pointing this out I am only too happy to clarify any point in an article 🙂
elizabeth says
Thanks for the tips, very useful at this time of year, especially!
Sharon says
You are welcome! Thanks for visiting and taking the time to comment! 🙂
Stephen says
It’s “too” happy, not “to” in your sentence above. Spelling counts when writing for others. 🙂
Sharon says
Thank you for noticing! I have corrected it! Spelling is very important but sometimes an odd error slips through! 🙂
iris tregelles says
i moved in to a newly built home 2 years ago in the month of november and had awful mold by christmas. been fighting it until i discovered dehumidifiers are a marvel!!!! the one in my living room at my french doors i empty every 6 days of over a pint of water! and the master bedroom one next to the french doors there i empty it every 7 days of over a pint of water too! no more mold! gee wiz no wonder we had a mould problem all that water. dehumidifiers are the way to go.
Sharon says
I do love dehumidifiers but if the home has enough circulation of air then mould shouldn’t be a problem. It is a buy product of insulated homes! We have used and still do use dehumidifiers around the home but I want a more cost effective option! 🙂 Have a great week!
iris tregelles says
at the cost of 22p a week its a snip. my time is worth so much more. have a nice week:}
Carol says
It’s by-product, not buy product
Sharon says
Thanks for noticing I will update the post! 🙂
jean says
how do you use/apply the baking soda? I also have black mould/mold on my bathroom ceiling.
Sharon says
I just make it into a paste and spread it onto the mould, if you can leave it for a few minutes to work its magic the better results you will get. If you make a thick paste (use less water) and use a cloth to apply to the mould. Hope this helps!
Susan says
How do you use the tea tree oil?
Sharon says
Hi Susan, I just dilute a few drops in water in a spray bottle, shake well and apply. Nothing technical in my methodsI like to keep things simple! 🙂
Sarah says
Hello, Susan,
The caulking, paint and window casing of some of my windows are stained with mold. During the cold months they definitely produce condensation so I open the blinds & draperies, turn on the heat and the ceiling fans in those rooms to no avail. I’ve applied a paste of baking soda, hydrogen peroxide, five different essential oils known to be antifungal: 2 different tea tree oils (Melaleuca alternifolia & Melaleuca quinquenervia), rosemary essential oil, clove essential oil and cinnamon essential oil and have allowed it to sit then scrub with a toothbrush. Some of the staining is removed but not all. Would you suggest I use bleach for the staining then apply a light mist of the essential oils diluted in water or hydrogen peroxide to kill it?
Thank you in advance!
-Sarah
Sharon says
Sometimes I really hate caulking it is a nightmare for getting clean! You have certainly tried to tackle the problem and you have opted for some great products! Bleach should work for the staining, but it might damage the caulking! I would use a very mild bleach to remove the staining and rinse well before using a tea tree oil to kill the mold. To keep this from coming back I do fear that it is going to be something you will have to keep a very close eye on!
Lindsey says
Sharon, I love the way you deal with people! Set them straight in the nicest way possible. 🙂 And I love all the information on mould/mold killer.
Thanks,
Lindsey
Sharon says
Thank you for your kind words! I’m glad you liked the information too! 🙂 Thanks for taking the time to read and comment!
Sutton Turner says
I never knew that to stop the mold from forming you need to supply some sort of ventilation to the room. I had to get remediation done to my windowsill after mold piled up on it. Thanks for the tips for tackling mold on windows.
Sharon says
It’s such a simple tip but it works! Thanks for stopping by and commenting! ?
Paula Garcia says
Hi I have mold on the back of a vinyl poster. How can I clean it off so the rare poster is not damaged? Yes the wall is what caused the mold. Thank you
Sharon says
With anything that is delicate or rare is to take extreme caution. Because I can’t see the poster I would really be cautious as to how you tackle this problem! I would try to wipe it off with a cloth, if it doesn’t come off I suggest looking into a specialist to see what they say!
Sheridan says
I can’t believe how rude people are. This is a page with cleaning tips- not political opinions or slandering or anything even remotely malicious. It’s like a bunch of 13 year olds stumbled onto this page after their mother’s scolded them. Thank you, Sharon, for taking the time to post a page full of great tips and being very gracious and diplomatic when dealing with people. Let’s hope they learn a bit of humility.
Sharon says
Thank you for your kind words! ?
Kayla says
Thank you so much for these wonderful tips! We are currently renting a small farmhouse that was built in 1960 and it still has the original windows that slide sideways to open. All of the windows collect moisture and we have been struggling with mold issues. We have 3 small children (one of whom has asthma) so we have been looking for effective ways to rid our home of the mold.
Sharon says
I’m so glad you found these tips helpful! ?
Lix says
People do make spelling mistakes so quit complaining about how it’s supposed to be spelled, were interested on how and what to use to get rid of it not the way it is spelled!
Liz says
I agree people come on these sites just to criticize those that are trying to give helpful information to others. They need to zipper there mouths up and take a class on HOW TO SHOW CONSIDERATION AND RESPECT to others. They must be very unhappy people so get a life and be happy!
Elisabeth Southgate says
I appreciate you helping me learn more about mold. I didn’t know that bleach doesn’t kill mold. I wouldn’t any mold to come back. I might need to rethink what I sometimes use to clean up mold.
Olivia Miller says
The main reason behind the increasing the mold is moisture. Once mold comes in house people try to remove it by itself with bleach and another chemical. But they forget about all this thing contains water and when you remove it by bleach it gives more power to mold. So always avoid the bleach and other chemicals for the mold removal. You should take proper inspection of the house by mold inspector and start following step by step advice by the mold inspector which help to goodbye mold forever. If you take the right step then a mold isn’t a big problem. Cheers!!!
One Day Glass says
the facts have been discussed is really important. Thank you so much for sharing a great post.
John Smith says
Thanks for sharing the ways to protect window sills from molds. I was not sure what products to use and how to do it effectively.