How To Remove Black Mold On Deck Wood? – A Step-By-Step Guide

Woods are one of the most commonly used materials for decorating, furnishing, and other works. It is also the same thing, which is hygroscopic. This means it absorbs water and moisture from the air, the rate of which is 6-8% approximately.

This feature of wood attracts various germs, bacteria, funguses, and viruses to rot it gradually. Therefore, it is necessary to protect it from these molds, grimes, filths, and stains. Among all this, Mold infestation on wooden decks is the most concerning issue. So, how to remove black mold on deck wood?

And if the weather is shady hot, humid, cold, and wet, it becomes hazardous. Besides, it can cause great havoc if you don’t remove black mold on deck wood immediately.

Here is the precise solution of removing black mold on deck wood; you might be browsing by now. But before that, know what this black mold is, the pros and cons, the danger of it, and the prevention.

How To Remove Black Mold on Deck Wood?

What Is Black Mold?

What is Black Mold

Did ever black stains or spots on woods, pipes, old building sites, decaying leaves, cardboards, and sometimes on foods crossed your sight? If yes, then didn’t you think, “What are these black spots”? Are they removable? OR how to remove black stains from wood deck?

Well, you can stop the brainstorming, as the answer is here. These are black molds. It is removal. And there are so many processes to remove it. For now, see the details thoroughly. Black mold is a kind of multicellular microfuges. It is a toxic mold, which is scientifically known as Stachybotrys Chart arum. It can spread its spore and produce conidia in any kind of material.

Highly cellulose-based and damp materials are the victims of it. It can be identified by dirk greenish circular marks or black spots on deck wood. For, woods get wet or moisture easily; they attract the attention of black molds shortly. Researchers have proclaimed that it is toxic and sometimes can infect the pulmonary organs, but it is too hazardous for the human world. Besides, it does not impact much on the nature of the quantity is less dense.

Types of Black Mold

Types of Black Mold

Several types of black molds with varying landmarks such as Alternaria, Aspergillus, Cladosporium, Purple Mold, Stachybotrys, etc. These differences are based on toxicity, so one should understand the urgency of abolishing black molds from deck wood or any other material.

Alternaria is the less notorious black mold, growing in outdoor things. It is an allergenic mold with 300 existing species in the world. Also, it has a remarkable dark blackish velvety texture, which can rot wood indiscriminately. It can be removed using a non-toxic fungicide or prevented by proper air ventilation indoor with HRV (Heat Recovery Ventilation).

⦁ Aspergillus
Aspergillus has a powdery texture with its 200 species, among which 16 are marked as threatening. It is otomycosis that generates ochratoxins and isoflavone ororbol to damp woods, building materials. Aspergillosis, Pulmonary acute or chronic diseases can be infected through it easily. Hence, it should be dealt with professionals rather than personal activities.

⦁ Cladosporium
Cladosporium is a comprehensive indoor and outdoor growing black mold with almost 40 familiar and 180 unfamiliar species. It can cause black spots on deck wood, an eyesore, sinusoid problems, skin rashes, etc. Registered non-toxic fungicides such as Concrobium can eradicate it from the root.

⦁ Purple Mold
It is a color variant of black mold, which easily confuses people. And, if it is seen on any wooden deck or wooden surface, it is most likely the Phanerochaete Crassa type. It has a destructive force on wood. Besides, it can also crush the wood from celling or decks, which can be risky for home and outside.

⦁ Stachybotrys
Black or greenish-black color most toxic molds are Stachybotrys Chartarum. There has been an alarming rate of deaths in the United States for this. It produces mycotoxin, which makes the woods rotten and damp. Sneezing, headache, blood-poisoning is also the effects of it. Professionals must treat this type of poisonous mold.

Why Does Black Mold Grow on Deck Wood?

Why Does Black Mold Grow on Deck Wood

“Prevention is better than cure.” So, It is better to know why black molds grow on deck wood and keep it mold-free than removing molds from it. Again, it is costly and bad for normal health.

It takes 1/2 days to colonize and produce spores on wood. For, other variants the time may differ from 7/12 days. The growth rates of any kind of molds depend on their growing environment. Reasons for Black Mold Invasion on Deck Wood There are so many reasons, particularly for black mold growth. Few threatening causes are given below-

⦁ Moisture
For black molds to grow and produce spore, moisture is the undeniable part. Without which it can’t stay longer on the woods and other materials. As a result, it can easily be removed and cause less harm. Black mold breaths in moisture from humidity, rain, air conditioner, dryer, etc. The reproduction rate of black mold depends on the concentration of air most of the time. The more moisture it gets, the more benefits it gets.

⦁ Warm ambiance
Heat is the second most important element for the existence of black molds. They can bear up to 73°F to 104°F temperature. And it can survive even when the temperature gets down to 36°F. Temperature works as an adamant feature for them to live longer. Furthermore, it adds up the production rate of spores and spreads them rapidly.

⦁ Shade or less lightening
Black molds, for their best growth, needs little light or shady areas. However, it can manufacture spores on dark accommodations too. A little amount of light carries oxygen for it to live, while excessive light with ultraviolet rays can demolish it.

⦁ Adequate time
Black molds are life-taking, and so it needs much time in contact with water to generate. If the woody things are kept wet for long hours, like 24-48hrs, it may help it grow molds on it.

⦁ Humidity in air
It needs humid air to germinate at the beginning. The approximate rate of which can be 70% – 90%. After proper breeding, it can circulate uninterruptedly

⦁ Improper Ventilation
Black mold thrives in poorly ventilated places. As these types of places are easy to go for being heated and frozen, humidity gets stuck. And it results in surface moisturizing of woods, celling, and other surfaces. This type of insufficient ventilation can also cause the slippery or wet areas to dry hardly is another cause of mold infiltration.

⦁ Stain duration
As long the stains stay on wood, the longer it draws the attention of molds. Stains cover the area for being dampish. Or in another word, it protects the area from being dried up. It may result in acceleration of mold expansion. Any kind of stain, oil-based or water, holds the power of mold generation. For now, when you’ve already known the reason behind black mold growing, know about the dangers as well. So, you stay alert before losing everything.

Why Is Black Mold Dangerous?

Why is Black Mold Dangerous

Black mold is not only dangerous but also life-taking in some cases. If you feel any sign of black mold in your surrounding, don’t think twice to get rid of it. It varies on the effectiveness with running time. Some troubles and threats are discussed below-

⦁ It hits on our physical health by exposing mycotoxin continuously in the air. We breathe in the air, and our Respiratory organ starts behaving abnormally and causes asthma, pneumonia, and other bronchial diseases.

⦁ Acute disposal of toxins faints our neurological senses by damaging our optical, oculomotor, olfactory, etc., nerves. Sore eye, runny nose, skin rashes are common facts executed by molds.

⦁ Memory loss can also be caused if the duration of black mold extends. It can also turn into premature deaths.

⦁ For pregnant women, black mold invasion is very bad news as there’s the possibility of miscarriages and genital diseases.

⦁ Statistics states black molds are responsible for undetectable illnesses and untreatable diseases as well.

⦁ It destroys whatever it touches. For instance, woods, pipes, buildings, and anything drenched with moisture or water for a time length.

⦁ Last but not the least, it can cause bad headaches, blood-poisoning, callousness too. Therefore, precaution is the ultimate solution for it. But before that, one should know how to identify it.

Signs of Black Mold Existence

Signs of Black Mold ExistenceSigns of Black Mold

Dark and Black circular spots
It is the beginning state of black mold. With time it gets darker, extended, and heinous.

Strong sour or musty odor
It may not bother the one living in the house for a long period. But others must be disturbed as soon as their smelling sense gives them a musty smell. But this severe smell comes slower than the spots.

Dampish surface with odd colors
If you’ve checked through the types of black molds already, you can certainly recognize it. Sometimes it may remain invisible by not being on the surface. This difficulty can be solved through smelling and other signs.

Raise of allergenic illness
Suddenly, you will feel that the reaction of your allergenic sickness has increased. And, it is for none but black molds. Start searching throughout your home.

Struggling in respiration
Respiratory syndromes are the supreme results of overgrowing black molds. In such cases, try to ask for help from professionals. Now, when you have clear notions of Black Molds, you can easily identify them. If the results ensure you about black mold, read the next context.

How To Remove Black Mold on Deck Wood? – Follow Ways

How to Remove Black Mold on Deck Wood Follow Ways

Removing black mold from deck wood is an important maintenance task to ensure the longevity and safety of your outdoor space. Regularly inspecting and maintaining your deck can help prevent black mold growth in the future. Remember. Here are some steps to help you effectively remove black mold from your deck wood:

1. Safety first: Before starting the removal process, make sure to wear protective gear such as gloves, goggles, and a mask to avoid any potential health risks.

2. Prepare the area: Clear the deck of any furniture or plants and sweep away any loose debris or dirt.

3. Mix a cleaning solution: Combine one part bleach with three parts water in a bucket or spray bottle. Alternatively, you can use a commercial deck cleaner specifically designed for removing mold and mildew.

4. Apply the cleaning solution: Use a brush or sprayer to apply the cleaning solution to the affected areas of the deck wood. Make sure to cover all visible mold spots thoroughly.

5. Let it sit: Allow the cleaning solution to soak into the wood for about 15-20 minutes. This will help loosen and kill the mold spores.

6. Scrub the surface: Use a stiff-bristle brush or pressure washer to scrub away the mold. Start from one end of the deck and work your way towards the other end, focusing on small sections at a time.

7. Rinse thoroughly: After scrubbing, rinse off the cleaning solution and loosened mold using a garden hose or pressure washer on a low setting. Make sure to remove all traces of bleach or cleaner from the wood.

8. Dry completely: Allow the deck wood to dry completely before applying any sealant or stain. This will prevent further moisture buildup and reduce the chances of mold regrowth.

⦁ By Using Household Things

Cover the spotted area with a tape or plastic sheet to not flow in the air and infect other parts of the house. Purify the area with a scrubbing brush dipping it into soap water. You don’t need it. Pull it dry, rather scrub it gradually. Pick a tray or plastic bag and get rid of all wastes and infected materials. Make sure to throw it somewhere safe without causing trouble to others.

Use any kind of strong disinfectant on the marked spot after cleaning it properly. You can use detergents, white or distilled vinegar, hydrogen peroxide, tea tree oil, etc. Never use them directly; mix them well with water and then spray them over. Let it dry. Make proper ventilation. You can use a fan or dryer or anything suitable for you.

Tips – Woods that can’t be dried or cleaned, it is better to discard it.

⦁ By Using Borax

If the household things do not work, buy Borax from any shop. Make a solution of Borax with plain water and 1/2 tablespoon of borax powder. Mix it well and use it with a brush; avoid using it directly by spraying.

Scrap it away, don’t wipe it. When the molds are out, use a dryer and dehumidify the area; let the Borax sit on the wood. Borax is an alkaline group minerals salt, safer to use than bleach. It will stop the black molds from further breeding forever.

⦁ By Using Oxygen Bleach

By Using Oxygen Bleach

Bleaches are great agents working as cleaners, but precaution should be maintained before using them. Mix it well with water. Then let the mold on deck removal lay for few minutes. Scrap it away. Never mix any detergents or ammonia-based chemicals on it.

⦁ By Using TSP

Trisodium Phosphate is an industrial level cleaner that reacts, breaking the phosphatic bond and releasing the sodium. Make a solution of it using 1.5 cups of TSP and then use. It has bad impacts, so use it carefully.

⦁ By Using A Vacuum Cleaner

By Using a Vacuum Cleaner

A vacuum cleaner can also be used for easy cleaning, but it may not be fruitful all the time. If the molds are penetrated deeply, it may become difficult to get them out. However, if you are using this process, then use a HEPA filter on the vacuum. Clean it; scrap the molds on a plastic bag for refraining from further diffusion.

⦁ By Using Deck Cleaners

By Using Deck Cleaners

Using a chemical deck cleaner solution can be more fruitful than overall steps. But, yes, it is expensive. You can use WET & FORGET 10587 moss mold mildew & algae stain remover.

These products are made with particular chemicals that are most reliable for deck cleaning. Again the cleansers are quite easy to use. This cleanser cleans the deck woods, wholly leaving nothing behind. These mildewcides are most reliable as it ensures the molds removal forever, leaving no doubt of further mold infestation.

⦁ By Using A Pressure Washer

By Using a Pressure Washer

Using a pressure washer will cause you less labor and surprising effectiveness. The pressure washer removes the molds with a brightening impact on them. One can never know if it was infected by molds once. It can crush the softwood, but sometimes they are used for the force of clean. Remember to using it with proper knowledge.

With The Help Of Professionals

If you are doubtful about black molds’ location, you should see a professional to do the job. While handling something so toxic, I would rather suggest taking experts’ help. Again, if the area is too much contaminated with black molds, you have no choice but to call them for help.

The EPA gave recommendations on the mold that, “if the mold expansion extends the length of 10 square feet, you must have to call the professionals for your safety”. Experts know better ways, tools, and concepts of removing things without harming the environment or your house. Make sure you hire someone who is IICRC Certified.

The removal is done. But are you still carefree? Don’t you think they can attack your households again? If this concern bothers you, keep on reading.

How To Prevent Mold On Deck Wood?

How to Prevent Mold on Deck Wood

Removing is not the only way to get rid of black molds; they can regenerate soon. After recovering, you’ve to ensure full elimination of molds from your abode by keeping them clean, dry, and moisture-free. There are some mandatory steps you must follow to keep your home always mold-free.

⦁ By Using A Sealer On Deck Wood

By Using a Sealer on Deck Wood

On deck wood, sealing can work as a barrier for molds, water, and moisture. Water-based and mold-resistant sealers can get you more benefits.

In the Rainy or Winter Season, when the rainwater or snow clogs on the wood, the sealer protects it from deep penetration and helps to dry fast. It works as a protection layer or surface for a year; then, you have to seal it again and redo it like this.

⦁ By Keeping The Room Air Moisture And Humid Free

Always try to keep your room fresh with air and sunlight. Proper sunlight keeps the woods dry and germ-free. Make sure the humidity rate is not more than 50%. If you use the air conditioner, clean it daily.

⦁ By Maintaining HRV

Heat Recovery Ventilation can help in this matter. It will control the air temperature and control heat of your room. Also, you can use air-purifying machines in your bedroom and a ventilation fan in your kitchen. And if it’s unaffordable, keep your windows open so that the air can go in and out.

⦁ By Keeping The Deck Clean

By Keeping the Deck Clean

Cleanliness can work as a miracle against black molds. Keep your desk neat and clean regularly. But don’t use wet clothes to clean. Try to maintain great hygiene indoor and outdoor too. Disinfectants can be helpful in this matter.

⦁ By Shoveling Snow From Deck Wood

Winter snow is dreadful for wood, as it can cause it wet and dampish effect. And this effect is the ideal condition for toxic black molds. Therefore, shovel your woods to save from snow and fog clog.

⦁ By Using Chemicals

Instead of keeping your deck wood bare and open for mold invitation, use particular chemicals on it, such as Didecyl Dimethyl Ammonium Chloride, Chlorothalonil, and Mildew-X, etc. After every 3/4 months, check your home, deck, and furniture’s thoroughly to be rest assure of mold invasion. The more precaution you take, the safer your abode will get. This will cost you less labor and less money as well.

What Kills Black Mold On Wood?

There are numerous ways to kill black mold on wood. One just has to consider the best method appropriate for them and the environment.

⦁ Baking Soda
Baking soda is a Bicarbonate sodium crystalline powdery salt, which with water makes base and acid. Base kills and cleans the mold, while acid prevents it from re-growing. Make a paste of baking soda and water; use a brush to stick it on mold. Let it stay, and then scrape off. Use baking soda and water again to make a solution and spray on the cleaned spot. This will stop mold regeneration.

⦁ Extracted seed of Grapefruit
The extracted seeds of Grapefruit contain polyphenol compounds that carry Limonoids and Naringenins, working as a disinfectant against fungus, algae, and bacteria. It also kills and prevents mold breeding like baking soda.

Use 8/10 drops of the essential mix well with every cup of water, spray it on the affected area, then wait for minutes or hours. Take as long time as you think it Is necessary or how deeply the molds are attached. Finally, wipe it away.

⦁ Juice of Lemon
This is a citrus acid-based killing process. Squeeze as many lemons as you need for juice. You can use it with Luke warm water or shampoo or detergent for better use. Let it seat on it for few minutes. Wipe it away or can brush it too.

⦁ Wood Sanding
If the molds are not too dampish and dry, use 100-grit sandpaper to rub it well and clean the mess with a vacuum cleaner. Then pour out all the waste on a container bag to dispose of it.

⦁ Consortium Mold Control Spray
Use the Consortium spray on the molded spot, let it dry. And clean the surface using a consortium wet cloth or a scrubber to clean it. When it gets dry, spray the solutions again as a further restriction for mold growth.

⦁ Hydrogen Peroxide Complete Mold Killer and Remover
This killing remover is a 3 in 1 solution working against bacteria, fungus (mold), and viruses. Use this spray with water, and the proportion will be 1:2. Then all the same process again- let it stay, dry, then wipe or rub out. Apply it one more time for creating a protective layer, or you can say sealing layer.

Tips- Never use any chemical directly on your deck. It can harm the surface or discolor the wood. Mix it with water before use.

How To Remove Mold from Pressure Treated Wood?

How To Remove Mold from Pressure Treated Wood

Before knowing how to remove mold from pressure-treated wood, we have to what pressure-treated wood is actually! To preserve wood from degradation, chemicals are used on it. The chemicals pressurize the woods from infesting molds and mildews.
It is not the old way of structural wood preservation. Hence, this way, the woods last for a long duration, without maintenance for periods. Still, these pressure-treated woods can also get infected through molds. After a long preservation period, molds can breed on it. So, there are several ways to remove it.

⦁ Scrub it off gently using a nylon brush or any soft one. This is the easiest way mold removal.

⦁ Soaps can also be used for this purpose. Scrap it off using soap and water.

⦁ You can also use a commercial wood cleaner with lime water in the same way.

Tips- Despite wiping after cleaning, use any power washer or pour hot water on it. And it is a better way to use organic fungicide than any harsh chemical compound.

How To Remove Mold from Stained Wood?

How to Remove Mold from Stained Wood

Stained wood does not need much attention provided that they are painted or stained properly in the first place. Nevertheless, if the circumstances occur, you have no choice but to clean it. Use a dishwasher or soap water or vinegar on it, and then wipe it out slowly. Don’t be too harsh; it can harm your painted wood, causing mold intrusion.

Tips- Skip using bleach and a pressure washer on stained wood because it may create holes on the surface of stained wood, which can cause mold penetration easily.


To keep your house in good condition and remove black mold on deck wood is not an easy task. But, if it is not taken care of in the right measure, a living span of things can rise. This is your home and your concern to make it livelier and mold-free for sure.

Therefore, it needs more knowledge about things that can harm your livelihood. Though a little amount of mold is good for nature, its disadvantages make it more highlighted.

Be careful while dealing with molds, know what it is, how many kids are there, how you can know if your decks are affected or not, how to get rid of them, and how to stop them from further interruption.

You should also beware of how to remove mold from outdoor wood as well. Try to follow the tips and ignore what harmful even a bit is. I hope now you know how to remove black mold on deck wood.

Frequently Asked Questions (FAQs)

1.How do I remove black molds on deck wood?
Ans. There are certain ways of removing black molds. But I prefer the easiest, Deck cleaner process. I pour the cleaner on molds. Let it stay for moments, then wipe it off and scrap it in a plastic bag.

2.How do I remove black molds with less money?
Ans. There’s some time when I also look for a cheaper way to remove black mold from my houses like the household dishwasher, mild detergent, or a mixture of soap and warm water. You have to give little effort to save your money.

3.What should I do with obstinate black molds?
Ans. If it seems impossible on your behalf to remove black molds on your own, seek professionals help. They can locate, guide, and use the correct tools without harming your things.

4.Will Wet & Forget Can help me to remove any kind of molds?
Ans. Yes, I’m optimistic about this. It is a deck cleaner especially made for removing molds, mildews, and fungus.

5.“Bleach or Pressure washer” which one is more preferable for cleaning black mold?
Ans. Pressure washers can be more reasonable for they are easily available. But it’s suggested to use bare woods for more benefit. They can forcefully wash out the molds leaving no stain.

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