How To Get Rid Of Mold From Garage Walls? (4 Super Helpful Ways!) is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to . The website is also an affiliate of a few other brands.

Mold growth on garage walls is very distressing, yet a common occurrence. Mold needs an organic food source, high moisture, some warmth, darkness and poor air circulation to thrive. Your garage walls often provide all these. So how to get rid of mold from garage walls?

To get rid of mold from garage walls you need to:

  1. Understand Mold & Mildew – there are many types
  2. Be on the Lookout for Mold – before it covers a large area
  3. Get Rid of the Mold Spores – the sooner the better
  4. Take Preventive Action – you do not want them coming back

Mold spreads fast! So you need to act fast too!! Get rid of mold from garage walls, as soon as you see the first signs of mold growth. 

So let’s get started!

What are Mold & Mildew? Understanding the Difference!

Mold & Mildew are often mentioned together. They are very similar, but do have some important differences.

Between the two, mold is a more serious problem and can be more damaging to your health.

Both mold and mildew are fungi and have the same basic requirements to thrive.

  • Organic food sources such as wood, textiles, paper etc.
  • High humidity or damp, wet surfaces
  • Some warmth
  • Dark, dingy lighting conditions
  • Poor air circulation
Get Rid of Mold on Garage Walls


Mold is green or black with a fuzzy or slimy texture. Mold is usually seen on the wall surface but it can grow inwards too, especially in porous wall sheathing surfaces such as drywall. Mold can destroy entire drywalls, requiring complete removal and replacement.

The adverse effects of mold on human health can include respiratory issues, such as asthma, heart problems, joint pain, migraines, fatigue and depression.


Mildew is typically white, gray or yellow with a fluffy or powdery texture. Mildew will remain on the wall surface. Mildew is easier to clean and will not cause lasting damage to the surface that it grows on.

Its effect on human health is also relatively milder. Inhaling mildew can lead to coughing, breathing difficulty and headaches.

What are the First Signs of Mold on Garage Walls?

In your war against mold growth on garage walls, you have to be vigilant at all times. You have to inspect your garage walls regularly so that you can spot the first signs of mold growth on your garage walls early on. 

Mold spores are in the air, everywhere, all the time.

All they need is to land on the garage wall that will provide them with food and water. They may become visible in a couple of days. Within a week you will have an outbreak.

Since mold grows in dark corners they are difficult to spot. You are likely to smell mold growth, even before you see it. If mold or the mildew are present and thriving in your garage, you will notice the unmistakable musty smell associated with them.

Humidity is a factor in mold growth that can change significantly in your garage due to condensation, water leakage, rain, flooding etc. So you have to do a more thorough inspection of areas that are prone to high moisture and after heavy rains or garage flooding.

Some areas that are more likely to encourage mold growth are

Keep an eagle eye on these spots.

How to Get Rid of Mold on Garage Walls?

You need a slightly different technique to get rid of mold from your garage walls, depending on the type of wall and the extent of growth.

In all cases you must

  • Wear long rubber gloves, safety glasses & N-95 respirator. These are the most basic personal protection equipment (PPE).
  • Wear long sleeve shirts & long pants (which should be washed in hot water after the job is done). This is to protect your skin.
  • Cover the floor and surrounding areas with plastic sheets (which should be discarded after the job is done). This is to ensure safe and quick clean up of mold spores.
  • Ensure proper ventilation in the work area. You do not want to breathe in the mold spores.

How to Get Rid of Mold on a Painted Garage Walls?

It is relatively simple to remove mold from painted walls, but you need to do it the right way.  

Remove everything around the affected area and lay a plastic sheet on the floor. Mold spores can get airborne and migrate to another area of the garage. You don’t want that.

Mix some dish washing liquid soap with warm water. Use this solution and a rag to clean the garage wall with mold growth. This does not kill the mold. It just makes the next step easier.

You can use any mold cleaner spray available at the store. You can also make it at home by mixing one part bleach to three parts water. A milder version uses one part of baking soda in five parts of water. Spray this on the mold and wipe clean with a rag.

Then spray again and wait for 10 minutes. Scrub with a soft stiff brush to remove the mold. You may have to repeat this process if the mold growth is deep seated. Finally wipe clean with another rag.

Wash the painted wall with clean water and let it dry. Use a fan or a blower, if required.

XPOWER 1100 CFM Industrial Axial Air Mover

XPOWER 1100 CFM Industrial Axial Air Mover

For quick drying and ventilation during water damage restoration projects turn this powerful and versatile industrial axial fan.

Touch up the area with stain blocking primer & paint.

How to Get Rid of Mold on Plywood or OSB Garage Walls?

A garage wall can sometimes be made from plywood or OSB sheathing. Plywood, OSB, MDF etc. are organic building materials (made from wood) and are also hygroscopic (will absorb moisture). 

If these have been painted or stained, then the paint or the stain will act as a moisture barrier. High humidity, condensation or even occasional flooding will not result in water penetrating the plywood. 

Mold growth will likely be on the surface only. You can get rid of the mold on painted or stained plywood, by the same way, that you would use to get rid of mold from a painted wall.

But if the plywood was not painted and there has been some leakage or flooding in the garage, then the plywood would have become moist. The mold which starts off on the surface can grow inwards and take root.

In most cases you will be able to kill it using distilled white vinegar solution, rather than bleach or baking powder solution. If some spots remain, you could lightly sand the area to remove the mold that has penetrated the surface.

How to Get Rid of Mold on Drywall Garage Walls?

Drywall is basically powdered gypsum held together by two sheets of paper, like a sandwich. The paper is the food for mold and it basically grows on it. 

The bottom end of the drywall in a garage wall is most prone to getting wet as garage floors can often have water pooling.

The paper, visible to you, can get wet due to condensation or high humidity in the garage. Mold will start growing on this. If you detect it early, you can use a standard chlorine based mold cleaner or a bleach solution. They work fine for surface mold.

But they can not penetrate. So if the mold is in an advanced stage, then it is likely that the mold has gone deeper. You then need to use undiluted white vinegar. Vinegar has a strong odor, but don’t worry. It will dissipate with time

In case of flooding or leakage, water will penetrate into the drywall because of the porosity. Actually even to areas beyond the flood or the leak, because of wicking.

So the paper on the other side would be wet too and mold can grow where you can’t see it.

In this case you will need to remove the affected section of the drywall. Bag the cut out piece and dispose. Make sure it goes off in the garbage and does not leave any spores in the garage. Replace the cut out part with a new drywall piece.

If the damage is more extensive, you may have to change the entire drywall. Consider getting in the specialists at this stage. Also consider using a less porous, mold resistant building material.

Check out my blog post The Best Alternatives & Add-on’s to Drywall for Garage Walls for some ideas.

How do you Keep Safe while Cleaning Garage Mold?

Mold spores will get airborne during cleanup. At the very least they will cause irritation in the eyes, nose and throat. Persons with allergies & respiratory diseases such as asthma should avoid participating in mold cleanup, if possible.

The following Personal Protective Equipment (PPE) should be used during cleanup.

  • Wear clothing that covers your entire arm & legs. Make sure to either discard or launder the clothes worn during mold cleanup
  • Respiratory mask
  • Latex gloves
  • Protective safety eyeglasses with side shields

How to Prevent Mold Growth on Garage Walls?

Mold spores are in the air, everywhere, all the time. You can’t do much about that.

Food for the mold in the form of organic building materials such as drywall, plywood, wood or paint are part of the garage. You can not eliminate these. 

But you can take some steps to reduce some of them. For example, you could use cement boards instead of drywalls.

Control of moisture, however, presents the biggest opportunity in preventing mold growth on your garage walls.

“Molds are part of the natural environment, and can be found everywhere, indoors and outdoors. Mold is not usually a problem, unless it begins growing indoors. The best way to control mold growth is to control moisture.”


Keep Humidity Low in the Garage

Your garage can have a high level of humidity, condensation, water seepage, water pooling or even flooding. You need to stop all these from happening. You have to keep your garage dry to prevent mold growth.

Humidity in the garage can go up if the humidity is high outside. This is quite common during the rainy season or if your house is close to the sea or a large lake.

Humidity can also go up if you wash your car in the garage. The way to combat high humidity is by running a dehumidifier in the garage. A garage dehumidifier can help suck out the moisture in the garage air and bring humidity to acceptable levels.

Honeywell 30 Pint Dehumidifier

Honeywell 30 Pint Dehumidifier

Reliable and precise, these Honeywell dehumidifiers are perfect for rooms up to 400 square feet. Choose the wi-fi upgrade for control of your humidity from anywhere.

For more information on humidity control check out my blog post How To Make Sure Of Best Climate Control For Your Garage

Prevent Condensation

In cool weather, especially during night the temperatures outside drop. The garage door, the walls and the concrete garage floor gets pretty cold too!

However, the air in your garage is still warm. Mostly warm because of the heating that you have installed in the garage. But even without heating, the air is warm from the day before. 

When warm air from the garage meets the cold surfaces, condensation happens. A thin film of mist forms on the garage door, walls & floor. This is enough, sometimes, to promote mold growth.

You can prevent condensation, by better insulation and air circulation within the garage. For more information check out my blog post How To Make Sure Of No More Damp Garage Floors

Improve Garage Drainage

Your garage floor can get wet because of rain water or snow melt. The water may come in along with the cars when they come or it may flow in from the driveway.

Your garage floor should slope outwards so that any water that pools can flow out naturally. However, this may not always work. 

It is best to have a drainage system in the garage to clear the accumulated water quickly. This will ensure that humidity levels are in control and the drywall will not get wet.

Learn more from my blog post Simple and Easy Guide to Best Garage Floor Drain Solutions

Garage Floor Water Diverter

The fight for keeping your Garage Floor dry during the rainy & winter months requires you to incorporate four strategies.

  1. Prevention – Keep the Water Out
  2. Diversion – Move Water Away
  3. Containment – Limit the Water Spread
  4. Clean Up – Get The Water Out

To move water away, a Garage Floor Water Diverter is an important weapon in your arsenal. The technique of moving the water away from the garage floor and into the storm water drain or drain to daylight is essentially the Garage Floor Water Diverter technique.

You can install drains on the driveway and inside the garage. You can also use drain tiles. Find out more from my blog post How To Make Sure Its Dry? Garage Floor Water Diverter Is Helpful!

Waterproof the Garage Walls

To keep the garage walls dry, you should waterproof them. The best time to take care of waterproofing the house foundation is at the time of construction.

However, if this has not been done or is ineffective, then you can do it again. However, make sure that you “waterproof” and not just “damp proof” the garage walls. 

This involves digging up the soil outside the garage to expose the entire foundation and a few inches of the footing. The entire foundation wall from say 6 – 12 inches above the soil level to the bottom of the exposed footer level should be coated liberally with Liquid Rubber.

A perimeter drain or French drain is made. It collects all the rain water and keeps it at a level below the foundation wall and footer joint. The water is diverted away from the walls to the storm water drain.

To know the full details of the process read my blog post The Best Way of How to Waterproof Your Garage Walls

GMS Intro

GMS Intro
GMS Intro

Thank you very much for reading the post. I do hope you found it informative and useful.

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