Does KILZ Kill Mold: What You Need To Know About Kilz Primer

Finding patches of mold growing on your walls is the last thing you need, and dealing with it can sometimes be a hassle, so, is Kilz paint the answer to your prayers? Can you simply paint over the mold and no longer worry about it, or is there more to the story?

In this article, we will be fully explaining whether or not Kilz paint actually can kill mold, or if you’ll need to take extra precautions.

So, for all you need to know about the efficacy of Kilz paint in killing mold and mildew, keep reading.

What is Kilz paint?

Kilz paint is a water-based primer and paint used for both indoor and outdoor surfaces. It has minimal scent and once dried, can be cleaned without being damaged, as well as being resistant to stains, scratches, and peeling, and comes in a preparation that makes it resistant to mold.

Can you paint over mold using Kilz?

Whilst it is possible to paint over mold using Kilz, this is not advised, as untreated fungi will continue to grow under the paint and eventually start to show through the paint and may begin to grow a new colony.

The paint will of course cover the signs of mold for weeks or potentially even months, but underneath, a large colony could be forming, ready to break through at any moment.

Will kilz actually kill the mold?

Unfortunately not, despite its name, Kilz paint will not actually kill any established mold that it is painted onto. Instead, it has an EPA-registered active ingredient that creates an efficient mold and mildew-resistant film, preventing any further growth on the surface.

Any pre-existing mold that is painted over will continue to grow unless the underlying reasons for its growth are addressed. This may explain some people’s frustration after having painted over mold, only to find that it continues to grow.

How do you use Kilz?

Whilst we have discussed the fact that the paint will not kill or remove an existing mold or mildew issue within a property, it is an excellent way of preventing further outbreaks once the underlying problem has been resolved.

Use the following steps to use Kilz paint to effectively prevent mold growth in your home or property.

Address the underlying issues first

As stated, if the underlying condition causing the growth of mold is not dealt with, covering it with Kilz paint will not solve the problem.

Addressing the issue may include looking for leaks, high moisture areas of the property, or evaluating airflow. Should you find that the room that has been suffering from fungi growth has poor airflow for example, address this issue before moving on to the next steps.

Step 1. Clean the wall

Pour undiluted white vinegar into a spray bottle, and spray liberally on the areas affected by fungi growth. Leave the vinegar to work for a minimum of 1 hour before wiping it away with a clean, damp cloth. Repeat this several times if necessary to kill and remove all mold, and allow the surface to completely dry before attempting to apply any paint.

Step 2. Apply the primer

If the surface you are looking to cover has been badly stained by years of mold growth, a layer of primer will help to prevent this showing through the top coats, oil-based primers will hide stains more efficiently than water-based versions. Apply the primer to the wall using a roller and leave to fully dry.

Step 3. Apply Kilz paint

After stirring the paint, use either a brush dipped into the can, or a roller on a tray to apply the paint to the surface, using even strokes.

Step 4. Allow plenty of time to dry

Depending on the temperature and humidity of the room you are working in, the paint may be dry to the touch within 2 hours or may take up to 5 hours in colder temperatures.

Step 5. Apply a second coat (optional)

Should you find after the paint has dried, marks and stains from the mold are still showing through the top layer of paint, you can apply a second coat. Remember to wait until the initial coat is completely dry before doing this.

What are the best rooms to use the paint?

Rooms that require the most assistance in terms of mold remediation tend to be bathrooms, kitchens, attics, and basements, as these are the most likely to suffer from either high levels of humidity or a lack of airflow that can trap moisture within the air.

Fortunately, these rooms will all benefit from having Kilz anti-mold paint, as once the proper steps are taken to keep moisture levels down, such as installing passive ventilation, or extract fans, you can paint the walls with Kilz in order to assist in preventing any further fungi growth.

When to call a professional

Under certain circumstances, mold and mildew growth can become so thoroughly established that any attempt that you make to remediate yourself may be fruitless.

Ensuring remediation is completed correctly is vital as if the job is done poorly, painting over the surface of any affected walls will result in further growth later on, (as previously discussed).


Will Kilz paint kill mold on wood?

No, Kilz paint will not actually kill mold, as it does not contain the chemicals required to break down the fungi. It does however prevent further growth once it has been removed.

It is important to make sure the area is not only completely free of mold but also entirely dry before you attempt to paint it.

Does Kilz paint kill mold on ceilings?

No, Kilz paint will not kill mold on ceilings, as again it lacks the chemical makeup to do so. After proper ventilation methods are introduced to the bathroom and any previous mold has been removed and thoroughly cleaned, Kilz paint can be applied to the ceiling to help prevent new growth.

Is there a paint that kills mold?

There are many brands of primer and paints that claim to be able to kill mold, but this is rare. In most cases, these paints are better used as preventative measures, rather than as a method of killing pre-existing mold.


Kilz paint is a useful product that can be used to prevent mold growth and to be used as a preemptive measure in rooms where mold growth is likely. It will not actually kill mold but will create a barrier that makes it difficult for it to grow on.

Painting over pre-existing mold is not recommended, as it can continue to grow underneath, eventually breaking through to the surface.

In order to use the paint and primer effectively, ensure proper methods are used to clear any existing mold and preventative measures such as increased ventilation and humidity reduction are implemented before painting surfaces.

Chris Walker

Chris Walker has struggled for several years with mold after buying his own property. After finding the solutions to several issues around his home, he decided to create this site in order to answer as many questions about mold and mildew as possible to help others dealing with the same problems.

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