Does Painting Over Mold or Mildew With Kilz Paint Kill Them?

If you are wondering if painting over mold and mildew with Kilz mold and mildew resistant primer will kill the mold and midlew, the short answer is no. Kilz was designed to prevent mold and mildew not to kill them once they have already grown. This article will discuss what Kilz is, and why it’s not an effective solution for killing mold and mildew that has already grown.

What is Kilz, and What Does Kilz Do for Mold?

Kilz is a company that makes paint primers designed to prevent black mold and other types of mold, mildew, stains or odor in your property. Kilz makes an aerosol spray paint primer for mold and a regular paint primer for mold. The spray paint primer is designed for small and hard to reach places while the regular paint primer is good for larger surfaces that are easy to reach. The Kilz mold and mildew products are water based primer-sealer-stainblockers that are made for building surfaces that are at high risk for mold and mildew growth due to high levels of nearby humidity or moisture. They provide good adhesion on both interior and exterior surfaces and offer a good paint anchor like primers are typically supposed to do.

Kilz Mold and Mildew Resistant Primer

Will Kilz Cover Mold?

Kilz should not be used to “cover” mold on drywall or on some any other surface in your property. Even if you paint over mold with Kilz, it will not kill the mold so the mold can still cause you health problems and damage your property.

Will Kilz Kill Mildew?

If you are wondering if Kilz will kill mildew, the short answer is no. Mildew needs to first be cleaned using vinegar and hydrogen-peroxide before it’s painted over with Kilz. To explain why that is, it’s important to understand how mildew differs from mold. Mold can cause serious health and property damage while mildew is much less harmful. Also, mold is much more difficult to get rid of because it expands behind walls while mildew just grows on the surface.

Why Kilz Doesn’t Work for Mold

While Kilz is good for preventing future mold growth, it won’t work against mold that is already growing for the reasons below.

Reason 1: The Mold Needs to Be Addressed

The mold contaminated building materials need to be removed and replaced before Kilz can be applied. If you tried to paint over mold with Kilz without addressing the mold first, it would only cover-up the mold stain.

Reason 2: The Moisture Source Needs to Be Addressed

Even if you address the mold properly, the moisture source that is feeding the mold needs to be taken care of in order to prevent the mold from returning. So if you want to actually get rid of the mold for good, you will need a professional to identify and fix the issue that is causing the moisture in your property. In addition, you will need to dry or get rid of any water damaged building materials because they are prime breeding grounds for mold. The good news is that our nationwide network of mold remediation contractors, can do all of this for you.

Call us now for a free mold inspection remediation quote!

What is Kilz Paint Used For?

Even though Kilz is not an effective solution for killing mold that is already there, it could be a good idea to apply it after you get the mold properly remediated to prevent it from growing back. The manufactures claim that it creates a mold and mildew-resistant film that shields the areas that it’s applied to from mold and mildew growth.


If you have mold growing in your property you need to first get it professionally remediated, and get the moisture source and water damaged building materials taken care of before using a mold prevention product like Kilz. The good news is that we can take care of the first part for you, and apply Kilz primer upon request. We have trained technicians on-call 24/7 ready to help you with any issues related to mold.

Call us now for a free mold inspection and remediation estimate!