Does Kilz Kill Mold? How to Use Kilz for Mold & Mildew

Unfortunately, despite its name, Kilz paint does not kill mold.

So what does Kilz actually do?

Kilz Paint has an antimicrobial chemical in it, that is fantastic for preventing mold or mildew from growing on its surface.

This makes it ideal for use in more humid areas of the house or outdoors, but it works best as a preventative measure only.

In terms of handling mold and mildew, Kilz paints are a proactive step to take, not a reactive one.

Using it reactively on mold and mildew will cover the problem up visually for a few months at best before the paint begins to crack, bubble, and flake from new and continued mold and mildew growth.

Do not try to spray Kilz on mold as if it were an anti-mold treatment, as it will not kill or even contain the mold or mildew.

It will simply cover it up for a period of time, while leaving the people inside your structure at risk from harmful spores.

Kilz does not destroy or neutralize one of the most dangerous types of mold: black mold. Many types of mold and mildew spores are toxic and can cause rashes, respiratory distress, headaches, or worse, especially if there are any immunocompromised people in your building.

What Kilz actually does “kill” are stains and stink.

Its water-based latex paints and oil-based paints are excellent options when trying to cover stains on your wall that usually “bleed” through other paints.

An important part of the equation, however, is that you use the right primer before you paint.

Does Kilz Primer Kill Mold?

Unfortunately, despite its name, still no. Kilz primer does not kill mold either.

Kilz Primer has an EPA approved antimicrobial chemical in it, same as the paint, that is fantastic for preventing mold or mildew from growing on its surface.

This makes it ideal for use in more humid areas of the house or outdoors, but again, only as a preventative measure.

What Kilz actually “kills” are stains and stink.

Kilz water-based latex primer and oil-based primer are excellent options when trying to cover difficult stains on your wall that usually “bleed” through other primers.

Priming is a critical step to take before painting any surface.

Can You Simply Paint Over Mold Or Mildew With Kilz?

Technically you can, but you will likely be unhappy with the results unless you take the correct steps before painting, which we will discuss in more detail later.

Kilz primers and paints may be phenomenal at locking stains behind their coats, including neutralized mold and mildew stains, but painting over active mold and mildew can actually make your problems worse.

Now the mold and mildew have a nice, dark, unventilated place to grow and flourish.

With enough time, the organisms are likely to bubble and crack the paint as they come back with a vengeance.

All the while, the spores from the mold and mildew will be spreading through your house, potentially making you and your family ill and causing other spaces to develop mold and mildew.

The only thing you are doing when you paint over untreated mold or mildew is giving it a good home while leaving your own home worse off.

However, if the mold or mildew stain is neutralized or very small and nontoxic, it is okay to paint over it. If you are unsure, contact a professional to be safe.

Best Usage Scenarios For Kilz Application

There are plenty of scenarios where Kilz application is a good idea, but these are the three most important:

Locking Stains

Kilz is phenomenal at covering up stains.

They can be neutralized mold and mildew stains, but they can also be stains from smoke, rust, food, blood, marker, crayon, lipstick, water damage, or even urine.

Kilz primers and paints are well known for their ability to cover up stains, and they have been good at it for over four decades of business.

Sealing Odors

Part of locking the stains away is locking the stink away too.

If you have strong odors in your home from cigarette smokers, poorly trained animals, or mold and mildew spots, you want to do two things: deep clean or replace your carpets and upholstery, including fabric furniture, and use Kilz primers and paints to seal the stink away.

Everyone deserves a fresh, clean-smelling home, and you are no exception.

Preventing Mold and Mildew

Perhaps the most important factor setting Kilz apart from most other paint brands is its antimicrobial properties that inhibit the growth of mold and mildew on its surface.

It is not a 100% guarantee that no mold will grow, but it is an important preventative step for any homeowner.

Get the jump on mold and mildew by using Kilz in your pool house, kitchen, bathrooms, and laundry room.

It can also be used for the interiors of outdoor sheds to help prevent growth in areas that are not seen as often as others.

How To Paint With Kilz For Best Results Against Mold Growth

The following steps are crucial when dealing with mold or mildew.

We strongly suggest you wear a good dust mask and eye protection any time you are near or working with mold or mildew to protect yourself from potentially harmful spores.

Open a window and get a fan blowing to create a cross-breeze and ventilate the room; this will also expedite the drying process for some of the steps while keeping you safer from spores and chemical fumes.

Just be sure to complete these steps in numerical order to prevent wasting your time and money!

Step 1: Nip It In The Bud

The first step is always the same: find the cause of the issue and stop it before treating the issue.

Mold and mildew do not happen in a vacuum. They require regular moisture, poor ventilation, and often dark environs.

You may have water damage inside your wall from a leak you are not aware of. You may be dealing with exterior humidity from the weather, which cannot really be helped, or interior humidity in a kitchen, laundry room, or bathroom, which can be helped.

Find the source of moisture if it is inside your wall and stop it, or find a way to keep the space permanently well-ventilated to help prevent future growth.

Step 2: Murder the Mold and Mildew

You will need gloves and a good dust mask to keep yourself safe during this step. As a warning, never sand mold or mildew.

All you will do is kick up scores of potentially toxic spores, making you and others sick while spreading the mold and mildew to new locations for growth.

Instead, you will need a special cleaner to treat the area. Some home remedies recommend bleach or undiluted white vinegar, and while these options are cheap and often readily available, they are not effective against all types of mold and mildew.

To be truly sure, use borax or a powerful mold and mildew cleanser from your local hardware store.

Carefully use a sponge or rag to clean and scrub as much of the mold and mildew off the wall as you can.

Don’t worry about damaging the paint a little, as you will eventually be painting over it anyway.

Go over the visible mold and mildew stains twice to be sure.

Once the cleaning is done and the spores have been neutralized, let the whole thing dry out completely.

Step 3: Optimal Prime

Get your Kilz Primer and start rolling, painting, or spraying it on.

Use Kilz water-based latex primer for mold or mildew on drywall for best results, and likewise use Kilz oil-based primer for mold or mildew on wood for best results.

You want at least one coat, but two coats are usually best. Allow primer to dry completely between coats.

The primer will seal the neutralized stains behind it, preventing bleed-through, while creating an ideal surface for paint to grip.

It will also help prevent future mold or mildew growth, along with good ventilation. Allow the primer to dry completely.

Step 4: Paint and Pleasure

Get your Kilz Paint in your preferred color and start rolling, painting, or spraying it on.

At least two coats of Kilz paint are recommended for a smooth, even looking wall. Allow paint to dry completely between coats.

The paint will help seal the neutralized stains behind it, helping the primer in preventing bleed-through, and, more importantly, helping prevent future mold and mildew from even developing.

Just be sure to keep the area well-ventilated. Allow the paint to dry completely, and pat yourself on the back for a job well done.

When To Call A Professional

When dealing with mold and mildew, you should contact a professional if:

  • The mold covers an area larger than 10 square feet
  • You are unable to clean and contain the outbreak yourself
  • You are unable to identify whether or not the mold or mildew is toxic
  • You have identified the mold or mildew as toxic
  • You discover the mold goes all the way through your drywall, into your vents, or is otherwise pervasive
  • You are immunocompromised or allergic to common molds and mildews

When in doubt, play it safe. If you are unsure of the risk to you or your family, do not wait. Contact a professional mold remediation expert for help.

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