We know that everyone wants a one-step easy solution and Zinsser mold killing primer and mold killing paints sound great, but…is it really that easy?
Will mold killing primer and mold resistant paint be enough to protect me?
Mold inhibiting paint will not kill mold! The general name is ‘mildew’, and it will grow right through ordinary house paint: you must remove all you can, then SEAL it with a mold killing primer. It’s not the nightmare you were expecting, and we simplified it all here.
List of what you need before you paint over mold
- Safety first: 3M's full face respirator mold remediation kit which you see just below…or use the painter’s workhorse respirator discussed in this post.
- Mold killing primer by Zinsser
- Mold resistant paint: Rust-Oleum.
- A non-toxic prevention spray called BioBarrier
- Bleach (this bleach concentrate is great)
- Quality rubber gloves (I highly recommend these)
- Rags (you can even find rags online) (some dyed rags bleed when you wipe, staining the wall, etc.)
After painting, inhibit growth another way in damp areas with a non-toxic spray that takes 6 months to wash off. This plus the special-mold proof-paint will make your life easier (and safer).
Ceiling mold? Bathroom mold, garage or basement mold? You will use the same routine to kill and cover it. Ceiling mold may be the hardest on that list because it is over your head: you will need special protection for your eyes and face from dripping bleach solution and your mold killing primer and your mold resistant paint.
6 easy steps to paint over mold
- Don’t breathe the spores: put on your respirator (our article on respirator mask simplifies the weird world of respirators). Scrape off any loose mold and recover it for disposal
- Create a semi-strong bleach solution, depending on the problem. Typically 1:3 (bleach: water)…I hate to be pushy, but you also must wear a respirator (indoors) as the chlorine gas is deadly! Ventilate well and protect the floor
- Put rubber gloves on (don’t go cheap on this one: re-use quality gloves)
- Wipe with any rag until no more black/green comes off
- Rinse the surface with clean, wet rags. Leave rags outside away from people/animals
- Let dry – your first coat should be a mold killing or resistant primer, then two coats of mold resistant paint
If you have a very large area to treat, you can use a sprayer (please wear protection!) You would not want to use your garden sprayer here as the plastic will probably not handle the bleach solution well. Conversely, a sprayer that works with bleach will probably also be fine with garden solutions. Bleaching inside can be very deadly: choose from the respirators above.
At the end of the post is a video of me breaking the rules killing some mold in our garage: I should have had gloves on, but could not wear a respirator and talk to you!
Careful with manufacturers’ promises: don’t trust the ads that make that claim they have a paint to cover mold or kill mold
When you hear about anti-mold paint, it is not a mold-prevention paint and certainly not a mold killing primer.
Mold inhibiting paint can only resist, not prevent mold, You will make a fortune if you can invent a one-step mold killing paint! There is what is called a mold killing primer: Mold killing primer by Zinsser makes good claims, but let’s be reasonable. It depends on the situation.
Important points for the paint to cover mold
If you have powdery mold sitting on your surfaces, do you really want to mix that into your walls for the future, or leave it for someone else to live with? Just follow the steps above to paint over the mold and you’ll have peace of mind.
Also, the stain mold leaves behind must be totally sealed or it will bleed through your latex paint. Zinsser Mold Killing Primer just says, “aides in covering residual microbiological and fungal stains”. Not good enough, sirs.
For serious stains, get a quart of shellac-based BIN primer or by the gallon. We use it as overkill or as we say “Over Kilz”. Rubbing alcohol is the solvent. We have an entire post about painting over stains. It’s very messy so wear gloves and don’t inhale, Bill.
Again, the respirators at the top of this post will protect you.
We follow our primer with the best mold resistant paint: the Benjamin Moore Aura mentioned below.
Flat, Satin or Semi-Gloss?
Through my 30+ years as a painter, I have seen the trend change from “always semi-gloss in bathrooms and kitchens” to “anything goes”. The chemistry of paint today allows you to do whatever you want, but still flat and matte paints finishes are naturally going to hold water longer than shiny paints: but they look better! So most people compromise with satin and eggshell. If you keep a bathroom or high moisture area clean, you will not have mold and mildew growth. It’s actually the easy way.
You will find some gorgeous bathroom paint colors on the internet. Keep in mind that smaller rooms benefit from lighter colors and more light inhibits mold growth.
What we do
Mold paints do not kill mold! They inhibit growth. So after you do the prep described below, choose THE+BEST paint. We recommend using the best paints, as we have written, it is a money-saver and you don’t have to paint as often. It’s really a no-brainer.
For bathrooms and other high moisture areas where mold loves to grow, we recommend Rust-Oleum. The technology behind it is a formula to lock out moisture and prevent or deter mildew/mold growth.
Fixing a hole where the rain gets in? Flex Seal Liquid Rubber makes sealing leaks easy
Before you replace a cracked sink or floor etc, it’s worth a few bucks to try to seal it and a product I discovered at Home Depot Flex Seal paint. You’ll find Flex Seal at Lowes as well as online. I fixed my cracked garage sink with a liquid sealer and it kept me from replacing it!
Health Dangers of Mold in Your Home
Some people are more sensitive, but mold affects everyone. Symptoms of mold exposure can include:
- Nasal and sinus congestion, runny nose
- Respiratory problems, such as wheezing and difficulty breathing, chest tightness
- A cough
- Throat irritation
- Sneezing / Sneezing fits
Thank you, Wikipedia.
One Ingenious Pro Tip: Every time you dip a brush into a can of this nasty primer, you are sacrificing that brush. You don’t mind? Do you have a dollarstore brush or an oldie? Sure, but how many will you kill each time you spot some mold or stain that you know you must prime?
What do pros do? We leave a crappy brush in the can for life. If the can is small, we cut or break the handle. After weeks in the can, is it all mushed up and bent? Yes So? It’s wet and ready! Unless we have a large area to seal, we don’t care. The brush strokes from a primer will usually flatten out when dry and if not, will sand fairly well. Faster…Better…ALMOST FREE!
Certain mycotoxins can be harmful or lethal to humans and animals when exposure is high enough.
An easy way to prevent the growth of mold in dark and/or damp areas in your home is the use of a UVC lamp. Research shows that UVC lamps kill mold, the airborne allergens, bacteria, viruses and protozoa in your home or office. Ultraviolet light breaks up the DNA of mold and mildews which results in the sterilization of the mold.
We tried a hospital style UV wand but found that it gobbled up batteries, then even with new batteries did not work anymore. Now we are testing a compact germicidal fluorescent bulb in our mold areas. More later on this!
Prevent mold growth:
- Increase ventilation and sunlight or UV bulbs if possible
- Clean surfaces with strong cleanser or very weak bleach solutions
- Check nearby plants for mold
- Bright light inhibits mold growth
- Don’t leave very wet towels/puddles around
- Use mold-killing primers and mold resistant paint
- Just be glad it’s not the old days when they put mercury in mold paints as a fungicide.
- Thanks, science
Black, gray, green, brown, it’s moldy and it stinks and it’s a health hazard. Don’t just paint over it even with a mold killing primer and a mold resistant paint: you have to clean it safely first!
We used this mold test and found penicillin and one other: not deadly, but just sayin’.
PS read about mold and mildew on Wikipedia, the Overlord of us all.
Let us know in the comments if we left anything out. Thanks.
How to Paint over mold video