Customer Reviews for Zinsser 1 qt. Mold Killing Interior/Exterior Primer (4-Pack)

[This review was collected as part of a promotion.] This mold killing primer is excellent. We are remodeling a home that hadn't been lived in for 8 years. Naturally there were leaks and mold had formed. This primer keeps mold from bleeding through before drywall finishing or painting. Of course, you must fix the leak first, but after that, one coat generally does the trick.

[This review was collected as part of a promotion.] I used this base to cover the post of the mailbox that had turned green. I plan to use it outside the house to cover a bit that has turned green. I recommend it. It is very easy to apply just the water to stir the paint well. The smell is not strong, it is a normal smell of paint. It is very easy to use and to open, it comes well closed. and you can open it very easily.

[This review was collected as part of a promotion.] I had a lot of mold/phosphorus on the basement wall and after I prepared the wall, I applied a coat of this mold killing primer and it worked fabulously. It rolls on just like a coat of paint, and I think a second coat would work even better, being that the wall really was in bad shape to begin with. In our area, the temperatures are quite cold right now, so over the winter and when spring arrives will be the real test for longevity. However, right now it is holding up well and looks great. I am happy with the result and quite impressed with how well it looks right now. Truly a great product to allow you to cover right over mold and make everything look brand new again.. AAA+++

Amazing product, simply amazing!!!! I highly recommend it!!!

This paint was a miracle save for our bathroom ceiling

As a primer it works well but as a means to prevent mold from growing, it fails. After a month, the mold returned due to high humidity in the garage.

I bought this product 5 months ago. I went to use it the second time and it had mold growing all on the surface. Doesn’t seem to work as a mold killer.

I cleaned the red mold off my bathroom walls with soap and water then just painted the entire restroom. Technically I didn't need to clean the walls to apply the Zinsser mold killing primer but I did anyways just to be on the safe side.

Did a great job covering the mold. Time will tell how well it holds up!

Does not penetrate into drywall, covers surface only see pic.

This stuff works great! I had piece of drywall with surface mold and 2 coats of primer it looks like new again. Great product

I am really impressed with Rustoleum Zinsser's Mold Killing Primer, I was thinking could this really be true, reviews seem to go both ways but I was willing to give it a try. Had been very hot and humid when it came in and then raining, so had to wait till had a nice day to apply and wall was dry, finally got my wish . Have wall between man door and overhead garage door that leaks when hit with heavy rain and drywall near wall gets wet and before I can get gutters installed to stop leaks, need to clear up mold or redo the drywall. But thanks to this great primer I can go ahead and finish paint, will wait a couple more weeks to make sure all is dry but seems to have cured the mold and I can get gutters installed now that is not 105 deg in the sun. Can only say thanks to Zinner

Last year after hurricane Irma the big concern was mold, as salt water storm surge had flooded the area. I would have liked to have used this product then, but now even though there is not any showing, I am going to apply the Zinsser mold killing primer to the affected areas and then apply a topcoat as a prevention. First I applied it using a 3" brush and even though it worked it is thin and I had to pay close attention to it dripping or running. The next day I applied it using a 6" roller on several different extensions. I used a 1/2" nap 6" cover and that worked best because it holds more paint than a 3/8 cover and it could be pressed into the corners and cover the areas without having to follow up with a brush and best of all fewer drips. I liked that it can be used as an exterior primer, no smell or fumes and easy water clean up.

I used this on my wooden garage door that had all kinds of black mildew stains on it. I washed what I could off the door, but it was still very dirty looking. I put 2 coats on, though I think I could've just used one, but because I didn't want to paint the door again any time soon I didn't want to chance it. It covered very well, none of the stains came through. I liked that it was latex primer instead of oil based. I was outside, though I didn't think it was too smelly to use indoors. I would definitely use this again.

Considering the problems this product solved for me, the price (thru HD) was excellent. Now to the lessons learned. 1) When you clean your house, you may have invisible mold spores or roots still in the wood/substrate. Clearly I did as I bleached, SCRUBBED, and rinsed the previously sealed cedar siding on my front porch - which is on the NW side/front of the house. I had previously used an alkyd primer and solid-stain (rubbol) on this same cedar siding. Then I minimally touched up using Ben Moore's alkyd primer, following up with 2 coats of Sikkens rubbol solid-hide stain (which I love). This was early June, 2016. About 10 day later, I saw mold growing. When I cleaned the surface, I realized the mold was UNDERNEATH the recently applied rubbol finish. (Looks and feels like silky paint.) It was actually growing underneath and creating darker areas everywhere the siding was below the top-most plane of the surface! 2.) Freaking out, I started researching online and spoke to my paint supplier. This stuff got great reviews from my trusted supplier so I ordered it from HD. Then I brought the cans to my supplier for tinting (HD's price beat my contractor's price but comes in white.) 3.) Early July 2016, I left the original porch covered area alone and continued cleaning the other sides of the house, adding the additional step of the Mold Killing Primer (MKP) before touch-up caulking and reapplying the rubbol finish. In the meantime, the original surface was growing mold again in less than a week. Then I finished the NW side which is not covered by the porch and two separate NE sides of the house. Then I bleached the front porch again - still seeing the darker/grayer areas in the deeper planes of the siding. (Note that the trim, the floor, and the ceiling did not have this same problem as they did not have the texture that the cedar siding did.) Fine, so now I've bleached the area under the 38'w x 8'd x 10'h NW-facing front porch 3X. Mold is still visible beneath the recently applied Sikkens Rubbol Finish. 4.) Then I focus on the rear of the house where I had previously only applied the alkyd primer a few years ago. This time I bleached and pressure-washed the siding, then followed up with the MKP. All seemed great. Then the rains came. I couldn't re-coat the primer due to the monsoon and 8" of rain in 3 days in Central VA. In only 6 days, mold was regrowing on this SE, under-the-rear-porch area of the house. Crestfallen at the reappearance of mold, I realized I was able to wipe off the new mold. So, it was only on the surface of the recently applied MKP. Fine, so got out the bleach sprayer, reapplied solution, and then began to rinse with just a hose, not pressure wash. SHOCK - the primer started to PEEL OFF! Again, calls to my supplier. Turns out, I hadn't waited long enough for the wood to dry out from all the moisture - in the wood, in the primer, in the environment. I left everything alone and persisted in the areas that hadn't gotten wet from the rain. And I waited about 5 more days to re-coat the siding with the MKP and then the Sikkens finish. (I also added a mold inhibitor to each of the gallons of the Sikkens Rubbol finish, especially since it is a alkyd/latex blend and mold LOVES oil-based materials.) Several days after I completed all of that, I tested to see if any of the product was peeling or even able to be scraped off ----NOPE, all adhesion is great! 5.) Now, early October, 2016 - no mold has regrown on any boards that I first covered with the MKP before reapplying the final finish. But it's growing just fine on the front porch siding. So, I moved back to the front porch to finally addressed the subsurface mold. Again, very obvious black mold spores covering about 25% of the surfaces of the siding growing thru from I guess roots left behind from June 2016. So it was 10/11/16, the fourth time I've applied cleaning solution to the siding and the third time I've pressure-washed. The next day - I used my recently purchased moisture meter and got a reading of 2%, knowing that the boards were dry from the pressure-wash. (They would be because they were already plenty sealed, just with mold encapsulated.) 6.) 10/12/16 I liberally applied the MKP to all siding under the porch. It visually concealed the mold more when it was wet but I could sort of see the darker greyish color underneath as it dried. I let it dry overnight. Checking this morning. I can't see mold underneath. It's 10 a.m. and 58 degrees outside. The moisture meter is reading 21% on the recently primed siding. And the can states that the material can be re-coated within 30 minutes and re-coated with any finish. Once the humidity gets a bit higher outside, I will apply the first coat of the rubbol finish. TO SUMMARIZE LESSONS LEARNED * Always pressure wash siding after cleaning to ensure that mold spores that are killed or invisible due to bleach are detached from the substrate. Scrubbing textured surfaces does not ensure removal of all unwanted material. * When reapplying paint, stains, or sealants, seriously consider reapplying some sort of treatment that clears away mold roots and/or mold spores. These items are available in primers, spray treatments, or additives to paints. (Had I done this on the first area refinished, I would have saved the time & material cost of three more cleanings and two coats of finish on the 38' x 10' front porch wall.) * Invest the approximate $50 in a moisture meter to let you know when boards are dry enough to apply solutions according to manufacturer instructions. * Allow the stated amount of time for sealants to dry before adding additional treatments. a.) Had I waited more than one day for the rear porch cedar siding to dry out from the initial clean and pressure wash, the MKP would have had enough time to dry and may not have supported mold on it's surface to begin with. b.) Had I not applied more solution to remove the surface mold on that siding on the rear, the primer wouldn't have peeled off where it did. Where I left it alone to dry, it adhered and I was successfully able to reapply more MKP and 2 coats of finish. All is well today, 2 weeks later on the rear porch. This week, with low humidity, I will complete the front siding, adding the Sikkens Rubbol and reinstalling my beautiful front porch furniture. Then I can sit back with a cup of coffee, and RELAX into Fall, 2016.

Number one this product is overpriced. There is no way it is worth more than $20 a gallon. True, it did block the water stain and signs of mold, however as you can see it was not absorbed into the drywall. (Note: the primer had been on the ceiling for at least 2 weeks before I started painting.) I used regular ceiling paint with a little bit of added texture to cover any imperfections in the ceiling. Admittedly, it was a bit thicker and heavier than regular paint. As I was about to finish, I noticed a small air pocket where the paint and primer had come loose from the ceiling, as I went up on the ladder that small area got bigger and bigger until finally about 20 square feet had come loose from the ceiling, about the exact area that I used the Zinnser mold killing primer as opposed to my regular Behr primer. Horribly flawed product, and now I have to start over. What more can I say about it?

I have two spare rooms that I plan to renovate but I’m not ready to start yet so I’m trying this product out on a scrap piece of wood for now. When I received this there was some paint around the rim by the lid which I thought was a little strange coming straight from the factory. This is quite thick so it puts on a good layer with just one coat, see pictures. It also does not need to have a topcoat on it. It can be recoated in an hour which is pretty good. Because this kills mold and mildew it has pesticide safety warnings on it as well as the normal paint safety warnings so you should take notice and be careful with it. I don’t know how effective it is against mold because I would have to judge that over time and see if any mold comes back. I’m assuming it does the job it says it does. If I see any mold on it later I’ll re-review it.

We were going to put new counter tops and sinks in both bathrooms. The master bath went smoothly. When it came to the second bathroom. we found a mold when we removed the old counter top from the cabinet. I than removed the cabinet and found mold in the sheet-rock and back and bottom of the cabinet. I removed the cabinet to be rebuilt (since HD guessed $500.00 for a custom built one). After everything was taken out I painted all the studs, drywall back ( other wall) and some of the sub-floor. I hope this stuff works, the new dry-wall I cover the studs will not let me see what is happening inside the wall. The new dry-wall will also be painted (both sides) with this primer. I hope I never see mold in that area again.

Pulling down the wallpaper in the master bathroom revealed a nightmare mess. The walls were covered with mold/mildew. I read the reviews on this product and decided it was worth a chance. It's a small bathroom so 1 gallon was more than enough to put on two coats and still have some left over. It's been just a month but, so far, there's been no tell-tale return. Prior to this purchase and application, I'd have to scrub my ceiling down with bleach at least a month. Now, it's absolutely sparkling!

I used this product recently for two different applications -- both ceilings. In one instance, my bedroom ceiling suffered damage due to a roof leak (see picture), and the sheetrock and insulation needed to be replaced (see picture). I painted the repair with Zinsser Mold preventive paint as a precaution since I was uncertain that all of the damaged and wet building materials above the ceiling had been fully removed. In this case, there were no stains to cover. The paint appeared a little thin for a primer-style product, but it provided reasonable coverage for a "primer" coat. If I didn't intend to apply a finish coat, I would have had to apply two coats of Zinsser for better coverage. In the other instance, I had to cover an area of minor water staining -- again caused by a smaller roof leak in a different area of my house. I had previously covered this same area with a competitive product K***, which when the leak continued, did not hold the stain back. The roof has been repaired in this area too -- now only time will tell whether the Zinsser product will do a better job of covering the old stain than the competitors product did. The product washed up quickly and easily. Nothing I experienced would cause me not to recommend the product.

This is a white water-based primer that has some antibacterial elements. The intent is for a coating to kill and prevent recurrence of mold, mildew, and bacteria. It goes on fairly thick and covers well any mildew stains that are not intense. The real question I cannot answer is the long term result. After one week of applying a coat to some mildew-infected siding, the paint is still clear of the mildew that was underneath and none has reappeared on top. It will be interesting to see how long this lasts. Ordinary chlorine bleach had been used in years past to eliminate the mildew, but it always came back fairly quickly. The key chemical in this product is 3-Iodo-2-propynylbutylcarbamate (IPBC) which is commonly used in some skin cosmetics as a fungicide/antimicrobial. The EPA allows as much as 0.1% in the cosmetics, but they commonly have only about 0.012% concentration. This product has a concentration of only 0.0063%, or a little over half of what is used on your skin. I do not understand why, at least, the 0.1% concentration couldn't be used. So, I suspect this is not as effective as advertised. It would only deliver half as much fungicide/antimicrobial as a coating of Maybelline coverup. Call me skeptical, but for now I'm on the fence about this product, with 3 stars and no recommendation either way.

I had issues with my garage wall that kept getting stained and grew mildew due to the humidity during rainy season and this stuff really covered all that. After a week of applying this on the wall I can’t see any sign of mildew coming back. The product arrived well packaged. Easy to apply, it goes on very smoothly on the wall with a regular roller.

Great product. Easy to use.

Covered well. No mold bleed through on block wall,

covers great and very low order, did the job under the sink