How can I effectively deodorize walls that have a stubborn funky smell from hidden grossness before installing new insulation and drywall?
Asked by Abigail Robinson 
1 month ago
Last Updated: August 12, 2024
Hey, could anyone give me some tips on how to get rid of the smell on these walls? The house we bought had some hidden grossness, so we ended up tearing out all the walls in the garage and living room. I’ve been running a fan, purifier, and dehumidifier for two weeks now, but the funky smell is still lingering. The exterior walls, especially the brown ones with brick on the other side, seem to be the worst. I really want to tackle this before we start putting up new insulation and drywall. Any advice would be greatly appreciated!
Maybe try using an ozone machine?
Hey, do you think it would help to use a sprayer and give them a light spray with Odoban? Or maybe rinse them off with a mix of baking soda and vinegar?
Instead of replacing the walls right away, have you considered using one or two ozone machines, sealing the home, and running them for 24 to 48 hours? This method can effectively eliminate organic smells, such as cigarettes, but may not work on all chemical odors. What kind of smell are you dealing with?
: Old musty walls in a 1973 house. We recently removed the original wood paneling.
: How long will it take for 100% of the ozone to disappear after turning off the ozone machines? If there’s a chance of any ozone lingering, we can’t use the machine due to people with respiratory sensitivities.
By, I would recommend getting a mold inspector to check out the house. Mold can be extremely hazardous.
We went through that process. They discovered an old dried-up area in the garage connected to the living room, and we had it remediated with the wood replaced. It seems like the only way to find out if there’s more is by tearing out the walls. The air test came back okay.
It’s really crucial to vent the ozone properly before anyone enters.
I usually just hire someone for this now, but the one time we tried it ourselves, it was a townhouse with four levels. We opened the front and back doors from the outside, waited around thirty minutes, then quickly opened the windows, and stepped out. Ozone has a very distinctive smell, so if you have a good nose, you can kind of sense when it’s safe.
The professional I hired uses a small self-inflatable air tank with a 10-minute supply when he needs to enter to collect the machine and power it off. Most of them use timers so they don’t have to go into the area while the machine is still running
You have the option to rent an ozone machine.
If you’re smelling mold, it might be coming from under the house. You might want to investigate. For smells behind walls, consider using a shellac or shellac-based primer. We used this method for fire damage and it worked in eliminating smoke odors
We had the crawl space cleaned and completely encapsulated because we found mold and no vapor barrier underneath. The previous owners neglected the maintenance of this house.
By, do you know who to contact for this type of job? I’m facing some problems and I suspect it’s related to this.
We hired a local company in Raleigh called Live Green. They specialize in crawl space encapsulation.
By, sounds good! I’ll look around nearby, thanks a bunch
You could try using a gentle bleach solution by spraying it. Mix 4 cups of water with 1/8 cup of bleach. Another option is to place open bags of charcoal in the area to help absorb the smell and moisture.
Kilz
So, the first step is to ensure that the source of the smell has been removed. Check for any current moisture issues. Once that’s taken care of and you’re left with just the odor, you can mix some bleach with water in a spray bottle (50/50 ratio) and spray it on the surfaces. Bleach is really good at killing the bacteria that causes odors. After letting it sit for a while, you can sprinkle baking soda over the area. Baking soda is a natural deodorizer that also helps to neutralize the bleach.
Make sure to avoid mixing vinegar with bleach because it can create toxic fumes. Vinegar is a great deodorizer!
Expressed gratitude and confirmed that the odor is coming from the 50-year-old wooden paneling walls. She plans to try using bleach to address the issue.
Mentioned that regardless of age, wooden paneling walls should not have a smell unless there is another underlying issue like mold, mildew, cat urine, or something else.
Found a lot of mice droppings and bones inside the walls. It looked like a scene from a pet cemetery. We cleaned everything up and applied 30% vinegar to the wooden beams at the base that had the unpleasant stuff, but the mildewy odor remains.
By: Oh no, that sounds terrible. If you’ve cleaned it thoroughly, it might be time to consider covering it with KILZ PRIMER.
Try using ozone or a ton of shellac primer
And not either lol
I mean if you’re not going to fix it right, at least give it a shot
I had some pressboard/pegboard that smelled mildewy and couldn’t get rid of the odor, so I ended up tossing it. But it wasn’t a whole wall. I’d suggest trying Concrobium instead of bleach, since bleach can make the spores spread before they’re killed. If that doesn’t work, painting with Kilz primer like D Douglas recommended might be a good solution.
We had to apply 2 coats of sealer to our concrete floor to get rid of the stitch, but it did the trick! Sherwin Williams suggested the sealer.
What in the world is going on with that electrical wiring? It looks like something out of a Fire Prevention magazine cover. I’ll be up all night thinking about it! 😂
I totally agree with – as long as the walls are open, it’s a good idea to check out the wiring.
Great! I’ll give him a call. Thank you! I really need an electrician because I have no clue what’s going on. I had no idea it was that bad. 🤦♀️
By is getting three different quotes and options! 😄
The ozone machine will first remove odors and then seal any contaminants with Kilz or latex paint.
Gave some really good advice
Drywall has a tendency to absorb odors, making it difficult to deodorize and encapsulate. Instead of spending a lot of time, money, and effort trying to patch up the issue with temporary solutions, it may be more efficient and cost-effective to remove the contaminated drywall and replace it with new material, especially considering the amount of space and easy access you have. All things considered, the rip out and installation process should be relatively simple.
Hey, the brown I have is against the outside brick. How should I remove that?
By hey, how close is it? Touching or is there a bit of a gap? If there’s any gap, you can probably remove the drywall there piece by piece and replace it with new drywall (or better yet, cement board for a damp area). You might be able to slide the sheets between the studs with some creative stretching and rearranging of electric cables. If there’s a large enough gap behind the brick to fit a drill, you can screw them onto the back side of the studs. But if the exposed studs face the main area of the basement, why put the drywall on the back side and still see the studs? You could instead put up a Vapor Barrier on the backside of the studs near the bricks and then finish the front side with cement board to hide the electric cables and give it a more polished look.
Hey, this is my living room. We recently removed the old 1970s wood paneling that had textured paint on it. The brown walls are connected to the exterior, while the lighter walls are in the guest bedroom.
By, I think they might be using that paneling as a moisture barrier to prevent dampness from the bricks. If they were to use drywall, it could start to mold, and even with cement board, the paper backing could get mildewy over time. In my opinion, a modern moisture barrier would be a much better option on the back side of the wall facing the brick. It would be quicker and easier to install compared to a solid board on the back of the studs. You could remove the current board, slide in sheets of poly or another moisture barrier plastic, attach it to the back of the studs, seal the seams, and then fill the cavities with insulation before putting up standard drywall on the front side.
I would start by contacting an Ozone company first and then apply Killz to everything.
I fully support the ozone suggestion. We used it in our newly purchased home that smelled strongly of cigarettes; it worked wonders. However, if there is mold present, the odor will return unless you deal with the underlying issue, naturally.
It’s not like the whole house smells bad. It’s just that wood smell when I give it a sniff. 😂 I know, I probably shouldn’t sniff it. My nose is just really sensitive, and I want to make sure we’ve done everything possible before putting the drywall back up. It’s mainly that brown cork board stuff that seems impossible to remove.
By so, when you say wood, are you talking about the studs? Or do you plan to keep the paneling?
Oh, I was actually referring to the paneling. You know, that cork board brown stuff and the drywall in the guest room.
By like I mentioned earlier, paneling doesn’t just smell bad because it’s old. If it was from heavy smoking or cat urine, the smell would be distinctive. If you can’t pinpoint it, it may be mold or a septic issue. I’d suggest identifying and addressing the problem, then replacing the paneling or drywall to truly get rid of the smell.
Give a chlorine dioxide treatment a try and seal the wood with paint, which is available in clear and white. During the chlorine treatment, make sure to leave the house for 24 hours while it airs out. And don’t forget to wear a face respirator to protect your lungs. Consider renting an air scrubber from a water mitigation company, which should be run for 3 days. I work for a water mitigation company and we also handle odors, that’s how we tackle such issues.
It’s actually safer to breathe in vinegar fumes than bleach. You can try spraying or diluting vinegar, wiping down walls and surfaces, and leaving some out to freshen the air for a few days. You can also use Kilz or primer to cover up any remaining smells. Another option is sprinkling baking soda on floors to absorb odors.
Odoban
Have you thought about reaching out to a professional cleaner to assess the situation and provide recommendations for cleanup?
We’ve had numerous visitors who haven’t been able to help. They claim they can’t determine the extent of mold without removing walls. Despite no moisture and testing by specialists.
By is it possible that they’re unable to monitor the air in the basement for mold?
Mentioned that they conducted a test and everything was okay. It wasn’t an ongoing test, but I bought more home tests to double-check.
When it comes to electrical work, make sure to take note of the metal plate on the stud face in the upper right corner of the photo. Install a nail directly over every spot where a wire passes through the stud to protect against accidentally driving a nail or screw through the wires while drywalling or hanging items like TVs and shelves. Avoid the risk of shorting, electric shock, and the laborious task of troubleshooting. Consider using ozone, bleach, or final coatings for added protection. Good luck!
I really appreciate your help!
Can you believe how messy the electrician was?
We usually spray it with shellac to cover up smoke in fire restoration projects.
You should check out ozone machines – they’re surprisingly affordable on Amazon.
I’m a fan of Killz paint as well.
When we moved into our new place, we removed the old carpet and used Killz spray on the subfloor that had an odor from cat urine. It did wonders. Just keep in mind, the spray might not be the best option if you have a large area to cover. Killz also offers a paint-on version, but I haven’t tried it before.
Try running an ozone machine in every room to freshen up the air. They are relatively affordable and easy to use. Just make sure to follow the instructions closely and keep people, pets, and plants out of the house while it’s in operation.
Killz
The wall in the first picture seems to be made of particle board, the kind that is similar to compressed cardboard. When it gets wet, it acts like a sponge. I’d definitely recommend removing it.
Ph Civitello mentioned that it’s located outside beneath the brick siding.
Hey ph Civitello, once we remove that, what should we put in its place?
Yep, that’s exactly right, !
By, if the particle board doesn’t feel wet, it could be an old wet stain. Leave it open for about a month with fans running if you can. Then put in insulation and cover the insulated wall with plastic sheeting before putting up the drywall.
Plastic? She painted the exterior brick?
They put plastic sheeting on the inside of the frame to enclose the insulation before putting up drywall. Why are we talking about exterior brick here? And where did you hear that the exterior brick was painted?
It definitely doesn’t work in my area.
If you have leaks in your outer walls, it’s important to address those before moving on to the next step. After fixing any leaks, consider using BIN primer (shellac) to seal in odors. Another good option is an oil-based primer.
When you apply shellac or any type of sealer to brick, the issue is that it can trap moisture. This can lead to mold growth if the brick is not allowed to dry properly. I’m not sure what the ideal solution is, but sealing it with a non-breathable coating is definitely not recommended.
Speaking of which, the previous owners decided to paint their brick, which also prevents it from breathing.
By Oh no, that’s unfortunate. I guess if the brick was really dry, it had no choice but to absorb into the wall. I’m curious if there’s a barrier between the brick and the plywood. Limewash is great for brick because it allows it to breathe. It also has anti-fungal properties, so maybe it could be beneficial to check into that.
Is there nothing we can do once the brick is painted? I might try removing this cork board to check if there’s a proper barrier between them. Thanks.
By I’m not entirely sure. I believe I’ve heard of people restoring brick, but I’m not certain. Perhaps you could consider repainting it every few years to maintain its seal on the exterior. The piece of plywood on top with the white patches seems suspicious to me, resembling the back of smelly drywall I once found in a location with a long-term leak. If it gives off a strong odor, like ammonia or something similar, it could indicate mold, although mold can have various scents. I recommend using a moisture meter with pins to test the walls multiple times, especially after rainfall, before proceeding. Best of luck!
I understand that and all the tests check out.
Maybe try an enzymatic cleaner?
Purchase several gallons of Odoban and carefully follow the instructions on the label…clean walls, floors, and ceilings with it. That should take care of the issue. My mother-in-law purchased a house that had cats kept inside and the odor was terrible. This method really worked wonders.
I completely agree. This has become a must-do for me. After Hurricane Harvey, I made sure to spray every stud once the walls were gutted. My house was flooded for a whole week, but the smell was completely eliminated.
Charcoal
Have you tried using a spray bottle of Clorox® Plus Tilex® Mold & Mildew Remover? It does a fantastic job of eliminating odors!
Another thing to consider, are you positive this wasn’t a meth house? You mentioned the house was in bad shape and smelled of smoke and cat urine. If you haven’t seen a lot of urine stains on the floor, and I mean a lot, you might want to have this house tested for meth. It wouldn’t be the first time a seller concealed this information to sell a house. If it is, or was a meth house, you can take legal action against them for not disclosing this information and they may have to cover the costs of removing the meth residue from the house, which can be expensive. If you can prove the former owner or realtor knew about it and didn’t inform you, they will be responsible for the expenses. Not confirming it’s meth, but a structure with a strong cat urine odor is one of the signs to watch out for. Also, if it could be meth, refrain from sniffing the walls and avoid entering the house until it has been professionally sanitized. Even the residue from that substance is hazardous and won’t simply disappear, it needs to be physically eliminated. Not confirming it’s meth, but it’s a good idea to check for peace of mind at the very least. Good luck.
It’s most likely mildew and it’s in what’s left of the wall board materials, like the drywall and the brown board. Any product you use will clean the surface, maybe into the wall board about 1/16 of an inch. But the mildew is still there, waiting for the right conditions to continue growing and stinking. The only way to be sure you’ve removed the source is to remove it all. And make sure to treat all the remaining studs with an anti-mold and mildew sealer. Many of these products also have anti-pest and insect compounds. But all the sprays, sealers, ozone treatments will only affect the surface. You have to remove the source.
I faced a similar issue in a back room. After removing the carpet and painting both the floor and walls, there’s still an unidentifiable odor lingering. I’m starting to lose hope.
Suggested giving it a spray with vodka
Give spraying some vodka a shot and let it dry out with a fan
We also had that issue. It wasn’t the walls, it was actually the floor and AC vents that were the problem. They installed a new hardwood floor over a subfloor contaminated with animal feces, and the vents were in a terrible state. The garage was no different – we had to scrub the floor with an animal urine cleaner and then apply epoxy. As for the other floors, we’ll need to remove and redo them. We hired a professional cleaner to take care of the AC vents.
Oh wow you’re totally talking about our place. No pet pee, just kind of stuffy and ancient. We ripped out the whole garage and we’re redoing all the insulation, walls, and ceiling. Then we’re gonna coat the floor with epoxy. I guess the floors in our living room are fine, but I’ll double-check now. Thanks
ByOh, and in our garage, the landscaping outside was too high, causing water to seep in through the wall. It was a mess! We had to add a drain and lower the landscaping. When we did our walk-through, the owners were still hanging around. But after closing, we discovered air fresheners crammed into every nook and cranny of the house. It was a strange find!
Oh wow, now I realize we ended up purchasing the same house! It’s like we did the exact same thing! The previous owners built a terrible DIY brick desk that sloped towards the garage and held water. We had to remove it, adjust the slope away from the house, and put in French drains all around the back. I swear, it feels like we had the same previous owners. 😂
By😂 Wow, that’s crazy!
Remove the particle board and drywall that appears to be covered in mildew. Check the framing, wiring, and foundation for any signs of mold and odor, then treat with TSP to eliminate it
When using an oil based product, I remember reading that adding drops of essential oils like peppermint, lavender, citrus, or eucalyptus to the primer or paint is recommended. However, if using a water based product, add natural extracts of your choice for a pleasant smell, such as 100% pure vanilla extract or lemon extract
Ozone! You can either use an industrial generator or UV-C lamps
Killz was the only thing that worked for us.
Check if there’s a portable ozonator available for use
Ozone generator
These are definitely worth the investment
I saw some new stuff being promoted, I wonder if it actually works?
Hire an ozone machine
How does it smell? Like mold? Breathing in mold is harmful and can lead to cancer if not handled carefully. Spraying vinegar will eliminate it (spray, don’t touch, then leave for 10 minutes), but it’s crucial to remove it visibly even a foot beyond the sprayed area.
We found dry mold in , so we had it removed along with the wood, and then we used 30% vinegar all around to be safe.
As a cost-effective and simple way to eliminate odors and more, I wouldn’t recommend staying there for a few days after using this method (until the smell is gone). Head to Lowe’s or another store and purchase pool shock. Mix it 50/50 with water in a sprayer and apply it to wooden floors or walls. It cleans them effectively, eliminates odors, and eradicates mold. Remember to cover anything you don’t want to stain. You can wear a respirator if you choose, or just apply it and leave…haha. Let it sit, scrub it if desired, then return later to check the scent. The chlorine odor dissipates within a couple of days, along with any other smells. If you’ve ever had old outdoor wood, you’ll be surprised how quickly this method cleans it up. It removes weathered stains in seconds without requiring scrubbing or excessive effort. Now, bring on the negative comments. Haha. Feel free to disagree with me, but sometimes I notice people here tend to overthink and complicate things unnecessarily.