What could have caused the mould in my son’s bedroom corner and what is the best way to remove it properly?
Asked by Milagros Muñoz 
7 months ago
Last Updated: May 20, 2024
Hey, so I discovered a mold spot in my son’s room, but it’s only in one corner. I checked the whole upstairs and there’s no other mold anywhere. I’m going to clean and treat it today, but it’s making me wonder how it got there in the first place.
Any thoughts on what might have caused it? And do you have any tips on the best way to get rid of it properly?
I’m thinking of cleaning it, treating it with concombrium, cleaning again, and then painting over it. Is there anything else I should do? How can I figure out where this mold is coming from?
The area behind this corner seems to be quite moldy and requires attention. Let’s remove that part and take a closer look. You seem to have excess moisture coming from above – could it be a roof leak, bathroom leak, or window leak?
Looks like it’s coming from the right side. Moving along the frame towards the corner.
I think the moisture issue might be related to the abundance of plants in that area. As a fellow plant lover, I know that having too many plants in one spot can lead to excessive moisture. You might want to consider spacing them out or using a fan to reduce the dampness caused by wet soil. The water evaporating could be pooling in the corner due to lack of proper ventilation.
I never realized that and have been including plants… good to keep in mind, thanks!
Hey, did you know that the plants aren’t providing enough moisture for that?
I understand it’s moisture from above the ceiling. I also noticed the other area and have had a similar experience with a leaky roof. That’s not the reason I’m grateful to her… it was about the importance of good air flow, except for those who thrive in high humidity. Water vapor is a major contributor to mold, as mentioned.
There seems to be moisture somewhere. Maybe take a look at the gutter and soffits/roof area. We definitely need to locate it. Using cleaner will just hide the issue.
I think there needs to be better insulation, since it seems like the condensation is occurring inside.
Are there cracks in the outer wall?
If there’s an exterior wall in that corner, it’s possible that the cold outdoor air is meeting the warm indoor air, resulting in condensation and eventually mold growth. I experienced a similar problem when I lived in an apartment. Having a downspout connected to your house right outside that corner could be exacerbating the issue.
This is an exterior wall, and there’s a downspout in that corner. My husband checked and there was no damage on the roof or any visible damage outside.
Could it be that downspout gets blocked up when it rains? Maybe it’s clogged?
There must be a source of water coming in. Mold thrives on moisture. Address the root cause before attempting to clean and paint. Otherwise, the issue will just keep recurring.
The additional moisture from the downspout doesn’t help, especially in cold weather. Also, check where it’s secured to the house outside using screws. Over time, those holes can deteriorate from temperature changes, letting in both air and moisture.
Oh, I was just about to mention that! It’s a pretty common issue with outside corners. Just make sure the insulation is properly placed in the corner and hasn’t shifted over time.
Are you able to access the attic?
You’ve got more going on behind that drywall. It’s visible to the right in your photo. To fully address the issue, you’ll need to remove enough to completely cut out the affected area, as it goes beyond just the surface of the drywall. Consider using RMR 141 (recommended by a certified mold remediation expert) to eliminate any remaining spores. It’s crucial to stop the source of moisture.
I’ve witnessed this situation in the past. Both the moisture and mold seem to be originating from the plants.
Thanks for the helpful information, ! I had no idea about the potential risks of indoor plants causing mold on walls. Found the article interesting!
If those plants are alive, then it’s probably obvious, but don’t you think that watering them in that cramped corner would create humidity without proper airflow?
Mine did just that. I had a small leak further up on my roof that dripped down from the interior. We waited and checked the attic during the rain to locate it.
Dispose of the plants 🪴
Clean, dry and relocate the plants.
Wow, your little house has really grown up! Next time, please remember to knock before entering.
Right?
Haha, that took me a moment to figure out… lol
First, make sure to remove any residue, apply Concrobium while wet, allow it to dry overnight, then wipe with a Concrobium-soaked cloth. Once you’ve painted, spray Concrobium again to prevent new mold growth. Avoid using bleach-based cleaners as they can reduce the effectiveness of Concrobium, as indicated on the bottle. I’m also considering whether the curtains on the window are playing a role by trapping air and causing condensation and moisture build-up, which ultimately leads to the ceiling. If you have older, less energy-efficient windows, this could potentially be contributing to the issue.
Check outside to see if the gutters need clearing out. If they’re clogged, water might overflow onto that wall.
I’ve personally dealt with similar staining in my house. It turned out to be from rodent excrement seeping through the ceiling. Consider checking for leaks or rodents as possible causes.
Make sure to clean out the gutters and maybe invest in a dehumidifier!
Hey, remember not to point a fan or dehumidifier at the mold when cleaning. It can spread the spores around!
I’m suddenly not too worried about my fake Ikea plants anymore 😭
I’m just curious, is your climate mostly humid or rainy throughout the year? I ask because everyone is saying it’s the plants. I live in a dry climate and don’t have as many indoor plants.
At first glance, I thought these little guys were from Spirited Away. I’m just so exhausted.
I once moved my snack plant that is in a large planter and placed it near a corner, similar to how you have it. I’m not sure when it started developing a bit of mold in the corner, but honestly, I’m not sure if the plant caused it. It was a big coincidence! I have since moved the plant back to its original spot. Have the plants always been there or were they recently moved there?
The plants need water maybe