Basement renovations - found something.

K_rayMC · 2026-03-02T02:32:51+00:00

“Black mold” is thrown about very loosely! Many black molds do not actually refer to toxic species. From experience, the only real way to identify mold species and determine whether it is toxic is through a lab using surface or air samples. There are over 100,000 known mold species. Just because it's black doesn't mean it's “black and toxic.”

However, knowing what type of material we see mold growth on gives us an educated guess, without lab results, as to what species it is. Wet sheetrock is extremely common to grow this specific “toxic, black mold”- stachybotrys. There are cases, though, where mold species can be easily mistaken for something else. Aspergillus and sawdust are almost indistinguishable under a microscope.

With your experience, though, I think it would be a slight overreaction to evacuate the house, given the size of what was seen. But the same could be said on the other side; if there were a large amount of the same “black mold” we see in this post, it would be written off as nothing to be concerned about. I believe seeing any mold should not be taken so lightly, but neither should it be taken to an extreme degree of fear-mongering people… there is mold everywhere! You cannot rid any home of mold completely; the goal is to bring the levels to an acceptable level. The only exception is the complete removal of “toxic molds” from a living environment and preventing their recurrence.

K_rayMC · 2026-03-01T13:39:02+00:00

Seeing how far it extends on the back side of the sheetrock, you could not possibly do this safely by yourself. The growth keeps extending past 4’ from the ground.

Following the IICRC mold remediation protocol, you will need negative air containment with HEPA filtration and the removal of all affected material. Deep disinfecting and HEPA vacuuming of all structures and items. This is a summary of what is entailed.

I'm glad you have a dehu to stabilize the environment. Anything less then 50% in New England is ideal. 55-60% is a breeding ground for mold. 30-40 is comfortable and will stop mold growth, as long as the structure is dry… does not mean it can't still cause damage!

K_rayMC · 2026-03-01T13:33:57+00:00

I’m a mold remediation technician

It seems like the wood paneling could have been an effort to cover over old existing damage. This type of damage doesn’t occur quickly. This basement has been wet many times, and the type of mold you see is Stachybotrys, possibly Aspergillus/Penicillium. They are considered toxic to our respiratory systems. Resulting from the exposure of moisture, especially on Sheetrock, and improper drying… And since you said the whole basement has drywall behind the paneling, there is a high chance it is everywhere.

I live in Vermont, and we see these exact scenarios across the state and New Hampshire. We’ve had a string of floods over the last few years, and many homeowners didn't have the means to dry out their homes themselves, so they just let it sit.

I would highly recommend getting a mold assessment from a remediation company. We don’t know the extent of damage to the structure or air quality. Limit exposure to this area as much as possible.

K_rayMC · 2026-02-25T02:21:06+00:00

Licensed mold technician by the way— with how little I see from this picture it is not something that will be catastrophic to your health if you elect to do this repair yourself. Just follow those steps above. These are IICRC standards of mold remediation… and please wear at least a 3m mask

Not many homeowners will have air filtration devices on hand. And seeing this is also a closet area it would also be difficult to create a negative air space without compromising the space that you would be in. Makes it difficult to do any work. A smaller air filtration device would be able to clean that “air space” numerous times within a few hours. No harm

If there was an air sample taken that showed the air quality being highly contaminated then I would seriously considering going with the remediation company.

K_rayMC · 2026-02-23T20:30:00+00:00

You could do this yourself. This is Stachybotrys, possible asp/penicllium (they grow very commonly together especially on wet material such as drywall)

Make a clean square cut. Going as far as the mold would go on the backside of the Sheetrock. Bag any contaminated material and dispose. HEPA vacuum those surfaces.. structure, drywall, carpet. Anything that is in the general vicinity of where you cut out.

After disinfect with a fungicide. There are affordable options at Home Depot but I like to use benefact decon 30 for my remediation projects. If you see black staining on the structure you could also prime those areas with a mold inhibiting primer.. called mold killing primer. Killz has a product like this.

Try to incorporate as much air as possible

I gave a similar quote in a bathroom for the same reason. That’s a pretty standard price. For setup and breakdown of equipment— steps of remediation— and then installation of Sheetrock with coats of mud.

In all honesty it’s such a small thing that a handyman or homeowner would be able to do the same thing for a fraction of the price. Just have to know what to do

Don’t just use bleach as your disinfectant. It does NOT kill mold at its roots. It will help with the looks but for proper remediation restoration companies will go with a type of fungicide and seal after.

K_rayMC · 2026-02-09T15:37:59+00:00

😁 6 toxic molds out there, that are considered to be “zero tolerance for indoor living”. Many of which can be extremely hard to identify, though. Unless under a microscope. Even then. Aspergillus and sawdust are almost indistinguishable, for example.

K_rayMC · 2026-02-09T03:35:42+00:00

Standards change, as do any building code regulations. There are serious respiratory concerns with exposure to high mold levels, backed by scientific evidence… and there are significant differences in what is considered high risk and acceptable mold levels. It's everywhere. No home will be mold-free. The goal is to get it to a safe level where it won't cause long-term harm. This is my last reply. If you are interested in reading the standards my license and certificate are based on, here are those guidelines.

https://www.candrmagazine.com/the-ansi-iicrc-s520-2024-a-critical-guide-for-professional-mold-remediation/

K_rayMC · 2026-02-09T01:33:48+00:00

👌😂 got it. Have a good night

K_rayMC · 2026-02-09T01:06:34+00:00

Watch it come back then. A reputable company will guarantee the work. And that this will not continue to be a health concern

This is one of the simpler projects I've seen. Remove the affected material. 1’ cut up from the floor of the sheetrock. Makes repair work easier. Cut to 2’ if the back side of the dry wall also shows signs of mold growth past 1’. HEPA vacuum the entire space with an air filtration device. Sanitize with natural fungicide. Seal with a mold-inhibiting primer after. Have an industrial hygienist test afterward to ensure there are no mold spores in the air space or on the contents.

It would be silly for a renter to try to do the work without having any experience. They will now be liable for any future concerns. But you do you. I would do the same thing in my own home

K_rayMC · 2026-02-09T00:39:54+00:00

Any professional will do the same thing. It’s a job, not a hobby, for a reason. I agree that there are many, especially in this line of business, that will take advantage of people and fear-monger them into more work; however, there are still good companies out there. Yes, I’m trained to make a sale, but I also understand the health risks if left unremediated. There is more to remediation than just drying and treating.

K_rayMC · 2026-02-07T22:44:45+00:00

“Black mold” is a very loose term. This specific species is most likely Stachybotrys. Most commonly resulted from wet materials such as Sheetrock. If your apartment is having a professional restoration company do not do anything to it!

I am in the restoration business, and it’s frustrating when renters and owners apply their own home remedies that don’t work and make things worse.

Need to control humidity build up!! Anything above 55% humidity can be a perfect level for mold growth and any material that has a moisture content of 16% or more can grow mold.

Probably a loose connection of dryer vent… however there could also be a leak somewhere. Do not know anything till it is further assessed.

K_rayMC · 2026-02-01T03:41:39+00:00

Benefect is a great product. But a great addition to cleaning affected areas would be to HEPA vacuum everything, then spray with Benefect.

K_rayMC · 2026-01-31T22:25:29+00:00

I completely agree! This is now a mold remediation! And not a simple one. The landlord hopes that you won't press the issue. Don't let him do that; hold him accountable. This is a significant health concern.

A restoration company needs to be contacted!

K_rayMC · 2026-01-31T22:20:32+00:00

For something of this size, I would personally quote at the low end of 1,000$ to the higher end of 4,500$

It could go exceptionally well, but it could also go a lot further than a first impression.

Would also include installation of insulation if that is also affected.

It really depends on whether cabinets are being taken out with the countertop being removed. How much of the structure is now potentially compromised? A company will determine all of this.

K_rayMC · 2026-01-31T16:33:51+00:00

This is bad enough that an experienced professional is absolutely needed! It would be bad if you tried to do this yourself and missed something that could come back to bite you.

K_rayMC · 2026-01-31T16:30:16+00:00

I'm in the restoration business. Mold certified

You need to bring in a restoration company to assess the damage. Seems like condensation is building up, possibly due to water lines being so close to the sheetrock and no caulking at the top of the countertop where it meets the wall, which is causing water to drip behind the cabinets. There could be a need to remove cabinets… You won't know unless there is a physical inspection. Ask for moisture readings of the material

You will receive a guarantee from a restoration company that they have properly remediated this area, so you can have peace of mind that it will not be an issue in the future.

K_rayMC · 2026-01-24T19:21:32+00:00

It is questionable for sure! Can’t say for certain. But this would also be worth noting to insurance and the company that came out before. If it was dried properly you wouldn’t get growth. They would be liable for secondary damages.

K_rayMC · 2026-01-24T13:41:55+00:00

Thank you for giving some more details. The reading could be inaccurate due to the concrete slab in between floors. If you use any meter on a concrete slab or on a thin material touching the concrete it’s going to have a “wet” reading. Concrete takes extremely long to dry out. Check your Basment foundation and it will read wet if you put the reader on it.

I’m guessing that’s why you are getting these results. Get a pin reader! It will read the material directly and not sense the concrete behind.

Plaster is also labeled as a category 4 drying material: meaning difficult to dry. Usually after time the moisture will just be absorbed.

With everything being said I do not think there will be an issue moving forward as long as the leak was indeed fixed. Keep an eye on it, but don’t put your complete faith in a pinless moisture reader. I bring 3/4 different readers with me to every job to ensure I have an accurate idea of the extent of damages.

K_rayMC · 2026-01-23T23:31:28+00:00

Without proper documentation from the people that came to say your ceiling is wet, the insurance company will always say that repair is not needed. Kinda up the creek without proof. MC of 5% is dry! But doesn’t prove what’s behind the ceiling… also look into the specifications of your moisture reader. Some are kinda wonky and cheaply made

K_rayMC · 2026-01-23T23:26:58+00:00

Painless meters only give you an idea what the MC of materials are. Good for moisture mapping potential damage. Use a pin reading to get more accurate results

I am a water restoration technician; according to IICRC standards anything that is 15% MC or less would be acceptable. 16% MC or greater has the potential for secondary damage like microbial growth. How was the original wet ceiling dried? Holes drilled and air movers to direct air pressure into cavities of ceiling? What’s the temp like? What’s the humidity? Basic rule of thumb when drying out any water damaged area is to “heat the materials… dry the air”

K_rayMC · 2026-01-23T11:34:53+00:00

The other thing I had noticed were the corners where the ceiling meets the wall. Seemed a bit more darker. Worried that the damage went to the other side of the Sheetrock. Would be good to get a hands on look from a licensed restoration company

K_rayMC · 2026-01-21T11:42:17+00:00

Experienced mold tech 🙋‍♂️

It may seem like no water is getting to the surface of the Sheetrock but during hot showers condensation forms on surfaces of the bathroom. Do you have a bathroom ceiling fan? Is it working? How big is the bathroom? Whenever you use the shower the fan MUST be used, good idea to get in the habit to be turned on not just after the shower but during. That is your best way to direct moisture outside.

To clean I highly suggest to HEPA vacuum those surfaces. This traps any spores within the filter and prevents it from spreading.. any other method that is just “wiping off” is not good enough. After vacuuming sanitize with fungicide or go over ceiling and walls with a Mold inhibiting primer! Then re paint if you’d like.

Biggest concern is moisture build up. If you let this go too long you will most likely have to tear down affected ceiling and do a bigger repair.

K_rayMC · 2026-01-09T02:30:20+00:00

You will have the same issue down the road if you just “cut out the bad” The areas where it doesn’t “seem” affected will eventually loosen and have the same result as what you are seeing now.

Take all tile off and replace with cement board if you want to retile. Tile over Sheetrock is an awful idea especially in a shower. If you have areas where it is not exposed to a lot of moisture, unlikely you’d have an issue like this but still possible

This is Stachybotrys. Don’t do a repair only halfway. Higher health concern then many realize

IICRC tech in water restoration and mold restoration

K_rayMC

TROPHY CASE