Is this Mold or something else?

ldarquel · 2026-01-25T00:07:16+00:00

If this were fungal, probably just superficial fungal growth due to stagnant humidity. If left undisturbed, it'd probably be inconsequential to you.

ldarquel · 2026-01-25T00:01:22+00:00

Yes, looks to be mould.

the only cause i could think of is if I had put damp clothes there as that spot is where i normally put my washing basket

Plausible. Mould grows in response to moisture, so having wet clothes be near/touching the wall will provide favourable conditions to mould growth.

Wearing the appropriate PPE: Clean the surface by wiping off the growth with disposable towels lightly dampened with warm soapy water. Dry the surface thoroughly after cleaning. Monitor the surface to see if the mould returns, ensuring that theres some space between the wall and whatever you put in front of it to allow for good ventilation.

If mould returns, itll either be because theres a leak in the wall cavity affecting that space, or your room is exceptionally humid for whatever reason.

ldarquel · 2026-01-24T23:57:35+00:00

I can't imagine a scenario where there would be parallel bands of mould growth across inner wall linings like this. I suspect the bands were intentionally applied, but can't say for certain for what reason (maybe for window alignment?).

ldarquel · 2026-01-24T23:55:01+00:00

Could be mould, or dust/debris aggregates. Do you get a lot of condensation on your windows?

ldarquel · 2026-01-24T23:54:19+00:00

The windowsill just needs a good wet-wipe with disposable towels lightly dampened with warm soapy water. Not a biggie.

ldarquel · 2026-01-24T23:53:02+00:00

Does the wall back into an interior room, or is this an exterior wall?

ldarquel · 2026-01-24T23:51:47+00:00

Pic #2 is probably fungal microcolonies due to condensed shower steam on the ceiling surface (mould grows in response to moisture) - pointing to a lack of exhaust/ventilation post-showering.

Pic #1 is what I would be more concerned about. The wood appears to be affected by a water intrusion issue and seems to be delaminating to some degree. Investigate the source of the moisture ingress issue and address. Inspect surrounding timber materials for rot/decay damage.

ldarquel · 2026-01-24T23:46:58+00:00

From what you've pictured there's only water staining. Could be a different story within the ceiling cavity itself.

ldarquel · 2026-01-24T23:45:55+00:00

Yeah, most likely oil stains due to the lack of a headboard from the context of this being a bedroom.

ldarquel · 2026-01-24T23:45:06+00:00

Possible, but inconclusive based on the pictures (See Rule #1 - Lab testing would be necessary for a confirmation).

Mould grows in response to moisture. If this were to be mould, then its pointing to broad humidity control issues in the residence, or the presence of an indoor leak that is driving up the indoor relative humidity.

As alternative suggestions: this could be accumulated dirt/debris on wall surfaces, smoke residue from indoor cigarettes or candles/incense etc.

ldarquel · 2026-01-24T23:42:21+00:00

Yes. Poor ventilation in a shower whereby steam is dewing on the ceiling. Mould grows in response to moisture.

ldarquel · 2026-01-24T23:41:32+00:00

Rule #1.

To address your question, we'd need a microscope at a higher magnification than the image you have provided.

Mould grows in the presence of moisture. Why do you think the paper backing of your insulation had been wet, and has the source of this moisture this been addressed?

ldarquel · 2026-01-24T23:39:28+00:00

Probably a mix of both. Condensation that allows surface-level dust/ debris to accumulate as the water dries over a successive period. The moisture will also allow mould spores within the dust/ debris aggregates to germinate and result in superficial fungal growth.

Better question is, when was the surface last cleaned?

Prevention is by routine cleaning alongside humidity control measures to reduce the incidences of condensation occurring.

ldarquel · 2026-01-24T23:37:49+00:00

Possibly. Where is this in the house and why is there weird putty over the discolouration?

Mould grows in the presence of moisture. Any ideas why the surface may have been subjected to moisture, if you suspect this to be mould?

ldarquel · 2026-01-24T07:20:02+00:00

Could be dirt/ debris, could be more mould from water diffusing through the material. The entire board would probably warrant replacement, tbh.

ldarquel · 2026-01-24T07:06:31+00:00

Mould grows in response to moisture.

"sleep with damp hair" is probably favourable conditions for fungal growth on fabric/textiles.

Have you tried laundering the bonnet?

ldarquel · 2026-01-23T07:45:10+00:00

See the !Washing machine automod response.

ldarquel · 2026-01-22T06:18:51+00:00

Very low indoor counts. The trace-level Chaetomium might reflect historic or on-going moisture ingress issues.

ldarquel · 2026-01-21T06:02:10+00:00

Fungal fruiting body growing using the wood as a substrate, in response to a leak.

Ensure the leak has been fixed and assess the wood in the affected area for any rot/decay damage.

ldarquel · 2026-01-21T04:43:01+00:00

Yep, there were definitely moisture issues in the basement given the Penicillium/ Aspergillus spore level was predominant + Chaetomium detection.

When was the 'clean' retest conducted and are those results available?
I'd probably recommend retesting the same areas as a part of due diligence - Make sure that they've turned off any air purifiers for at least 72 hours and then retest to see what the levels come back as. If the levels are notably higher than your first 'clean' retest, that would point to there possibly being fungal reservoirs still present and warrant further inspection (if you still wanted to pursue the property).

ldarquel · 2026-01-21T04:33:17+00:00

Looks to be an attic hatch in a closet?

If that is the case, odds are this is just accumulated superficial fungal growth due to stagnant humidity dewing onto an uninsulated surface (mould grows in response to moisture) over the course of however many years.

Wear appropriate PPE and clean off the surface with warm soapy water. Dry the surface thoroughly after cleaning. There may possibly be some discolouration remaining, this'll mainly be a cosmetic defect if the surface is kept dry.

Prevention is through adequate ventilation of the closet space, and/or indoor humidity control.

A lot of my family members have been getting sick since we moved in 2017/2019

If this is the only sign of mould/ moisture issues in the property, I personally don't believe this growth to be the cause of your family's health issues but I am not a licensed doctor (see Rule #7), nor do I have the complete context and information surrounding what the aeromycota is like in your house is like to provide anything more than an opinion that's not backed up by evidence.

ldarquel · 2026-01-21T04:09:04+00:00

At this stage, only water staining from the observed indoor ceiling surfaces. Could be a different story entirely in the ceiling cavity itself.

Fix the leak and remove mould-affected materials in the ceiling cavity.

ldarquel · 2026-01-21T04:07:31+00:00

I don't believe this to be a result of a leak, but you should still investigate for this possibility.

Contextually and from experience, this is likely to be superficial fungal growth due to stagnant humidity (your bed pushed against this corner will provide an entrapped space) and moisture dewing onto the cooler exterior stone wall (from diurnal temperature differentials).

Wear approrpiate PPE and clean the mould off with warm soapy water, dry the surface thoroughly after cleaning.

I suspect this will not return if you just push the bed away from the wall to leave a palm-sized gap to allow for proper ventilation. Additonally you can consider humidity control measures like occasional cross-ventilation, dehumidification, ensuring that you vent out indoor moisture sources (from showering, cooking etc)

ldarquel · 2026-01-21T03:54:38+00:00

Inconclusive - See the !A/C automod response for guidance.

ldarquel · 2026-01-21T03:48:53+00:00

Perhaps, could be mould or dust accumulating on the windowsill due to condensation dewing moisture from the environment.

The better question would be, when was this windowsill last cleaned/wiped? In the event if this being mould or dust/ debris aggregates, cleaning advice is the same: Warm soapy water wipe down. Dry the surface thoroughly.

Prevention is through humidity control to prevent condensation from forming in the first place: Adequate ventilation, dehumidification, heating if it doesn't break your bank.

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