[AnotherUsername]

Greetings from Bellingham, Washington. Long time handyman, first time poster here. :thumbsup:

A friend is convinced she has mold growing in her living room and is concerned her whole trailer is going to collapse from rot due to it. I'm not so sure it is mold.

This is a 1960's vintage mobile home with 2x framing and insulation with vinyl siding. Electric heat and cooking. The suspected mold is concentrated on the inside of the walls, over the studs, very pronounced on the sheetrock nail heads and only on the north side of the building. You can see the black concentrations directly along the framing studs in the picture.

She tells me she keeps the house pretty much zipped up tight in the winter, however, there is a decent amount of infiltration through the windows and such. There is only a hint of blackening in the kitchen (no picture.)

The discoloration first started appearing about 8 years ago and was very faint. Each winter it darkens and becomes more pronounced. This year, we had a significantly more severe winter and coincidentally, she noticed soot from her oil candles forming on the ceiling. You can see two blotches on the ceiling above the oil lamps.

She says the lamps are burning almost all winter. (She likes the ambiance.)

Anyway.... I tell her there's a pretty good chance those black accumulations are not mildew and are probably soot condensing on the cold studs.

She doesn't seem convinced and fears the worst.

How can I prove it to her either way (mold vs soot?)

Thanks

Mike

 

[Chemist1961]

I think you can buy a swab kit and send it to a lab.
On the other hand, if she needs any elctrical done now is the time while you bcan see the studs

 

[ccarlisle]

That's neither mould nor mildew; it's a soot-like dirty substance that is in the air, from cooking and heating, just floating around. It's what gives you dirty carpets and furniture. It is stuck on the lines where the joists are because the joists are at a different temperature than the rest of the ceiling and condensation makes them sticky.

Wash with detergent and rinse well. Then reinsulate the ceiling if you can.

 

[Maintenance 6]

You nailed it when you mentioned the oil candles. They produce soot which condenses out of the air onto cooler surfaces such as the joists and nail heads. To be more exact microscopic particles of soot attach themselves to microscopic bits of water vapor which then condense on cooler surfaces. Oil lamps and scented candles are notorious soot producers

 

[Wildie]

You nailed it when you mentioned the oil candles. They produce soot which condenses out of the air onto cooler surfaces such as the joists and nail heads. To be more exact microscopic particles of soot attach themselves to microscopic bits of water vapor which then condense on cooler surfaces. Oil lamps and scented candles are notorious soot producers

Agreed!
i once had an apartment lessee that liked to burn candles!
When she moved out I had one hell of a mess on my hands.
I had to scrub all the walls with TSP then prime and paint everything.
Try doing this job in a 5 room apartment, over weekend, before next tenant moves in.
Not fun! I HATE candles!

 

[Maintenance 6]

I had a tenant do the same thing to me. And she was adamant about not smoking cigarettes. Not sure why. The soot from the candles was probably worse.

 

[ccarlisle]

Yup...well I have seen a house where no-one smoked and no candles were used. Bad insulation and our heating climate were the culprits.

 

[AnotherUsername]

Thanks for the replies and helpful advice!! :thumbsup::thumbsup: