Originally Posted By: kmcmahon This post was automatically imported from our archived forum.
At first I thought this was rusty condensation stains from the ductwork inside the boxed out ceiling(theres a name for this on the tip of my fingers, but it eludes me right now for the correct term)., but after rubbing it, it wiped off and had an oily feel to it. Just tiny beads at the corner of the ceiling.
Originally Posted By: dedwards This post was automatically imported from our archived forum.
Around here that box is also referred to as a “soffit” and I agree it is probably nicotine. Anywhere there is condesation the nicotine “floats” on the moisture droplets and when it dries it leaves the beads of oily nasty residue. I did an old house where even the kids and dogs must have smoked because those droplets were everywhere, especially in the bathrooms and kitchen. You could smell it before you opened the front door. The smell was clinging to me so much so that when I got home my wife could smell it.
Originally Posted By: rcooke This post was automatically imported from our archived forum.
I think the word you are looking for is ghosting . It some times shows where all the 2 by fours are in the wall as this area is very slightly cooler then the rest of the wall it attracts the air born dust. This is very noticeable in homes where people burn a lot of candles
Originally Posted By: Caoimh?n P. Connell This post was automatically imported from our archived forum.
For what it?s worth?
I see this quite a bit in indoor air quality investigations. I agree with the smokers and candles burners; also add to the list cooking aerosols. It seems that as the condensation occurs, it also drops out particulates and water solubles onto the surface. The higher the concentrations of these indoor contaminants, the more noticeable the effect.
However, this should not be confused with ghosting which is particle deposition onto surfaces via thermophoresis.
(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)
Originally Posted By: mlong This post was automatically imported from our archived forum.
kmcmahon wrote:
Soffit was the term I was looking for!!! 
For what it's worth, in my neck of the woods, a soffit usually refers to the flat area under the eaves of the rafters, and the boxed out area around ductwork, etc., is a bulkhead.
It's interesting how different locales develop different wording for things.
Originally Posted By: Jay Moge This post was automatically imported from our archived forum.
I know, I Know, “old post”.but i couldn’t believe no one got it. it’s rust bleeding threw from the drywall. ya know those angled strips used to finish an outer angle on drywall corners? called “corner beads”, and moisture is penitrating the paint and compound and rust is bleeding threw.
condensation forms from warm ducts inside and cool moisture outside (…the inclosure)
Originally Posted By: pbolliger This post was automatically imported from our archived forum.
Jay Moge wrote:
I know, I Know, "old post".but i couldn't believe no one got it. it's rust bleeding threw from the drywall. ya know those angled strips used to finish an outer angle on drywall corners? called "corner beads", and moisture is penitrating the paint and compound and rust is bleeding threw.
condensation forms from warm ducts inside and cool moisture outside (...the inclosure) 
Not always the case Jay, It could be a plastic corner bead also. The droplets are common in a small room like a bathroom or places that have more moisture like a laundry room . You could use a magnet to find out if it is a metal corner bead.
I have seen this on walls in a small bathroom when a "hot" shower is used and the steam vapor condensates on the colder walls. No venting to the outside so that is a good reason to vent bathrooms to the outside.
The color of the droplets are brownish . A newly painted bathroom to boot and not at the corners too.. 
Originally Posted By: Jay Moge This post was automatically imported from our archived forum.
what you just described totaly supports the posibility that it is rust bleed threw. they probably painted over the old stains, a few showers and vuala. look i’m not trying to discredit anyone, all i’m saying is that rust bleed threw is the most common reason for such marks and i don’t think anyone mentioned it. no harm intended.
Originally Posted By: pbolliger This post was automatically imported from our archived forum.
Jay Moge wrote:
what you just described totaly supports the posibility that it is rust bleed threw. they probably painted over the old stains, a few showers and vuala. look i'm not trying to discredit anyone, all i'm saying is that rust bleed threw is the most common reason for such marks and i don't think anyone mentioned it. no harm intended. 
I am not disagreeing with you Jay, I do agree in part that this could be the result of a metal corner bead too but what makes this profession so darn subjective and complicated is the fact that there are so many possibilities and that has a tendency to make us seem wrong at times.
As for my example: It was my house and my own re-model job so I went above and beyond the quality of what is normally done.
I saw the same conditions after a shower. Most of the wall had water vapor on it but the color changed as the water vapor was evaporating and it left traces everywhere.. Could be a chemical in the paint I used or something in the air added to the vapor only to be visible after drying.
Originally Posted By: Jay Moge This post was automatically imported from our archived forum.
gatcha. I only mentioned it 'cause no one els did. thanks for the insight, i’m always looking for all posibilities and then with a little deductive rasoning, find the most probable cause and solution…with that i’m all out of big word, but were on the same page.
