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I am about to start a kitchen remodel where I have been asked to fix an unrelated problem.
In many areas of the ceiling the there is shadowing on the ceiling where the ceiling joists are located. As I recall it is a sooty appearing stain on both sides of the joist fading as it gets further from the exterior wall. Maybe about two feet out. It seems to be contained to the single story portion of this split level house but appears sporadically in some first floor rooms with living space above. The most prominent stains are at the ceiling where it meets the exterior wall on an eave side of the the single story portion with roof only above the living space.
They have had there furnace checked, and she has told me she likes to burn candles, but not directly below these areas.
My diagnoses is that the attic above the living space was probably loose fill, and was either not installed heavy enough, or has migrated away from the exterior wall. The trusses are probably top chord overhang, which is also limiting the amount of insulation in these areas. There has been no history of ice damming. I think the lack of insulation is creating a cold spot on the ceiling allowing moisture to condense, creating a magnet for airborne particles. In the few places it occures where there is living space above, I would suspect the rim joist is not insulated.
Oh, this is a pulte house, and there is no access to the attic (yet!). I’m thinking providing more insulation where possible will cure the problem, as well as limiting the candle burning. They are tired of painting the ceiling every two years.
Any thoughts?
Tom
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I'm thinking along with you Tom, and considering whether the attic is getting a condensation problem, and the water is travelling down the trusses to the ceiling below. Is it a drywall ceiling? If so, any tape showing, or sponginess?
*Dear Tom,You and MD have a lock on this. Just one more element to consider. Every building where I have seen this effect has also had an uncontrolled moisture source as well.Scope the cellar, find the water, and tell us about it.Very interested, Fred
*IMO the minor condensation from the cool joists is grabbing any indoor pollution and leaving the marks. I had the same problem with a chronic candle burner, even the outlet covers on the exterior walls were sooted. You need to get as much moisture out, fix insulation errors, and cut the pollution(soot,dust,grease). Maybe add an outside venting range hood if there presently isn't one.good luck!
*Yeah, Mad dog,Its a drywall ceiling. But no tape problems. Fred, I believe its on crawl space in the offending area. I'll check that out when I get to the job.Thanks for the input, I'll let you know what I find.Tom
*My expereimce as a home inspector (and seeing this regularly, say 10-15 times a year) is that it's usually from soot (candles, bad furnace/boiler/"ventless" logs/kerocene heater) AND slightly cooler surfaces.Soot sticking to condensation at the slightly cooler areas is one theory, the other is increased air movement/currents at temperature differentials leads to increased air particle impacts at those locations. I lean toward the 2nd theory, but can't "prove it."Personally, I haven't seen (or maybe it's just 'noticed') this probelm particularly associated with moisture problems when its soot.When it's mold (use bleach to distinguish - bleach will lighten the mold but not the soot), it's a moisture and condensation problem.
Hopefully this isn't a dead thread.
I built a glass studio two years ago. At one point they had trouble with the furnaces and generated some soot that left the ghosting you're talking about. I can see everybit of framing; blocking, headers. rafters, plates and studs. Construction is 2x6 framing 2' oc, 11 7/8 BCI roof rafters 2' oc, with dense pack cellulose in the vaulted ceiling and wet spray cellulose in the walls. Any comments?
Dan.
No especially helpful comments; I hear it can be a bear to clean; many recommend using the stain blocking type primers Kilz, BIN, etc.
Good luck.
The cleaning is simple, wash with TSP (sodium tri phosphate from any paint store) before repainting.
The soot is more likely to cling where moisture from condensation is present, as is dust and mildew - so it's a combination connected to moisture and cold.
Insulation helps but it is worth checking for moisture sources.
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