few weeks back, I replied to a reader’s question about
"ghost shadows" on his ceiling.
isn’t as spooky as it sounds. The reader was asking
about paint he could use to hide the lines, which
reappeared after he had painted the ceiling three years
course, I responded to his request for a paint
recommendation by suggesting a shellac-based product
that I have used to cover water stains from leaks that
have been repaired and to keep knotholes from bleeding
through finish coats.
Gross, a Cherry Hill, Pa., home inspector, saw the
column and offered that the "ghost lines" the
reader was trying to cover with paint "are simply
the collection of airborne particulate and can simply be
is not necessary, said Gross, of Engineers for Home
suggested that the ghost lines were more noticeable now
because a gas fireplace has been operated during the
discoloration is often heaviest nearest the fireplace
and lessens as one moves away from the fireplace, he
is what Gross said in a home-inspection report regarding
such discoloration, which people often confuse with soot
contamination in a house:
‘shadowing’ present on the walls and ceilings is the
result of the collection of airborne particulate.
is a term used to describe the collection of airborne
particulate on interior surfaces where the particulate
has collected as a result of temperature differences in
the interior surface.
surface where the wall is well-insulated does not get
cold enough to allow moisture to condense. The surface
where the wall is not well-insulated gets cold enough
(below the dew point) that moisture condenses on the
airborne particulate adheres to this condensation and
collects over time, resulting in ‘shadows’ on the
other side of the home’s framing members.
walls and ceilings (ceilings with an attic on the other
side) are by far the most common locations for
to know. It certainly will save on painting.