Fireplaces, Heating Stoves, Flues and Chimneys - Pellet Stove burning too rich

We have a friend with a pellet stove that was installed last year. She has it in the basement of her home. The walls have a black streak at every stud on the north and west walls of the rooms. It is only striped on each stud and shows on the painted wall every 16 inches. We were wondering what the cause could be. Does anyone have this same problem? Very unusual looking. We thought perhaps the chimney was leaking in the wall and was showing up on the outside of the stud or perhaps the studs are damp and are drawing the pellet dust from the burning stove. Any ideas?

sounds like moisture wicking through the studs and showing up as mold, see this article for more info.http://www.eere.energy.gov/buildings/building_america/pdfs/db/35017.pdf

if we're not supposed to eat animals why are they made out of meat?

We have a friend with a pellet stove that was installed last year. She has it in the basement of her home. The walls have a black streak at every stud on the north and west walls of the rooms. It is only striped on each stud and shows on the painted wall every 16 inches. We were wondering what the cause could be. Does anyone have this same problem? Very unusual looking. We thought perhaps the chimney was leaking in the wall and was showing up on the outside of the stud or perhaps the studs are damp and are drawing the pellet dust from the burning stove. Any ideas?

I have and many other homes where I live have those stains on my roof on the north side because the sun never gets there to dry out the moisture. If you are getting it inside the studs it must be excessive moisture. Perhaps water runoff from you roof is accumulating to close to your home.
I suggest you wipe that down with some kind of bleach type cleaner ASAP before it gets to be mold. Sounds like a good spot for e dehumidifier.
good luck