mud through the chimney

[Sam]

I have the following problem with a friends house (she is an older lady). She told me that she has to clean the basement from mud that is coming through the chimey for the fireplace (the house has two chimneys, the fireplace one is not in use). First of all the chimney has no top cap - so that I will install first. To me it seems that there are also some guttering problems that I will try to solve.

Any other ideas what the problem might be? Thanks, Sam

By the way it's an older house (1920s)

[Joe Bobst]

Interior or exterior chimney? Is it really mud or decades of ashes?

Joe

[Sam]

an exterior chimney and it is mud (pretty wet)

[Joseph Meehan]

Maybe the remains of some animal nest. Normally mud does not fly up and into chimneys. :-)