In a recent discussion from our Q&A forum, Chris Ermides tries to determine what caused severe deterioration of a brick column in the basement of his Victorian home. Chris knows that his basement could use some moisture remediation, but he is puzzled that none of the nearby brick walls have similar signs of decay. Fortunately, the chimney that the column once supported is long gone, and the load of the adjacent beams rests comfortably on lally columns, but Chris is still determined to solve this mystery.
Michael Maines tells Chris that either basement-dwelling livestock used the efflorescing minerals in the column as a salt lick (JK), or we’re seeing a phenomenon called “rising damp.” The whitewash on the bricks above is actually one way of dealing with it.
Michael Chandler thinks the water that caused the spalling may have entered through the old chimney due to a poorly maintained cap. Michael suggests that the epicenter of the damage may be where the bottom flue tile, or some other obstruction, held the water until it worked its way through the brick.
James Morgan doubts that rising damp would occur so high above the ground (especially since the foundation walls don’t show similar deterioration). He agrees with Michael Chandler that water trapped in the old chimney may have been the culprit — possibly from a blocked ash cleanout that has since been filled in. James goes out on a limb to suggest a third scenario: perhaps someone started to demolish the old chimney base but had second thoughts.
I also pointed Chris to Joe Lstiburek’s recent Building Science podcast on efflorescence.
UPDATE: EXPERT OPINION FROM BILL ROSE
Green Building Advisor’s Technical Director, Peter Yost, went to the rising damp master, BIll Rose, to try to solve this once…
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