Between the spalling bricks and a persistent leak that has damaged a mudroom ceiling, the chimney on Page Hyler’s 1900 farmhouse is proving to be a problem that just can’t get fixed.

“We have had damage around the ceiling and wall of the chimney that I now know is efflorescence,” Hyler writes in a post at Green Building Advisor’s Q&A forum. Caulking the flashing at the roofline helped, at least temporarily, but Hyler eventually called in an out-of-town company to inspect and seal the bricks. Problems persist.

“I contacted someone else who refinishes old houses in the area and he thinks that we should patch up the bricks and repaint [them] with an oil-based paint because the chimney looks to be in decent shape otherwise,” Hyler writes. “He thinks the damage in the mudroom is the flashing around the chimney.

“I was wondering if there is efflorescence under tha painted brick would the oil paint suggestion solve problem or do I need to tear down the chimney and rebuild it.”

As if the situation wasn’t problematic enough, Hyler is planning to sell the house. Should that change the repair strategy?

Most likely causes: bad flashing or flue-gas condensation

Faulty flashing is one possible culprit, says GBA senior editor Martin Holladay, but it also could be moisture resulting from the condensation of flue gases.

Leaks at the intersection of chimney and roof aren’t at all uncommon, and while there are several possible corrections, Holladay thinks the most reliable way is with a technique called through-chimney flashing. “Proper installation of through-chimney flashing requires all of the bricks above the roofline to be disassembled,” Holladay writes. “After the flashing work is done, the chimney top can be rebuilt with the old bricks or with new bricks.”

Condensation…