Software
Houzz Logo Print
webuser_327408063

Plaster over chimney

6 years ago

Hi,

Bought a house 3 months ago, built in 1954 and vacant for two years. Water damage on walls in various parts but the roof was new. I assume the old owner replaced the roof but didn't fix the damage as I observed and nothing got worse. All my plaster patches have held up except the area around the chimney (mainly where chimney wall meets the roof). The plaster over it never seemed to completely dry. Eventually it would discolor and bubble. I brought a roofer in to inspect: no hole around the solar panel legs, chimney flashing is caulked, no moisture in the attic. I peeled off the new plaster, drilled a small hole in the chimney brick, and observed while he ran a hose over the roof and chimney. No leak! I tried patching the hole again with gyprock 20 and same problem.

Any suggestions? Could it be condensation? I'm wondering if the warm air inside condenses on the cold brick behind the plaster. Then that moisture gets absorbed by the plaster. The rest of the chimney area is fine and looks covered with a cement stucco.





Comments (3)

  • 6 years ago

    That is certainly a mysterious issue. We have something very similar with a part of a ceiling that keeps getting plastered and painted, and then it is disintegrating like water is still coming through, but just like you, our roof is new and the chances of leaking are slim to none. Condensation is a good idea. You might want to re-do the chimney entirely with something different for a covering. A lot of people are re-doing old chimneys by putting slab-type stones over them, and you could also brick it out with a new layer. There are also treatments that go directly over old brick to change the color or spruce it up if you wanted to go through the painstaking process of removing all the stucco. Maybe another commenter will have a better idea.

  • 3 years ago

    Hi, we have almost the same issue in our home. Had a new roof install and the issue with plaster on the 2nd floor wall never really dries out and keeps bubbling. We are still struggling to find the source of the water. Had a chimney company to come inspect and he said it most likley cause by the lack of lining in the chimney. Before we throw money down the endless bottom of fixing the issue, have your resolve yours? If so, what was the issue so that we can do a cross comparison. Thanks.

  • 3 years ago

    We had a similar issue. We had the attic insulated and spray foamed which caused a negative pressure situation. The chimney was drawing up cold air from the basement and into the attic. The chimney was so old 1907 home, and the tuck pointing needed to be redone. So we opted to dismantle the chimney which was waaaay too easy. Bricks were very porous and disintegrated into our hands. Then we filled the old chimney hole with fiberglass and spray foam and no more negative pressure. Now we need to fix the ceiling.