Do I need to remove our unused chimney?
Melody Fronsdahl| Posted inGeneral Questionson
There is a short unused brick chimney in our attic. It has been closed off for years & does not go thru the roof. We had a metal roof installed and they did not put soffit vents back in…only vented at ridge cap….now I have a huge condensation issue. I have had blown in insulation removed and am having soffit vents installed…my husband says the chimney is adding to the problem due to bricks holding moisture. I think if we stop the condensation with proper ventilation that the bricks will not draw much moisture from the cold air. There are no leaks in the roof….only condensation, Should the chimney be removed…it is only about 3 ft tall. Thank you !
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Replies
Melody - The chimney should be removed, but not for that reason. It is a reasonably sized "hole" in your insulated ceiling, and is most likely a source of heat loss via air leaks as well. I'd consider removing down about 4' and resealing the ceiling to be continuous with the current ceiling( i.e.,replace the chimney with air tight drywall and more insulation).Those relatively small holes lose a lot of heat in an otherwise well insulated attic. Good luck!
Melody,
Adding soffit vents is a poor solution for your condensation problem.
The condensation is due to air leaks through your ceiling (the attic floor). Indoor air is humid, so the leaking air carries moisture. This is a very typical problem. The ridge vent is making things worse; the faster air leaves the ridge vent, the more air is pulled through your ceiling.
The solution to the problem is air sealing at the ceiling plane. I'm not sure why the blown-in insulation was removed -- it may have been excellent insulation -- but now that it's gone, you have an opportunity to seal all the leaks in your ceiling.
Taking away some of the chimney bricks -- demolishing the chimney to below the level of the attic floor -- will make your air sealing work easier.
Should you install soffit vents? Maybe -- maybe not. Doesn't matter much. The main issue is sealing the air leaks in your ceiling.
Here are links to two articles to help you with your work:
All About Attic Venting
Air Sealing an Attic
非常感谢! !由于绝缘被删除it having gotten so damp from the horrible condensation. Thus I opted to have it taken out - will spray down with bleach & replace with rolled insulation - once all of the other issues are addressed. Did find that the kitchen range was vented to the attic and not completely out the roof...so that is being corrected. Will look for other leaks ect. Appreciate your replies!!
What time of year are you getting the condensation and what climate are you in? If you are getting it in summer, it might be a different issue than if you are getting it in winter.
More than the chimney being a breach in the insulation, it's a huge air leak, which is probably the main air leak responsible for the high attic humidity.
What Martin said- cut it down to the ceiling level and install an air-barrier over it continuous with the rest of the air-sealed ceiling.
Now you know the real reason Santa is not delivering Christmas presents, how can he with a closed off chimney. So much for all that Santa does not exist hyperbole that is supposedly "common knowledge" :P
THE CONDENSATION IS COMING IN THE WINTER MONTHS WHEN THE HOUSE IS BEING HEATED.
THERE ARE GABLE VENTS ON BOTH ENDS & THE SIDES. MY HUSBAND TOOK THE CHIMNEY OUT TODAY!! GUESS I HAVE A MESS OF SOOT TO CLEAN UP!! HE WILL SEAL EVERYTHING OFF AND WILL CHECK OVER THE REST OF THE ATTIC. (SORRY ABOUT TYPING IN CAPS...I SEE BETTER THAT WAY) THANK YOU ALL !!
Thanks for confirming the problem is in winter. That means that what you are doing is the right thing. Good luck with the soot.