Expert: James Ball - 12/2/2008

Question
QUESTION: I have recently done extensive remodeling to my kitchen where I have a fireplace. In June, I had a new crown, tuck pointing and replaced three bricks in the fireplace. Tested great. No leaks. It's now November and am just getting ready to install a gas log burner. However, I've noticed a constant drip. Looked up into the flue and moisture all over the place. My chimney guy thinks it is condensation caused by heat going up the flue. I have a top closing damper and no appliances are vented to the fireplace. Right now I have the flue open and a fan blowing into the flue to hopefully dry it out. Any ideas?

ANSWER: Hello Theresa, a top mount damper will hold moisture in the chimney (not allowing it to breath) if water is still getting into the chimney.I would say have the fireplace flue checked and scanned during the next heavy rain to see if you find any?
You might also be getting moisture from cooking?
hope this helped
keep me posted
James

---------- FOLLOW-UP ----------

QUESTION: James,
It rained just a couple of days ago (decent rain, but not a down pour) and there was no difference in the volume of drips coming down the flue. I covered the fireplace with heavy plastic and tape a few days ago and still have the drip. This is like water torture. What do you suggest in place of a top mount damper?

ANSWER: Welcome back Theresa, first, is this the only unit in this chimney? if so get some one to cover the top of the chimney with a water proof tarp all the way down to the roof on all sides, for a a good rain and see if you are still getting the water in , if so then it is not the chimney, maybe flashing, or something else on the roof up hill or across the roof line (gutter, hole in fascia board...etc)did some one check the attic area  to see if there is a visible leak?
To find a water leak you may have to have some one run a hose, start by clogging the gutters and over flowing them,,and watch in the chimney then every half hour move the hose farther up the roof/chimney 1 foot at a time until you get to the top (do not run the water down the chimney) but go over the top of the damper cap when closed. all the while watching in side the chimney until you see it leaking. could take hours, days...hard to tell
hope this helped
keep me posted
James

---------- FOLLOW-UP ----------

QUESTION: James,
When I opened the top mounted damper(and left it open), no more dripping. Since I have a non-venting gas log system, I have installed sheet metal just above the firebox and used a high heat resistent mortar caulk to seal it all in. (Keeps my heat from going up the chimney)When I keep the damper closed, I have a very small amount of water dropping. When I open, I have none.

Answer
Welcome back Teresa, ok now you state you have a "non-venting gas log system" that produces a ton of moisture, when you have the damper open the moisture goes up the chimney, close it and it stays in the house. I am not a big fan of "non-vented gas logs"
it sounds like this set up was not thought out to well before installation.
I would have a local Certified Chimney Sweep (www.csia.org, there you can look up by zip code to find one near you) take a first hand look at what you have to see if it is set up right, safe to use and how (if it is possible) to correct it.
James