Expert: James Ball - 12/19/2010

Question
QUESTION: James

I live in central Illinois and when we have snow on the ground and the night time temperature is under 20 degrees or so and the daytime tempature warms up with sun out my chase cover condensates and drips on the back of the firebox. It is a pre-fab Heatilator fireplace. I have had 2 fireplace/chimney contractors out and have gotten no answers. One of them replaced the chase cover and made sure everything up top was sealed. All of the bathroom vents are vented outside the attic space. If you take the vynil siding off above the roof line it is sweating underneath also. I have opened a hole from the attic to the chimney chase and it is open from top to bottom (2 stories plus the portion for the attic and what extends above the roof line). It has insulation on the house side the whole way, but the other 3 sides of the chase are only insulated on the first floor. I also have no firestops between floors. Any help would be great.

Thanks

ANSWER: Hello Jason, two thoughts here, one do you heat with natural gas? if so have that looked at (ton of moisture) second if the moisture is getting in, the top of a chase pan should have collars that extent up around the chimney pipes (this keeps water from getting in) then a storm collar on the pipe to keep the water from getting between the chimney pipe and collars, was this done?  
If t his was not done then install a louver in the top of the chase to allow the moist air to get out.
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, they should be able to help.
Hope this helps
James


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

QUESTION: James

I have a collar soldered into the chase cover and the storm collar over that. So are you saying to install a louvered vent on the chase near the top to allow the moisture out? Should I have any firestops in the chase? I currently don't have any. You can see from the attic all the way to the firebox. I was thinking there should be a firestop between the second floor and the attic. My chase is on the side of the house if that helps. Thanks Again.

Answer
Welcome back Jason, the way the chase pan is sounds right but can not tell for sure with out seeing it.
A louver near the very top or the chase on a wall might be the easiest this go do, but still have a certified sweep look at it and check with your local building department about "fire stop" requirements for your area.
Happy Holidays
James