I have a serious condensation problem within my chimney chase. This is obviously a construction/design problem but I'm at the end of my rope as to how to fix it. I have contacted two local dealerships but neither one will return my calls. I have contacted the chimney vendor and hired a couple of local contractors but no one has been able to identify the problem. I'm wondering if anyone has any suggestions as to the best person to determine a proper chimney chase design in a specific situation (my design/construction would appear to comply with all the general drawings I have examined). I thought the fireplace installers would be the best ones to determine the specifications; I can understand that they may not be willing to undertake the actual construction or modifications but they should know what is required. Obviously there is some kind of design/construction problem and I'm surprised it was not identified at the time of the original install. Anyone have any suggestions? Thanks
Chimney Chase
- Thread starter BatocheBob
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Yes. The spray foam covers the underside of the roof deck. The chase is wood framed beginning at the vaulted ceiling and extending up about 4 ft and then through the roof for another 4 feet or so. Where the spray foam meets the chase it wraps down the sides of the chase to the ceiling. That portion above the roof line has no insulation and is covered with an uninsulated sheet metal pan. The bottom of the chase where it meets the ceiling is closed in with rigid foam insulation and spray foam. All seams and edges on the fire stop are sealed with hi-heat silicone. Thanks
I figured it was spray foamed...
I've seen this a lot lately. Since your house is spray foamed, all the moisture is trapped inside the envelope of the home. The house can't breath like older homes, so the moist air is drawn to your chase, where it condenses. The chase is acting like a chimney for your home, air can't escape anywhere else.
I've seen this a lot lately. Since your house is spray foamed, all the moisture is trapped inside the envelope of the home. The house can't breath like older homes, so the moist air is drawn to your chase, where it condenses. The chase is acting like a chimney for your home, air can't escape anywhere else.
kennyp2339
Minister of Fire
So what do you recommend to cure this? I've heard about new homes being so tight that they have to incorporate a air changing system (mechanical vent) ? would that fix the op's problem?
Don't know. It's a tough one!
I would completely isolate the chase from the rest of the house, insulate above the firestop and seal up all the cracks with silicone.
Webby,
Thanks for your interest in this matter. As I said in an earlier post, the chase is well insulated from the roof deck down to the ceiling and where it penetrates the ceiling it is well sealed and insulated.
I'm curious, are you a builder, installer or...? You say you have seen this several times; has the situation been remedied in any of the houses you've see and if so how? Thanks.
Bob
ventilating the chase works well to fix this problem but it is not the best as far as energy efficency
maple1
Minister of Fire
Having a hard time visualizing this one.
Is the chase only in the attic? (The 4' between ceiling & roof?)
Is the chase only in the attic? (The 4' between ceiling & roof?)
But from the roof deck up its uninsulated, correct?Webby,
Thanks for your interest in this matter. As I said in an earlier post, the chase is well insulated from the roof deck down to the ceiling and where it penetrates the ceiling it is well sealed and insulated.
I'm curious, are you a builder, installer or...? You say you have seen this several times; has the situation been remedied in any of the houses you've see and if so how? Thanks.
Bob
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