Frost around collar-the thaw

[SammyBwood]

In Northern Wisconsin. We get a lot of subzero temps and the collar where our pipe exits the house gets frosted up.
We have a Vermont Casting Encore in the basement, outside corner of the house. It vents horizontally thru a studded wall (below is a concrete knee wall) to a chase. This is a new build (now 4 yrs old) and I was willing to sacrifice space upstairs to vent it straight up, but our builder and the fireplace installer determined this set up was best. I'm no expert which is why I'm asking the question...We get a lot of frost around the collar in subzero temps. Of course that thaws and I can see drips forming at the edge of the square trim piece. I keep a towel on the ledge at the top of the knee wall so it doesn't pool up, but I can't help but worry what is going on inside the wall. I've asked around but can't get any good answers and am often told "it's the nature of the beast".

Is it an install issue? Can something be done to fix this? Or do we have to put up with it? I try to use the fireplace as much as possible to keep the frost from forming, but there are times we just can't. Our humidity in the house is at 45% and until this winter, we haven't had to run the dehumidifier since building in 2018.

 

[begreen]

Your installer was incorrect, you were absolutely right.

Can you post a picture of two of the outdoor side including details of sealing?

 

[armanidog]

There must be a hole letting in cold air around the pipe. Roxul insulation may work if you can put it around the pipe inside the wall.

 

[SammyBwood]

Your installer was incorrect, you were absolutely right.

Can you post a picture of two of the outdoor side including details of sealing?

Thank you - just added 3 photos from the outside to my original posting.

 

[begreen]

Looks like you have a little snow there.
What are we looking at? Is the outside view of the house before the chimney was installed? I see a chase on the corner, but no chimney pipe going into it.

The looking-up view looks close at the top. Is there 2" clearance all the way up?

 

[SammyBwood]

Looks like you have a little snow there.
What are we looking at? Is the outside view of the house before the chimney was installed? I see a chase on the corner, but no chimney pipe going into it.

The looking-up view looks close at the top. Is there 2" clearance all the way up?

The full outside view is of the chase, believe it or not. It's sided with vinyl siding and starts a couple feet from the ground. I was able to take a photo from the bottom of the chimney and tried to get as close to the tee where it goes into the house.

 

[begreen]

Got it. Is there 2" clearance all the way up for the chimney pipe?

Is the bottom of the chase open? If so, I would be inclined to extend it another 2" and add a removable bottom cap.

It's hard to believe how the installer insisted this was a better way to install. It cost a lot more, looks tacked on, and has left you with issues that shouldn't have happened.

 

[SammyBwood]

Got it. Is there 2" clearance all the way up for the chimney pipe?

Is the bottom of the chase open? If so, I would be inclined to extend it another 2" and add a removable bottom cap.

It's hard to believe how the installer insisted this was a better way to install. It cost a lot more, looks tacked on, and has left you with issues that shouldn't have happened.

Yes - definitely 2" space around the chimney pipe all the way up. Yes, the bottom is open. Would that help to seal that off? That's easy enough to build. I'm not impressed with the company we purchased the stove from and their install. I reached out to them a few different times and left messages. I tried again today and actually spoke to someone. He said he'd call me back after he talks to the installer. The guy we dealt with is no longer working there.
I've seen houses with an exposed chimney pipe all the way up the outside of a building...surely that would have the same issue, wouldn't it?

 

[begreen]

Yes - definitely 2" space around the chimney pipe all the way up. Yes, the bottom is open. Would that help to seal that off? That's easy enough to build. I'm not impressed with the company we purchased the stove from and their install. I reached out to them a few different times and left messages. I tried again today and actually spoke to someone. He said he'd call me back after he talks to the installer. The guy we dealt with is no longer working there.
I've seen houses with an exposed chimney pipe all the way up the outside of a building...surely that would have the same issue, wouldn't it?

Yes, sometimes they do have the same issue. Did they apply a bead of silicone around the flange before installing the chimney pipe? Did they seal the gaps around the pipe with silicone?

If the chase is reasonably tight then sealing the bottom (with the required clearance) may help surround the chimney pipe and Tee with a warmer envelope.

 

[SammyBwood]

Yes, sometimes they do have the same issue. Did they apply a bead of silicone around the flange before installing the chimney pipe? Did they seal the gaps around the pipe with silicone?

If the chase is reasonably tight then sealing the bottom (with the required clearance) may help surround the chimney pipe and Tee with a warmer envelope.

I did not watch them install the fireplace and chimney. At least I'm feeling that my concerns are valid and I have a leg to stand on. I won't be so apt to let them tell me it's "to be expected". Hoping they call me back as promised so I don't have hunt them down again. Thanks!!