Will I create Ice Dams?

So, I had some ice dams a couple of weeks ago on the north side of my house (this is also where my internal chase penetrates my roof). Not too bad, just enough to drip through soffet vent strip, not inside walls. A combination of two things caused this:

1. A really cold snowy winter (for my house)
2. Having my fireplace chase (which is internal and goes through my attic) allow hot air into my attic during a few days of construction to frame the opening for my new install.

So my question is, although my attic is normally very cold and well vented, will the 2 or 3 feet of Class A pipe that is going to extend through my attic create ice dam issues in the future?

It seems to me that burning my fireplace may add as much heat (or more) to the attic as having an opening to the heated space below over a weekend that caused my recent ice dams.

How hot does the exterior of Class A pipe get??

The attic floor will be about 14 feet above the top of my Lennox Brentwood when installed.

Thoughts?

Thanks,
Pete

Having the chase open did make the dams worse in my case. It was 10 F outside, but my attic was getting heat from me working on my chase. Water soaked through the plywood - only the bottom six inches of the roof line (I could see this from the chase opening). I do not have gutters on the back of the house anyway, but still had the dam occurring on the soffit portion of the roof, and worse towards the end where my chase was open for about 48 hours. The overhang is about 1 foot, so no water got inside the walls, but rather formed icicles through my soffit vent.

Within a few hours of sealing the chase - no more drips.

I do agree I have seen more icicles this year on peoples houses in eastern MA than in the last 10 combined, so I am not too worried about it. I do not have icicles on the back now, since I sealed the chase temporarily with plywood to keep the attic cold.

I am a little concerned that the Class A will heat the attic (locally) to some extent. I guess I will just have to watch it and do snow removal as needed - this will keep the area available for sweeping also.

The calcium chloride in a stocking (from another thread) sounds like a good idea for controlling the dams, also.

Like someone else said, short of building a chase in the attic around my Class A, I do not see how else I could insulate the Class A from the rest of the attic. I have a lofted ceiling next to the area of the chase, though, so I do not have access to the attic in this area, aside from inside the chase on the second floor currently exposed.

Pete

LLigetfa said:

I ran radiation shield all the way from the firestop at the ceiling to the flashing on the roof. It serves to hold the heat in so the chimney drafts better and stays cleaner.

Click to expand...

Actually, missed this the first time - sounds reasonable. Just sheet metal, right?

My wooden chase extends above the roof, so the heat will have room to rise locally above the roof level. I was also wondering if I could vent the chase somehow...this is the old setup.