Ice damn in gutters due to chimney heat?

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Cate68

Cate68

Member
Dec 7, 2010
233
Akron, OH
Hi all,

I have a question I hope someone knows something about. We've had our first blast of cold air since I put in my insert, and I noticed that with the snow, my gutters are now jammed with ice on the same side of the house as the fireplace. The house is one story with an unfinished attic that is fully insulated and vented. I'm wondering if the chimney is getting warm enough to heat the attic melting the snow causing the ice damn. If so, how do I stop it? The chimney is brick masonry with a 6" liner and if I recall correctly, the brick is exposed in the attic. I never had this ice problem with the old open fireplace and I'm getting worried I may have a big repair bill if I can't figure this out. Thanks for any advice!
 
I'd guess that over the stove is the hottest part of your ceiling and your just losing more heat there than elsewhere.
It happens here too.
 
The chimney should not be heating up the attic that much as long as the attic has proper ventilation. What type of attic ventalation do you have? Could the insulation be blocking the ridge vents ?
 
Thanks for the replys!

Kenny – You get ice damns too? Have you had any roofing issues because of it?

Shawneyboy – The ventilation is all attic vents. The house doesn’t have ridge vents, but I will have them put in when the roof is replaced. Do you think this could be the problem?
 
Cate said:
Thanks for the replys!

Kenny – You get ice damns too? Have you had any roofing issues because of it?

?
Click to expand...




It's a low and fairly flat roof so I use a snow rake when we get a lot of snow.
What I need are soffit vents to carry escaping heat up to the roof vents but the jerk who built this addition left no room.
 
Well, I'd best stay off the roof - I'd break my neck for sure. Looks like I need to do some research to determine the best route to eliminate the problem.
 
Cate said:
Thanks for the replys!

Kenny – You get ice damns too? Have you had any roofing issues because of it?

Shawneyboy – The ventilation is all attic vents. The house doesn’t have ridge vents, but I will have them put in when the roof is replaced. Do you think this could be the problem?
Click to expand...

I am NOT a roofer, but am related to one. Ice dams are caused by usually snow, melting, running into gutters, and refreazing. If you have a properly insulated and properly ventalated attic space, this should not be happening. It is to my understanding that using a soffit and ridge vent system is the best way to have proper ventalation in an attic. Again I am NOT a roofer but I would be surprised if you don't get a response from a roofer on the forum. There has to be one.

I would think that it is either one or the other, or a combination of the two poor ventalation and/or poor insulation.

When you said you have, attic vents, are they the roof top, stainless steele type, or the slated vents on either end of the building (old style).

Also just curious, how large is the overhang, beyond the side of the wall, to the roof edge, just to get an idea. If you can post some pics of roof/ gutter edge (from ground level).
 
I know there is a lot of insulation up there, so heat escaping into the attic should be minimal. The attic vents are both roof top and slated, but the roof top vents are only on the back part of the house - it's a Cape with an addition off the back. The attic is all open between the house and addition. There is also a window I could look into figuring a way to open without filling the attic with rain and snow. The overhang is rather small, not sure the size, but I'm sure there is no soffit. I will double check when I get home. This is great info, thanks so much! And I do hope a roofer chimes in...
 
Is the fireplace and chimney for the most part all inside the house and attic? Or is it totally on the exterior of the house? You may have a fair amount of insulation in the attic but the heated air must be leaking into the attic space by way of a draft leak around the top of the fireplace near the ceiling or maybe a light fixture or some other penetration through the ceiling. Some pictures may help a little.

RPK
 
I installed a this in my gutter. My masonry chimney absorbs heat if it's a sunny day and would cause melting around it whether I was burning or not.

013627109704lg.jpg

pen
 
The chimney is on the outside of the house, but if I recall properly, in the attic you can see the brick. There is a light fixture I can check - thanks for suggesting that. I'll try to get some pictures. Still, with all this great advice, I still can't figure out why the ice is damming up only on the south side of the house where the chimney is. You would think there would be icicles all around the house, or at least also in the front since the fireplace is in the living room, which has outside walls on the west, south and east. Odd.
 
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south side gets the most sun.

pen
 
Pen - True, but we've had no sun...just 3 days straight of nothing but lake effect snow.

Rudyjr - That's a very good question. I'll have to call the company that installed the insert to find out about the block off plate. Thanks!
 
Cate, Since I installed mine I have helped install three other inserts for friends I have done this on all of them. I have not had one issue with ice dams or poor performance on any of them. I would have never known to do this when I installed my stove if not for the fine folks on this site.No dealer or sweeps in our area ever mentioned this to any of us when checking into stoves. I think this is the most overlooked item to improve performance and it is not done because people (installers) don't want to take the time to do it.
 
One thing that is for sure ....... You have a enough warm air either escaping from the interior of the heated room or radiating off the chimney in the attic (or a little of both). This is mixing with the extreme cold dry air and creating condensation. Know that warm air carries a lot of moisture. When this area cools down it freezes. Usually outside in a gutter. This is an ice dam. If it was never cold enough to freeze you would only have condensation in the attic area and sooner than later a mold problem will follow. I think you need to find where this heat loss is occurring and seal it up or insulate it somehow. You could try not running the stove for a few days and see if it clears up. That will narrow it down a little.

RPK
 
shawneyboy said:
I am NOT a roofer, but am related to one. Ice dams are caused by usually snow, melting, running into gutters, and refreazing. If you have a properly insulated and properly ventalated attic space, this should not be happening. It is to my understanding that using a soffit and ridge vent system is the best way to have proper ventalation in an attic. Again I am NOT a roofer but I would be surprised if you don't get a response from a roofer on the forum. There has to be one.

I would think that it is either one or the other, or a combination of the two poor ventalation and/or poor insulation.
Click to expand...

+1 A good friend of mine is a roofer, and he's told me the same thing. He told me that when he's out driving he reflexively notes which houses have melted area on the roof, and points out the poor configuration. He said it got to the point that his young children would do the same.

The attic is "unconditioned space" and, through proper insulation and ventilation should nearly the same temp as the outside, so snow doesn't melt. People have already mentioned ventilation, but I also suggest beefing up your insulation, both on the chimney inside the attic, and on the attic floor. That will help keep heat in your house too.

HTH, and good luck!
 
Try to get us some pics of the attic if possible. There are wrong ways to over-insulate as well as under-insulate an unheated attic space.

RPK
 
Cate said:
Hi all,

I never had this ice problem with the old open fireplace and I'm getting worried I may have a big repair bill if I can't figure this out. Thanks for any advice!
Click to expand...


This part of Cate's quote says alot. What has changed since last year is the stove install if I read this correctly.
 
Rudyjr said:
Cate said:
Hi all,

I never had this ice problem with the old open fireplace and I'm getting worried I may have a big repair bill if I can't figure this out. Thanks for any advice!
Click to expand...


This part of Cate's quote says alot. What has changed since last year is the stove install if I read this correctly.
Click to expand...

Agreed, the stove has changed the situation, but the solution is most likely not to go back to an open fireplace. The stove may be enhancing a situation that already existed. There are times when changing one thing has an effect on something else, lets say you install a stove and now you notice the drafty windows because the draw from the stove has enhanced the situation. Then the issue is not the stove but is the window.

I am assuming that by adding the stove it has enhanced something. The chimney should not be making this much of a difference to the home/attic where ice dams are now happening, but it may be exposing the lack of proper ventalation, or proper insulation because the home is now warmer, or the minor increase in temps in the home, or something else.
 
I used to have more of a problem with ice dams . . . insulating the knee walls in the Cape helped a lot . . . however there is still a section on the eaves that freezes . . . now I just make a habit of getting out the roof rake to clear the snow after I finish plowing the driveway and clearing the decks.
 
Good heavens, I just noticed my typo in the topic name...sorry about that! I mean, it does make me want to swear, but how embarrassing! :)

Rudyjr - where did you get your block off plate - a fireplace store or somewhere like Lowes? Is that something I can install myself?

Thanks RenovationGeorge - is there a special insulation I could use for insulating the brick chimney inside the attic? I don't have, and never have had, any melt spots on the roof, so at least that's a good sign.

RPK1 - I'll definitely get pictures, probably this weekend since it's dark when I get home.

FirefighterJake - Where is the knee wall? I had insulation blown into the walls before the siding went on and have R19 (or higher, I think) in the attic over top of the old insulation...is there somewhere I've missed?

Thanks again everyone, you are just wonderful. From what I'm gathering it sounds like I have a ventilation problem since the roof is lacking a ridge vent. I'll post picture soon...
 
Cate, I have fabricated the ones that I have installed from ordinary pan material from an HVAC supplier, but I believe that you can get the same thing from the big box stores. There are instructions on this site if you do a search I believe BeGreen has posted some instructions somewhere. Please don't think that I am stating that you should go back to open fireplace to resolve this as was stated by a previous poster. What I was saying is that more than likely you are now using your insert to heat your house "AND" the entire mass surrounding it. You are heating all of the masonry the firebox, the throat of the fireplace. and the chimney between the old liner and the flex liner. With an open fireplace you are sending massive amounts of air up the chimney along with the smoke from combustion. A masonry fireplace stays relatively cool in an unheated space when burning a fire in an open fireplace.
Cate, here is the link for the block off plate instructions, https://www.hearth.com/econtent/index.php/articles/making_a_block_off_plate/
 
Rudyjr - Understood. And thanks for that link...that's a nice looking block-off plate. I'm 99% sure I don't have one of those, which means the only thing closing the house off from the openness of the masonry chimney is the surround finishing off the insert. Grief - so many things to worry about!
 
Cate, Some installers and sweeps I have talked to in our area say that they pack insulation in the damper area to block off heat transmission when installing inserts. I have no first hand knowledge of how this will work but I know you can probably do it by just removing the surround. I believe that this might be something you could do in the interim to help. On the inserts that I have installed we have put rock wool fire stop insulation in the damper area around the liner before we put the block off plate in and around the top under the cap.
 
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