Ice Damming on the roof

I don't have a insulation problem because I never had this problem before getting this stove but the roof above my cathedral ceiling is starting to ice dam up. I can't add insulation because of access to it with out major construction. My only other thought is the heat tape wire for roofs.

Just thought I asked if anyone else noticed this on their house since getting a stove?
thanks
md

Thanks Reggie,

I was using a ZC fireplace for 10 years and was not getting the heat that my new Avalon insert produces. For 10 years I had no problem with ice damming on the north side only of my cathedral ceiling, the south side is fine.

I do have a ceiling fan up there, I have not use it every day because when the stove has been going the heat will travel to the upstairs into the bed rooms.

I was involved with some of the construction of this house and we over insulated it can't remember the exact r-value but with the windows, skylight and Cad- ceiling it was definitely the right r-value.

My problem is I am adding a lot more heat in this room...and loving it. The stove is at 500-D in this room. Last year I noticed a start of it but the snow was not as much as this year has been already.

I did read some old post they tend to go off in a different directions of my question so my question is when you can't add insulation like in a attic are there any other options other then elect heat tape or a major ceiling re-model ?

thanks again for any input...
md

[quote author="RPK1" date="1292046661"]Does the cathedral ceiling have continuous soffit and ridge vent? If so, do you know if there is an air space in each rafter bay next to the roof sheathing? Usually this air space is created by installing proper vents or styrofoam shutes the whole length of the rafter before the insulation gets installed. yes there is a ridge vent and styrofoam in between each rafter I have plenty of air space between the ceiling and the roof, I would say about a foot if I remember right when they installed the insulation.


Are there any recessed light fixtures in the ceiling? If these are not sealed properly they will vent the warm moist air into and through the insulation and cause a condensation problem. yes there are I thought about that but they are new construction recessed lights where the insulation is over it or can touch it so it has insulation over the fixture in the ceiling if that makes any sense making a vapor b.


If at all possible try to carefully lift a tab of shingle up near the ice dam problem. Look at the roofing nail head. If the nail head is rusty there is most likely a condensation problem. That usually means the nails are rusting from the underside out do to a condensation problem in the roof system. Have to wait on this till the ice is gone...thanks for that tip.


I have been in attics in the winter where the underside of the plywood sheathing is full of mold and icicles are hanging off the ends of the roofing nails. This is caused by a combination of poor vapor barrier installation and lack of ventilation. I'm pretty sure I don't have this because the builder was very adamant that there was circulation I was the one asking why the space was not filled to the roof with insulation he explained the ventilation,mold, two air spaces. ridge vent system to me.


If there is any way you can direct that high temperature air out of the cathedral ceiling area you may be able to save the ceiling. This is my thought too...going to start to use the ceiling fan more I just remember that in my attic where the cathedral ceiling starts there is a complete wall to the roof blocking it off maybe I can cut into that wall to get just under the roof and add some blown in insulation in there. I'm not sure, will have to get up there and take a look maybe call a company in to make sure but the last thing I want is mold problems because there is no circulation, after that.

RPK1...thanks for your help you got me thinking there could be a way.
md

Thanks for the replies, great link, will be looking into them.

We are having a 40 degree day so getting some melting right now. Will try tomorrow for pictures.

I'm thinking no matter what I do, (in my case) even adding insulation might not be the answer. There is just a blanket of snow on the roof. There are no bare spots of melting snow on my roof like you see when there is a lack of insulation. I just think when I get that stove cranking the heat will naturally go up there and warm it. So I'm thinking the heat tape may be my only fix.

If it all melts I can start over next week with the forecast and this time use my fan to move the air in the cathedral ceiling...see if that changes things .
md

RPK1 said:

md, send out some pictures if possible

RPK1

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RPK1,
this is a picture of the roof the wall on the right when in the attic my thought was to get under the roof line to add but I'm think that may be difficult. Roof faces North side
md

RPK1 said:

md, send out some pictures if possible

RPK1

Click to expand...

this is a picture of the inside looking out picture not that good but you can see the skylight and recess lights and fan.
md

shawneyboy said:

It may be more than that, notice the snow melt off the right side, higher roofline. I think there may be something else, contributing to the situation. There seems to be more heat loss than just the chim and skylight. Can we get another pic of the entire roof (both sections) ? In the other section is there an attic space?

Click to expand...

This is a long post just a reminder ...I have had no problems with ice damming till I got the Avalon last year.

One problem thats not helping you is we have had a couple of 40 degree days plus rain this morning. Prior to that my roof (all of it) was cover in snow not showing any heat lost just the ice dam on the north side Cathedral ceiling only. Here is a picture of the top roof. the picture on the right is over the garage Thanks again for your time.

Edit: I think maybe my problem maybe the top roof draining to the cathedral roof added more water to that cold roof like in the picture on the left. Which could mean I could use more insulation in the attic not the catherdtal roof. What stump me was my whole roof was covered with snow not showing any heat lost.

Here is a picture on the cathedral roof on the SOUTH side, inside ceiling has the same skylights and recess lights. Notice no ice damming even with the rain melting. All gutters are clear and draining right now.
thanks
md

Edit; on this side I don't have the top roof draining to this roof so I don't have the ice problem here on the south side like in the picture above. May have figured this out just by watching the rain today.

pen said:

Perhaps all you need is heating in your gutters? I have melt off as a result of my bathroom vent / chimneys and my icing problem comes from large eves which allow the water too cool a lot before hitting the gutter. Maybe some heat tape in them would be all you need? If you try it, I recommend the doubled over installation instructions.

pen

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Yes, I will ...probably add the tape to the gutter after this snow storm...also I think they (Washington leaders) may extend the tax credit in 2011 so I will add insulation then too for the tax credit.

I have to thank everyone that replied kept me thinking also watching the rain show the path of the ice dam.
thanks and will update after this snow or when it warms up a little...10 degrees today outside 70 degrees inside.
md