Ice dam help


Old 09-20-18, 12:21 PM
Thread Starter
Join Date: Jan 2018
Posts: 503
Received 0 Votes on 0 Posts
Ice dam help

Back again. Figured I would try and solve my ice dam issue now Before it gets colder.
Iíve edited some of the previous pics to show the existing heating cables in red and the flow of water in blue from the valleys in the centre of the roof towards the front of the roof. Hoping to give you a sense of the roof design.

Thereís also a small prow roof section right above where the ice buildup forms and I noticed during a rainstorm that water is coming off the prow and falling onto to the shingles below right where the ice buildup would be.

1. Do the heat cables belong where they are now? Iím wondering if they may be contributing to the advanced melt and causing the dam to be worse
2. Should I concentrate the heat cables in the area of the dam and also run the cable down the downspout?
3. Any other ideas? Should the prow roof have gutters on them?
4. Could I install a gutter in the green area to capture water running from the valley and off the shingles?

The problem exists on the other side of the front door but to a lesser extent. The area Iím mostly talking about is mostly over an up heated garage but the close to the heated entrance foyer. Problem areas circled in yellow.
Attached Images      
Old 09-20-18, 01:03 PM
Marq1's Avatar
Join Date: Sep 2016
Location: USA MI
Posts: 7,139
Received 462 Votes on 430 Posts
I vaguely recall this post last year but I will give what I probably did last year.

Ice damns are a heat loss issue, if you want to resolve you should address the root cause rather than the band aid!
Old 09-20-18, 04:09 PM
Thread Starter
Join Date: Jan 2018
Posts: 503
Received 0 Votes on 0 Posts
I’m not convinced this is a result of traditional heat loss. Insulation was upgraded to R50 a few years back. Ridge vents run along the top for venting. Is it possible the flat valley (with its black covering) is Causing excessive melting. It’s a new home to us, and there isn’t any damming elesehwere other than the two sports in yellow. Could it be just because if the excessive flow there. The area marked in green sees a tonne of water coming off it when it rains.

It only dams in this one spot where a large portion of the roof drains. You can see in the top middle photo........all the snow and rain from those 3 roof edges; flows down into the area where the dam is shown in pic 4. The dammed area never gets any sun based on roof design.

The heating cables were laid by the previous owner (shown in red) Maybe there the things that are actually causing the melt. Why lay cables above a heated area?
Old 11-05-18, 12:37 PM
Member In Good Standing
Join Date: Jan 2008
Location: usa
Posts: 159
Received 0 Votes on 0 Posts
Is this still an issue?

Not sure this is still an issue? For those us us who do not follow your posts of a year ago what is your specific issue?
I agree you can get snow melt on a roof without an insulation problem. If it is melting and not making it to your gutters before it refreezes and building up you may have a problem. You need to heat the run off area to keep it as water until it hits the downspouts. I would add heat tape in the valleys and in the gutters to be sure it drains off before freezing. I had a similar problem and needed heated gutter covers and heat in the gutters and the downspouts. This solved my problems. I removed the heat from the roof itself and let the snow build up. I was not getting heat loss through the roof. I was getting solar melt. Once the snow built up I no longer got the snow melt below snow at the roof and this no ice dams. But I needed to keep the gutters snow and ice free for when the snow melted.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: