Preventing Icicles

Reply

  #1  
Old 01-03-13, 05:18 PM
Member
Thread Starter
Join Date: May 2007
Location: New York
Posts: 196
Received 0 Votes on 0 Posts
Preventing Icicles

I have a porch that extends off of the front of my house. There is a short ~10 ft gutter over this porch. I have an ice build-up in the gutter that has built up so much that the ice has forced its way into the inside of my porch. Other than the gutter, the rest of the roof looks snow covered the way it should. How likely is it that, if I put the low voltage heating wire (ice melter) into the gutter and down into the down spout, the ice will prevent the ice from building up to the point that it overflows the gutter? I have attached some pictures.

Thanks
 
Attached Images  
Sponsored Links
  #2  
Old 01-03-13, 05:41 PM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,483
Received 33 Votes on 30 Posts
Hi Joe,
Unfortunately you would be treating the symptom and not the cause. The snow you see above the ice can be acting like an insulator and helping a source of heat (to be determined) melt the bottom layer of snow which runs down to where it get exposed and builds up an Ice dam. First step, keep the snow cleared.

Second would be to locate the source of the water. is it from the porch or from the roof above? From the porch would be strange as the ceiling of the porch is probably not heated, or is it?

Is the source possible from that leader leaking near the bottom. Often they will freeze solid and spill water down the sides.

Last will be locating the heat source, but that process starts once you locate the origin of the water.

Bud
 
  #3  
Old 01-03-13, 05:46 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,879
Received 299 Votes on 272 Posts
Its unlikely it will prevent ice dams, like what you have, but it certainly won't hurt. The benefit of having a wire in the gutter is that it will allow "some" drainage to take place, which is better than NO drainage when it's completely blocked with ice. Usually you want some of the heating wire to snake up and down (like a wave) on the shingles above the gutter to keep the ice from damming, which is usually what causes roof leaks in the wintertime. (on warm days when the snow above the ice dam melts, the runoff pools up and backs up under the shingles because it can't easily run off).
 
  #4  
Old 01-03-13, 08:05 PM
Member
Thread Starter
Join Date: May 2007
Location: New York
Posts: 196
Received 0 Votes on 0 Posts
Name:  DSCF5899.jpg
Views: 888
Size:  24.8 KBName:  DSCF5900.jpg
Views: 1022
Size:  28.9 KBThanks for the info. The upper roof where the leader comes from has been completely insulated and baffles inserted. So, that leader really shouldn't be adding water. The area above the porch is partially open to an area above a cathedral ceiling and the other side is a bedroom wall. I had that entire area above the porch insulated w/ spray foam, DOW board and fibreglass insulation. Now, it is not feasible for me to re-insulate the entire house because of the lack of accessible attic space. So, is there any other solution that you can think of that would prevent the build up of ice? Would running the wire on the roof, then into the gutter and on down the downspout prevent the ice back up?
 

Last edited by joeponcho; 01-03-13 at 08:19 PM. Reason: To add photo
  #5  
Old 01-03-13, 09:22 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 23,879
Received 299 Votes on 272 Posts
If get on a ladder and scrape the snow away, you will get a good idea of where the problem areas are. If the entire roof has a layer of thick ice on it... well you have a lot of warm air getting out there causing the melting. I'm betting its just the last couple feet. At any rate, running the wire on the roof (back and forth in the areas where you have the most ice buildup) and into the gutter will "help".

I would never be so bold as to say, "Yes, this will prevent ice dams."

If the porch roof is "partially open" to another attic space, that is likely where the heat is coming from that is melting the snow. You want the porch roof to be COLD.
 
  #6  
Old 01-03-13, 11:31 PM
Member
Join Date: Oct 2008
Location: New England
Posts: 10,483
Received 33 Votes on 30 Posts
As X said, the heat wires will help and I understand, especially this time of the year, that construction isn't always possible. But now is the time to be troubleshooting. Next spring it will look fine.

A couple of thoughts.

Is there an attic space above the porch roof that could be gaining heat from the ceiling/walls inside the house?

There are under shingle vents that could be installed at some time (like when a new roof goes on) to vent isolated spaces.

Or a layer of rigid insulation could be added to the roof, below the shingles, to insulate from the top.

Is there a ridge vent at the top of the slope above the shingles?

Just as an example, look ar these GAF vents: GAF | Cobra FasciaFlow Vent (Attic Intake Vent)

If the melt is coming from the area just above the ice we see, then removing the snow every time mother nature deposits it, will prevent the ice. Note, as X suggested, where the ice underneath starts and stops. Above the ice dam it will typically be a thin layer as it has been insulated by the snow. Be careful as removing just the bottom few feet of snow can allow another dam to form where melt from above exits the snow layer and freezes at the new cleared space. Clear it all the way up so it no longer acts as an insulator.

I have an ice problem/solution in progress and just shoveled the last storm to identify the couple of remaining areas that need attention.

Bud
 
  #7  
Old 01-04-13, 06:06 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 21,558
Received 315 Votes on 289 Posts
I've seen the thawing wires used quite a lot in Park City, UT on newly constructed high end homes so I'm thinking there are some conditions even with proper roof insulation where ice daming is a problem. On those houses they had the heat wire in the gutters & downspouts as well as zig zagged on the roof about a foot up from the gutters to prevent ice daming over the eaves.
 
  #8  
Old 01-04-13, 06:15 AM
Member
Join Date: Jan 2012
Location: Canada
Posts: 2,739
Received 16 Votes on 15 Posts
I suspect that you are dealing with snow melting from either heat loss from the house (leaking into the porch covering or from else where). The water will follow the path to the lowest point.

I was in a similar situation at my previous house, and used heating wire on a timer. I ran it similar to how XSleeper had mentioned and set the timer to run a couple hours a day, during the warmest part of the day (Noon to ~3PM). This way, you have the heat of the noon sun helping your wiring and not forgetting to turn it on, or leaving it on for days straight.

Going forward, you'll need to figure out where the water is coming from (and/or how it's being produced. As others have mentioned, it could be heat from inside, warming the roof.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


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