With the big storm we are now having here in the Northeast, we may well be having the best conditions for the formation of ice dams that we’ve had in over 10 years. Classic ice dams form under deep, fluffy snow with bitterly cold temperatures outside, and that’s what we have now and the forecast is for below-freezing temperatures all week.
Next summer, we can talk about ice and water membranes, ventilation, insulation and sealing air leaks into attics. For now, about the only thing that can be done is to try to get the snow off the roof. Ten years ago, I was young and dumb enough to get up on a ladder and shovel snow off roofs and chop channels through the ice to release a cascade of water. This time, I’d only do that for VERY good customers.
I hope others will post their ice dam storys here as things develop this week.
Al Mollitor, Sharon MA
Replies
For 1-story homes, and some two-story homes with steeper pitches, you can use a roof rake to remove the snow while standing on the ground. Basically a long sectional pole with a piece of sheet metal about 2 feet by 8 inches, bent into an open U (bends parallel to the long edge) to make a sort of scoop or or double-sided shovel.
If you can keep the bulk of the snow off within about 4 feet of the exterior wall edge then ice dams aren't too likely to form (except on home with major problems).
Up in Minneapolis I understand that a number of outfits use steam cleaners to melt the ice, after removing the bulk of the snow. I've also heard of folks having something on the order of a long, narrow sandbag with hoses running back and forth through it. This is layed on the ice dam and hot water run through the hoses.
Mojoman,
For many years we suffered with the problems arising from ice dams, and last July we finally fixed it. Permanently (unless the place burns down).
Why did we allow it to go on so long? Well, in the first place, I was younger. Sound familiar? I was always willing to do things the hard way, rather than pay for the right way. In the second place the technology wasn't available.
Our 200 year old, braced post and beam framed house has been the root problem. What appeared to be the soffit and facia in the eaves was, in reality, the visible parts of a timber twelve inches high and twenty four inches wide, running the entire length of the eave. No matter what we did (and we did a lot) it was just about impossible to get ventillation under the edge of the roof. Therefore, ice dams every January. But not this January.
After a great deal of research and talking to MANY contractors (most of whom admitted they didn't have the foggiest idea what I wanted), I had an experienced contractor install a Hunter CoolVent roof. The contractor himself never showed up on the site and I have yet to meet him face to face, but never mind, it came out VERY well. His extremely professional seven man crew showed up in the morning, tented the entire house to protect the siding and plantings, tore off the old shingles, screwed the CoolVent panels on the old roof deck, and then put a conventional high quality shingle roof over it. At 7:30 that same evening they pulled out of the site, having finished the job and scrupulously cleaned up, including a careful manual touchup with 409 and a rag wherever small marks were made to the siding. The next morning the dumpster was picked up and there was no sign there had been a project here at all. I would have liked to meet the boss, if only to shake his hand and thank him in person, but I'm grinnin'! It was the best experience I ever had with a contractor.
And today, January 23, 2005, under a monsterous and frigid snow storm, we have no icing. Really! NONE!
Log house builders have been using the idea, but not the prefabbed panels, for years, and they call it "cold roof". They fasten extruded polystyrene panels to the roof deck, then spacers for the air space, and the nailing surface on top of that. I couldn't find anybody to consider that approach for less than $14k. My new roof cost me less than $6k.
Hope this provides the seed of a good idea.
Best regards,
Don
Don,Just out of curiosity...How many square of roofing did seven guys tear off and replace in one day for $6,000???Thanks.
Rich BeckmanAnother day, another tool.
Rich,
It was about 13 squares.
Don
Don, curious what part of the country you live in. Also would appreciate any more info you can give me on these cool vent panels
Thanks,
Shoe
Shoe,
I live in NW Pennsylvania, half way between Cleveland and (the notorious) Buffalo. We get almost as much snow as Buffalo, but not quite.
Here's a link to Hunter's PDF document on Cool Vent:
http://www.hpanels.com/pages/pdfs/CoolVent_3.pdf
Do yourself a favor, though. Don't try to get any specific questions answered. They don't respond to such queries.
Good product in the hands of capable contractors, lousy attitude about response to potential endusers.
Regards,
Don
Thanks for the link. I'll have to look into it further when I have a little more time.
I assume they installed some sort of vented drip edge or something and a ridge vent - is this right?
Absolutely right, they fabricated a custom drip edge that hangs down in front of the panels and allows air to pass beneath.
They also used a new ridge vent that has a rigid plastic frame and filter mesh over that. It's all working well.
Don
I use a snow rake on a preventive basis when possible. This storm it was possible. We have a 30" snow belt around the eaves, water/ice shield underneath that, and a second width of it above the snow belt. If that doesn't work I use a rubber mallet to break the ice up from the snow belt. It's an old house, and one of the things I was most excited about was the pair of open windows in the gable ends of the attic. I figured they'd be enough to keep the roof cool enough to keep ice dams from happening, but alas, despite many efforts, and some suggestions from BT, that's not the case.
true snowraking story from today:
Put on my snow pants, jacket, and snowshoes because it was pretty deep and went to work. Got over to a section, pulled off a bit, then got a little closer and reached as high up the roof as I could. The rake hit, and I started to pull. I looked up and was able to discern a crack in the snow appearing near the ridge, and thought that a little odd, but let it pass and continued to work the snowrake down through the snow. When I felt the rake hit the shingles, I noted that the crack appeared to be growing. The first chunk of soft snow hit the ground with a light thud, and then a second followed and it became apparent that more snow than the width of the snow rake was going to be coming down. Apparently the coefficient of friction between the shingles and the snow was being overcome by the force of gravity, aggravated by my working the snow rake around.
Doing my best to resolve the number of cubic feet of snow, their approximate weight, the length of the roof, the distance to the eaves,
the force of gravity, reduced by effects of angular momentum (it's a 10/12 pitch), I quickly determined it would be in my best interests to take a step or two back.
But, the beavertail snowshoes I had on decided, as they always do, that backing up, particularly in 2ft of snow, was not what they wanted to do. It was at this point that the little crack in the snow near the ridge opened up menacingly, as if to swallow me up.
And then it all came down in a rush, much of it catching me in my stomach and knocked me to the ground, buried me up to my chest, and I could not stop laughing. It took a few minutes to get the snowshoes, snow rake and myself unburied, at which point DW comes out to see how things are going. "What's so funny? Why are you all covered in snow?"
Great story. Thanks for sharing! I always wondered what you guys in NH do for fun!
Al Mollitor, Sharon MA
The cure: isolated soffit to ridge vents. Taught myself this after the BIG eastern snow storms of 93.
Your right: extremely low temps and deep snow providing lots of external roof insulation. The perfiect storm for ice dams and water comin' out of everything in the house.
Ok, you didn't ask for the details, but let me offer for those with the water-comin-out-of-my-walls problems this year as a fix they can tackle this summer.
Rip 1X2's and tack in where the back of the roof deck meets the rafter. Cut 1/2" rigid insualtion the width of the rafter bay (either 14.5 or 22.5 inches) and push up against the stops you just installed, and tack in place. This will form the chute from the soffit all the way up to the ridge vent.
Puts fiberglas batts in behind this, and make sure gable ends have some sort of open venting.
From 93 until we left to come back to Oregon (2000), you could tell our roof was different in our neighborhood....snow never melted...proof the ventillation system was working....and with my newly finished attick space (an extra bedroom for our then teenager), it was nice and warm up there to boot!!!
BruceM