Posts Tagged ‘icicles on roof’

What can you do about Ice Dams and Roof Damage?

January 17, 2014

iceEven though we’ve had a warm spell, and the Polar Vortex seems long ago winter’s not over!  It’s still that time of year that freezing and thawing in many parts of the country means ice dams.   We have a great resource found here that will answer your questions about common household problems including ice dams.

There are some solutions to take care of them immediately but know the long term solutions are not from the outside but from the inside of your home.  It has to do with proper air sealing and insulation.

Ice on your roof may be normal, in fact sometimes it’s unavoidable. Don’t accept roof damage, dangerous icicles and roof rakes as just another fact of winter.  Have your home looked at by an energy auditor that can recommend solutions for the long term.

Thanks,

Jason

Fixing Ice Dams Right Now

February 9, 2010

OK, so you know the best way to address ice dams is to prevent them from forming in the first place, with proper attic insulation and air-sealing to keep the heat and warm in your house, and then attic ventilation as the backstop to remove heat that does escape into your attic.

But you live in the mid-Atlantic region, from Virginia and DC to Baltimore and Pittsburgh, and Delware up into New Jersey, you’ve been pummeled with snow, and there is more on the way.  What about the ice dam that is on your roof right now?

First, stay off the roof. Walking on an icy, snow-covered roof is dangerous. And falls even from a low roof can result in serious injury or kill you.

Chipping away at the ice with shovels, axes, hammers is also NOT a good idea. It can damage your roofing (or siding or gutters) and it too is dangerous for you.

Instead, try these temporary home remedies:

  • Use a long handled snow rake–while you stand safely on the ground and far back from where the snow will be falling—to pull off snow from around the eaves.
  • If you’ve already got an ice dam formed, with water building up behind it, fill a panty hose stocking with calcium chloride and lay it so it runs up the roof, across the ice dam. This is a last resort, and the calcium chloride may harm plants below it.  [Amazon sells a special “sock” for thick, but old nylon stockings, or even a cheap new pair from the nearest store,  should work just as well.]
  • If you’ve got water leaking in through the roof, you may be able to stop the leak by sticking a box fan in the attic and having it blast cold air on the leak, freezing the water. Of course, this is a short term fix only, and it works only if the air in the attic is sufficiently cold.

Ice dams can cause water leaks that result in thousands of dollars in damage. The best fix is good insulation and air-sealing to help avoid them in the first place. And it really works. Take action now to avoid the problems coming back in the future.

Thanks,
Mike

Icicles Follow-up

January 9, 2010

A few days ago, we showed pictures of various roofs with evidence of heat loss as demonstrated by strange snow melt patterns and icicles.  Now, a few days later, I wanted to show what’s going on with couple of the homes.

First, the best performing roof still shows a remarkably even snow melt pattern.  Remember, this roof assembly is well air-sealed and insulated to R-60.  We do see a few small icicles on the left side of the roof.  An important point is that it is impossible to completely eliminate icicles, even with a great insulation and air-sealing job.  Outside temperatures, sun, and even depth of snow (since snow itself provides some insulation value) all are factors.  You’ll also see a chuck of snow missing on the right.  This actually didn’t melt off.  A thin layer of melt water under  the snow actually caused a section of snow to slide off the metal portion of the roof this morning.

This second shot, shows another house from the earlier pictures.   This second house is on the same side of the street, facing the same direction, and just a couple hundred feet from the house shown above. Snow on the main part of the house continues to melt fairly quickly.  The snow at the eaves of the two gable ends–not directly above the attic–is more than twice as deep as over the house showing the the house is a big contributor to the melt.  The snow on the addition roof to the right is almost completely gone showing much higher heat loss from this part of the house–an issue that should have been much better addressed at the time of construction.

Again, you can’t completely eliminate heat loss or icicle formation.  But with proper  insulation and air-sealing you can greatly reduce the problem, save a lot of energy, and help your roof last longer.   A good energy audit can show you the way.  And energy-efficiency tax credits and state and utility incentives can often help pay for the improvements.

Read more about icicles, ice dams, and solutions on our website or in a varierty of posts on this blog.

Thanks,
Mike

Snow in Northeast creates conditions for roof icicles and ice damming—signs of wasted energy

January 6, 2010

Burlington, Vermont got hit with a 33 inch snow storm (and several more inches from a couple other storms) last week. Syracuse, Fulton, and much as Central New York are getting pounded with snow much of the last ten days and more on the way. Snow on rooftops often leads to problems with icicles and ice damming, as we’ve discussed here before, but primarily for homes with air leakage into the attic and poor insulation. (Some will tout inadequate ventilation as the cause—but roof ventilation is often insufficient, it can make energy leakage worse, and it’s possible to solve this issue with no roof ventilation!). I thought I’d take a quick stroll and capture some examples of signs that we look for to help spot problems.  These pictures were taken within 30 minutes of each other on homes within a half mile radius of the first home shown.  What a difference good insulation and air-sealing makes!

This first home is an example of what we’d like to see.  An even snow pattern with no signs of excessive melt or ice build-up.  The attic is well-sealed and insulated to R-60+.  This particular home is more than 80 years old–so existing homes can indeed be made more energy-efficient.

This example shows that “New” isn’t always better.  After an extensive remodel completed within the last two years, this home should perform like a newly constructed home.  And in many ways, it does–unfortunately that means not as well as one would expect.  Too often new construction detailing isn’t done well and homeowners don’t really get the performance they should.

Cape Cod style homes are notorious for the poor air-sealing and insulation installation.  The changes in the roof plane and top and side attics require special attention.  More often than not, the details are missed, and the homeowner is left with deficiencies that create an inefficient home.

It’s hard to see in this photo, but there are some interesting melt patterns which probably mean some big air leaks and/or missing insulation.

Again, more recent remodeling means a big missed opportunity to improve efficiency.  I suppose this much ice, though, does make it harder for the neighbors to sign in the first floor windows!

Notice the melting along the ridge, and heat loss at the rafters telegraphing through the snow.

This looks like a semi-cathedralized ceiling, with a fair amout of air moving through the insulated rafter bays–and the ridge vent at the top may be accelerating the heat loss.

Something to think seriously about.  Excessive melting and ice damming is a good way to wreck your roof.  Now, I don’t know if that’s what happened here, but winter is not the best time to replace a roof–it’s generally done only in an emergency.

A fair amount of this home’s heating bill goes toward melting snow!

Now here’s an example of what we’d like to see those Cape Cod roofs to look like (even if this isn’t technically a Cape Cod style house)!

Whoops–looks like someone missed insulation in a couple of bays…

And several more examples follow.  Any ideas what’s going on with these?

Roof killers—icicles and ice damming

November 18, 2009

I touched on insulation and air-sealing in a few recent posts. And as happens in the winter, we’ve noticed a big increase in the last few weeks on people asking about icicles and ice damming. It’s probably time for a quick refresh and retread of an earlier post.

What is Ice Damming?
Big icicles and ice dams are typically caused by poor or missing insulation and air leakage from your house into your attic.  In the winter, this warms the roof and causes the snow to melt. The melting snow then moves down the roof slope until it reaches the cold overhang, where it refreezes.

The process forms icicles and can actually create a dam that eventually forces the water to back up under the shingles and sometimes into the ceiling or wall inside the home. In addition to roof and water damage, ice dams can cause structural decay and mold and mildew to form in attics and on wall surfaces. 

Big icicles are a good sign of too much heat loss through your attic.

Big icicles themselves, like those shown here, are obvious signs that you’re at risk.

But snow melt patterns can also indicate a problem of too much heat loss. In this photo below, you can see snow melting off the roof at different rates, driven by heat loss from the house. 

roof snow melt patterns

Uneven snow melt also is a sign that something is awry

And in the townhouse complex below you can see the building that GreenHomes treated with even snow still on the roof—a sign the building isn’t losing energy rapidly. Conversely, you see the untreated building with the snow melted–a sign that it’s losing a lot of energy. No big icicles this time—but had it been a bit colder, the melting snow would have refrozen at the eaves and created big problems.
treated townhouse retains heat
The townhome treated by GreenHomes loses heat more slowly through the attic and thus snow melts slowly and doesn’t accumulate as ice out at the eaves.
 

  

a leaky and poorly insulation town home attic melts snow quicly

This town home has not been treated and the wasted heat melts snow quickly. In the right temperatures, the melted snow would refreeze and create ice problems--bad news. And in any event, this folks in this building are spending a lot more on energy than they should.

The Fix
Fortunately, you can dramatically reduce damage from ice damming by sealing the holes connecting your heated living space and the attic, as well as properly insulating your attic. There are different techniques to stop air leaking through recessed lights, leaky heating ducts, attic access doors, and plumbing and electrical penetrations. Sealing these leaks keeps warm air in your house were it belongs. Together, with adequate levels of insulation, this greatly reduces the chance of ice damming and large icicles.  You do NOT just want to add more insulation before sealing the air leaks—this can actually create additional problems that can also damage your roof. 

It’s important to not that you can’t eliminate icicles completely.  Small icicles are normal.  And some roof architecture–especially big valleys draining to a small corner–are especially challenging.  But if you have long icicles or thick heavy ice you should act quickly to prevent damage.  (And this means preventing the ice from forming in the first place, not risk life, limb, and your roof trying to chip off ice that’s there.)
 
 Do it right.  Find the important leakage points and seal them up.  Then add a lot of insulation.  And afterwards, as with any time you change the way your house works, have your combustion appliances tested to make sure they’re operating safely and efficiently.

An added benefit to this, of course, is you’ll save energy, save money, and be more comfortable in your home, too!

Save the ice for your holiday cocktails!

[Update, see more roof melt and icicle photos.]

Thanks,
Mike

P.S.  The added insulation can qualify for the $1,500 federal credit.  Save money while you save you roof!


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