Reuben's Home Inspection Blog

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How To Get Rid Of Ice Dams

 

Last year at about this time I wrote a blog about ice dams, covering what needs to be done to prevent ice dams from happening, both on the inside and outside of the house.   This year I'll discuss a bunch of different ways to get rid of ice dams.  The methods involve axes, ice picks, pantyhose, salt, and heat cables.

Ice Dam 3

Axe

The most obvious way to get rid of ice dams would be to just take a blunt instrument and hack away at the ice dams.  I tried an axe.

Axe

Pros: Fast results - I hacked through several feet of six-inch thick ice dams in a matter of minutes.

Cons: Unsafe and cumbersome.   I had to set up a ladder on the icy ground and swing an axe while standing on a ladder.  The ice also really flew in my face - I should have been wearing goggles!  I was only able to remove the ice down to the gutter, and only able to get close to the surface of the roof without risking damage to the shingles.

Verdict: This is a high risk, but fast and effective way of getting rid of a lot of ice, but leaves the job incomplete.

Ice Pick

Sounds like a natural choice, doesn't it?  I actually used my awl, but close enough.

Reuben's Awl

Pros: Very fast results, very little effort.  It's as though this tool was made for picking at ice.  Oh, wait...  Still, I was genuinely surprised at how fast and accurate this method was.

Cons: Unsafe.  Again, I was jabbing at ice dams while standing on a ladder, which was sitting on the icy ground.  I also had to be very careful to not damage the roof.

Verdict: This is definitely my method of choice.  Nothing else worked nearly as well.

Roof Tablets

Yes, this is a product designed specifically for preventing damage from ice dams.  Contrary to the name on the container, the product doesn't actually melt your roof (whew).  The instructions say to toss the tablets on to your roof and they'll melt through the ice dams, allowing for "water to drain safely".

Roof Melt Tablet Container

Roof Melt Tablet Instructions
Roof Melt Tablets

I tried tossing the tablets on the roof like the instructions said to do, but it didn't work out very well.  I consider my tablet tossing skills to be above average, but I still couldn't get the tablets to end up in a good location - they all just slid together in one place.  If I didn't get a ladder out to take pictures, I never would have known that the tablets didn't end up in a good spot.

Roof Melt Tablets Tossed

Just to give the roof melt tablets the best possible chance for success, I hand-placed them on the ice dam and I used about four times as much as the directions called for.

Roof Melt Tablets Placed Day 1

By day two, I had some pretty dramatic results - the tablets had melted all the way through the ice dam.  btw - for anyone in a southern climate that might be reading this blog, that white stuff on the ice is snow, from a very light snowfall the night before.

Roof Melt Tablets Day 2

By the third day, not much change.  There were definite holes in the ice dam, and some channels had formed for water to drain through, but the majority of the ice was still there.

Roof Melt Tablets Day 3 #2 Roof Melt Tablets Day 3 #1

Pros: If you had perfect aim and tablets didn't move after you tossed them on to the roof, this would be very safe.

Cons: The tablets don't stay where they land, which negates the whole safety thing - I still had to set up a ladder on the icy ground and move the tablets around myself.  This method was also pretty ineffective - it created a bunch of holes in the ice dam, but so what?  Most of the ice dam was still there in the end.

Verdict: This might be a nice way to get down to the roof surface, and it would be nice to follow up with an ice pick after a day or two, but the tablets alone aren't great.  Sure, it's safe... but so is sitting inside a warm house.  Neither gets the job done.

Salt Filled Pantyhose

This is a simple, straight-forward approach.  Take off your pantyhose, fill 'em up with ice melt (calcium chloride or something similar), and toss 'em on your roof.  The idea is that the salt will leak through the pantyhose and eventually melt the ice dams away to nothing.   This is supposed to work better than just putting salt directly on the roof, because salt applied directly to the roof will just melt a bunch of tiny holes, much the same way the tablets melted large holes.

Salt Filled Pantyhose Day 1

By day two, there were several tiny holes in the ice dam.  Whoop-de-doo.  Salt alone would have done this.

Salt Filled Pantyhose Day 2

By day three, the pantyhose had started to melt in to the ice dam, and had completely melted down to the roof.   The part that hadn't melted down to the roof basically had a hard, crusty layer of salt(?) formed on the bottom of the pantyhose, and nothing else was happening.  I picked up the pantyhose, broke up all the chunks of stuck together salt, and placed it back down.

Salt Filled Pantyhose Day 3 #1 Salt Filled Pantyhose Day 3 #2

On day four, I tried moving the pantyhose again to loosen up the stuck together chunks of salt, and the pantyhose ripped apart, leaving a big mess of salt on the roof.  Yuck.

Salt Filled Pantyhose Day 4 #1
Salt Filled Pantyhose Day 4 #2

Pros: This is pretty safe.

Cons: Took way too long and didn't do much.  Waste of time.  I wonder if I can return the pantyhose to Walgreens?

Verdict: Better than nothing.

Heat Cables

For the record, heat cables aren't supposed to be placed directly on ice dams, but some people might try it anyway.  My friend did this at a house he owns in Saint Louis Park... so I took pictures.  These photos all show the heat cables after about one day.

Heat Cables #2

Note the creative way of keeping the cables from touching each other.  Pretty cool, huh?

Heat Cables #3
Heat Cables #4
Heat Cables #6

Pros: Gets the job done, and will prevent the formation of ice dams throughout the rest of the year.

Cons: Heat cables aren't made for this, and I'm sure the manufacturer would tell you that this poses some type of safety hazard.  Stringing up the cable was also very unsafe.  It's a good thing my friend owns a jet pack.

Verdict: Don't do this.

Summary

An ounce of prevention is worth a pound of cure.  My favorite method was definitely the ice pick, but this was also very unsafe, and there's a good chance that the roof surface could get damaged this way.  I'd rather not have to deal with ice dams at all.

After a good snowfall, rake the snow off your roof.   This definitely takes the least amount of effort and it's safe.  I've been asked whether a roof rake will damage the roof, and the answer is definitely no.  A good roof rake will have little wheels at the bottom of the rake , which prevents the bottom of the rake from even touching the surface of the roof.  Rake away.

Roof Rake Head

POST EDIT 1/6/10:  The following video shows how a blowtorch will work. http://www.youtube.com/watch?v=8g8dENlmoMY

RELATED POST: How To Prevent Ice Dams

 

Reuben Saltzman, Structure Tech Home Inspections

        

Comment balloon 30 commentsReuben Saltzman • January 05 2010 06:34AM

Comments

Reuben....thanks....that was an interesting post.....great information...

Posted by Barbara Todaro, "Franklin MA Homes" (RE/MAX Executive Realty ) almost 9 years ago

I didn't know you had to go through so much there to get ice off your roof! I don't think anyone here in NYC does that!

Posted by Luke Constantino, Residential/Commercial Real Estate Brooklyn NY (Brooklyn/Manhattan Real Estate) almost 9 years ago

Thanks for the advice. I have to agree that preventing ice dams is the best way to go, usually by creating better attic ventilation through the soffits

Posted by Al Wright (Affordable Canadian Home Inspections) almost 9 years ago

Reuben,

The pantyhose method is only safe if you are not on the ladder when your remove your stockings!

Posted by Irene Kennedy Realtor® in Northwestern NJ (Weichert) almost 9 years ago

Thanks Barb.

Luke - most people don't.  They just let the water and ice cause damage to their roof, or they let the ice & water shield that gets installed below the shingles do it's job.

Al - ventilation is a great way to help prevent ice dams, and the best is to prevent the heat loss in the first place; seal those bypasses!

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Irene - that's an excellent point that I forgot to mention, thanks for the tip.  

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Reuben I would imagine it is very difficult to get enough insulation in the attic to prevent ice dams alltogether because of their being no room at the eaves.  I would be tempted to wrap a "soffit" all around the interior with insulation to improve the depth in that area.  How insulated are the ceilings currently?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

Reuben, I forgot to add.  Have you seen that core-vent material that can be used to vent the ege of these roofs with no soffits?  I will see if I can find a link if you want----because certainly good ventilation is really important in conjunction with tons of insulation.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

You forgot a blow torch! :)

Posted by Vince Santos, Southeast Michigan Home Inspector (StepByStep Home Services LC) almost 9 years ago

Charles - yes, on older houses it's very difficult to get the eaves properly insulated.  On newer houses they're just built up taller at the eaves to allow for proper insulation.  At my own house, I have about 4" of polyurethane foam sprayed in there, for an approximate insulating value of R-28.  

You said you would be "tempted to wrap a soffit all around the interior with insulation"... I don't quite follow.  Do you mean you would insulate the part that overhangs?    

I've see the core-vent stuff you mention, and I considered using it at my house before I decided to go with a 'hot' roof, but most people said it doesn't do much good after it gets covered with snow and ice, so I decided to skip it.

Vince - You're right.  I've tried it, and it doesn't work for crap.  I was going to include some photos of how poorly it works, but my propane tank is almost out and I didn't want to run to the store.... but now that you mention it, maybe I'll have to write an addendum to this blog.  

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Reuben, I was thinking around the interior of the rooms.  My next question is why is the attic so warm---at least right at the eaves?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

The attic will actually be coldest at the eaves. That's what causes the melted snow to re-freeze right at the eaves.  The attached diagram should help.  Don't get too hung up on the idea of preventing ice dams with ventilation - this isn't the best way to prevent ice dams.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Oh, I know that Reuben----just trying to figure out what is melting the snow so that it freezes when it gets to the cold part.  If the attic is at the same (or close) temperature as the outdoors the snow should just sit there without melting.  Now sun hitting one side could warm up the attic enough to melt the snow and the non-sun side of the house could melt and freeze at the overhang----and this is where ventilation would be crucial to keep the attic temp down even with the sun hitting it.

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

Charles - lol, of course you know this stuff!  It seems to be more more dependent upon what is going on inside the house where the heat loss is occurring, and happens much more with low-sloped roofs.  Steep roofs don't have these problems.  What's melting the snow is lack of insulation and attic bypasses... but you already know that.   

Ventilation would obviously help, but on these old 1 1/2 story houses that were never meant to have finished attic space, adding proper ventilation becomes a huge project that is usually just not cost effective.  It does work though.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

AHHH yes the ole finished attic story :)  These old dinasaurs are hard to coax into the 21st century aren't they?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

You bet.  I hate inspecting these.  I can rarely find anything positive to say about the insulation, air leakage, and ventilation situation.  I usually tell my clients that they're buying a house with a huge finished area that can't be made right without tearing it apart and redoing everything.  

Why did I buy one of these?  sigh...

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Yes Reuben, but when you figure out a way to do it you will be well on your way to your second million:)

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

Reuben:  I am impressed at your comprehensive blogs!  Very good stuff.  I am glad that I am subscribed to you because you are a consistent producer of valuable, interesting and enlightening information.  We don't deal with ice dams in this neck of the woods but I loved the dissertation!  You must have been preparing for this post for a while.  Very nice research, supporting pictures and presentation.

Posted by Jim Allhiser, Salem, Oregon Home Inspector (Perfection Inspection, Inc.) almost 9 years ago

I thought that global warming would be the answer to ice dams.

Posted by Associate Broker Falmouth MA Cape Cod Heath Coker, Heath Coker Robert Paul Properties Falmouth MA (http://www.CapeGroup.com & http://www.REindex.com) almost 9 years ago

Charles - second million?  You're a funny guy.

Jim - you're too kind.  You're very lucky this isn't an issue for you.  The one request that I've received from a few different people now, not just Vince, is to try out a blow torch.  Look for a video on that soon!

Heath - yeah, right?  Global warming, my awl. 

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Hey Reuben since so much of the ice seems to be in the gutter----how about heating the gutter?

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

Heating the gutter would definitely work.  I see three ways of doing it:

1. Lay a heat cable inside the gutter, preferably the type that is made just for this as a preventative measure.

2. Use a blowtorch.

3. Induce a current across the gutter, and let the resistance of the gutter cause it to heat up.  That's safe, right? 

Any other thoughts?

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Ok Vince, here's your blowtorch method.  I bought a new tank of propane and made a video: http://www.youtube.com/watch?v=8g8dENlmoMY

I haven't paid for a premium membership at AR, so I can't embed this video in my blog.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Reuben in relation to choice #3----especially in conjunction with that spiffy aluminum ladder:)

Posted by Charles Buell, Seattle Home Inspector (Charles Buell Inspections Inc.) almost 9 years ago

We melted our ice dam with hot tapwater in buckets and garden water pails carried to my one handed husband on a ladder.  Then we put down the heat tape/cord thingy to hopefully prevent until we can afford to get proper ventilation.

Posted by Mary in Nebraska almost 9 years ago

Mary - that sounds like a TON of work!  How long did that take?

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) almost 9 years ago

Hi Reuben!  I ran across your post as a reblog on Mary Strangs blog.  Coming from sunny AZ I had no idea what an ice dam was.  Your commentary was educational (and humurous).  I had to chuckle.  Loved the pros, cons and verdicts.

Posted by Kathy Anderson, Arizona Retirement Homes For Sale, Sun City Grand (HomeSmart) over 8 years ago

Reuben - I found this post through a re-blog by Cindy Jones.  I'm going to link to it from a post on FocusOnCrofton.com one day next week.  Very helpful!

Posted by Margaret Woda, Maryland Real Estate & Military Relocation (Long & Foster Real Estate, Inc.) over 8 years ago

Hi Kathy, I don't know how I didn't see your comment from a month ago... you're lucky that you never have to deal with this stuff.

Margaret - I'll keep a look out for it, thank you.

Posted by Reuben Saltzman, Delivering the Unbiased Truth. (Structure Tech Home Inspections) over 8 years ago

Reuben,

Great post.  Good information and funny.  I certainly need this information.  My next choice would be to wait for spring and warmer weather, but I might have water coming through my ceiling if I wait that long.

Posted by Ron Trzcinski, 410-935-5844 (Century 21, The Real Estate Centre, 410-665-0200 Office) over 8 years ago

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