Ice Dams, Pantyhose, Salt

By
Home Inspector with Structure Tech Home Inspections

Ever since I was a teenager working at a hardware store, I've heard of people filling up pantyhose with salt and tossing them on their roof to create drainage channels in ice dams.  After hearing about this so many times and even seeing this method of creating drainage channels in ice dams on the news, I began to believe this actually worked.

Nevertheless, I tend to question everything, and last year I finally got around to testing this method on my own.  Instead of laying the pantyhose perpendicular to the ice dam, I laid them parallel to the ice dam in an attempt to get rid of the ice dam entirely.  As I mentioned in my blog about how to remove ice dams, this didn't work well at all.

Several readers suggested I place the pantyhose the way everyone else does (does everyone else really do this?), perpendicular to the ice dams.  The whole idea of placing them perpendicular to the ice dams is to create drainage channels for water, so water doesn't back up in to your house.

I tried this on a cold January day at my neighbors house (thanks for being a willing participant, Jonathan).  I was also curious as to what magical properties the pantyhose possessed.  How do pantyhose make salt so much more effective than salt alone?   Wouldn't it work a lot faster to just put salt directly on to the ice dam?  As it turns out, yes.  This works way better.

The photos from my little experiment are below.  I filled one of the pantyhose up with "Ice Melt", which contained a blend of calcium chloride and rock salt.  I filled the other pantyhose with an ice melting salt that didn't have the contents labeled - I suspect it was just rock salt.  I also poured the Ice Melt in a perpendicular line along the ice dam, using far less salt than I used in either of the pantyhose.

10:00 AM (Start Time)

Salt Filled Pantyhose 10am Salt On Roof 10am

2:00 PM

Salt Filled Pantyhose 2pm Salt On Roof 2pm

4:00 PM

Salt Filled Pantyhose 4pm Salt On Roof 4pm

Hmm... it looks like we have a winner.  If you're going to put salt on your roof, I don't understand what the purpose of using pantyhose is.  The obvious thing here is that salt applied directly to an ice dam is far more effective than salt in a pantyhose.  So you can run and tell that.

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Re-Blogged 4 times:

Re-Blogged By Re-Blogged At
  1. Jacquie Cliff 01/11/2011 08:31 AM
  2. Maureen McCabe 01/11/2011 08:25 PM
  3. Roy Kelley 01/12/2011 06:23 AM
  4. Dan Edward Phillips 01/18/2011 05:00 AM
Topic:
Home Improvement
Location:
Minnesota
Groups:
Ask the Home Inspector
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Tags:
saltfilled pantyhose
pantyhose on ice dams
salt filled socks
salt tubes on ice dams
ice dam removal methods
ice dams
ice dam

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Rainer
170,152
Robert Butler
Aspect Inspection - Montreal West Island, QC
Montreal Home Inspector | Aspect Inspection

Hey Reuben,

We know all about salt here but nobody put it on their roofs although we have the same problems.

Salt can do damage to the roofing materials themselves.

That may be why the practice was to use them in panty hose. The panty hose would keep excess salt out of unnecessary contact with the roofing but melt any snow/ice it was in contact with.

Picking the panty hose up later would also be a convenient way to clean up. Loose salt has to be flushed away with water, so not as convenient or easy to do. Spring rains may not be soon enough to not let the salt damage occur.

There is one other method for ice removal and channel cutting that I don't recall any earlier discussion about: water.

Anybody else know this one? Gotta run but I'll come back to this.

Jan 11, 2011 12:17 PM #16
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Dan - I wonder why it took this long.

Jan 11, 2011 03:11 PM #17
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Brian - this certainly works better than a salt filled pantyhose, but it's nowhere as fast as steam.

Jacquie - I agree wholeheartedly.  Your comment was one of the funniest I've received here on AR.

Maureen - my grandpa used to use pantyhose on trees and shrubs to get 'em to grow straight.  Maybe they could start marketing that.  As for comment #10, I have to assume she thought this was a different post.

Peggy - agreed, that would be my best guess.\

Jay - no, the ice hadn't melted under the gutter - the water just dripped off the front of the ice dam.  Still, it's better than leaking in to the home.

Jan 11, 2011 03:17 PM #18
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Glenn - I'll see if I can talk my wife in to doing that next time.

Jeremy - I got the pantyhose at Walgreens, but not without first explaining myself to the cashier.  She really didn't seem to care one way or the other.

Robert - I've heard other people say that salt can cause damage to roofs, but really, how much damage will it do?  I know another home inspector who serves on some type of 'roof-council-advisory-board' or something, and he told me not to worry about it.  

I've tried picking up the pantyhose after the snow has melted, and the pantyhose just disintegrated, leaving a messing pile of salt on the roof.

As for water, it will just create a ridiculous mess.  Steam is the way to go.

Jan 11, 2011 03:22 PM #19
Rainer
170,152
Robert Butler
Aspect Inspection - Montreal West Island, QC
Montreal Home Inspector | Aspect Inspection

Ok Here goes the story on water.

There are two ways to go. Both are done only after the loose snow and ice have been removed.

The first requires a mild day, preferably sunny. We all know that a water line will not freeze it there is a constant trickle running in it. So this is what we are using here. The garden hose (kept indoors over night to warm it up) is brought out , connected to the spigot and looped over the roof to where you want a channel cut in the ice dam. You run the water just fast enough to keep it from freezing. You can chip a channel for it to run in. Start it on top of the dam just enough to not pond up behind it.

Once you have it going you leave it letting the relatively warm moving water cut a channel in the ice. Admittedly this is not a professional solution and will take time. If not monitored it could make a mess and the hose has to be removed, drained, and brough it as well as all plumbing lines and valves closed and drained when finished for the day. Results will depend on the weather and water temperature. It's touch and go.

The second is simple. Just pour boiling water right out of a kettle to cut a channel. It works and if you are lucky you won't scald yourself. I saw one home owner plug his ekectric kettle into an extension cord and sit down to wait for it to boil. He was sitting for a long time.

Technically this second way is the same as using steam, just a smaller scale.

I don't recommend either.

Jan 11, 2011 05:47 PM #20
Rainmaker
636,934
James Quarello
JRV Home Inspection Services, LLC - Wallingford, CT
Connecticut Home Inspector

You are like some kind of mad scientist with these ice dam experiments :) It's hard to argue with those results.

Jan 11, 2011 07:51 PM #21
Rainmaker
656,515
Realty Works Temecula
Realty Works Temecula - Temecula, CA
Real Estate, Temecula, Murrieta, Menifee

I don't have to deal wiith snow but if I ever do I will remember this post...great idea!

Jan 11, 2011 08:35 PM #22
Ambassador
1,709,161
Margaret Rome, Baltimore Maryland
HomeRome Realty - Baltimore, MD
Sell Your Home With Margaret Rome

Who told you to cut the pantyhose? Once cut they are just hose!

The reason you use panty hose, is so you don't have to carry a bag of salt to the roof and pour it while trying to keep your balance and not fall off the roof!

Margaret

 

Jan 11, 2011 08:40 PM #23
Rainer
639,033
Carl Winters
Canyon Lake, TX

I didn't know they still made those panty hose thingy's. We don't have snow and ice that builds like that here in The Texas Hill Country.

Jan 11, 2011 08:55 PM #24
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Robert - thanks for the detailed info.  Now lets see some photos ;)

James - I just want to be one of the Mythbusters.

Jane - you're lucky.

Margaret - no kidding?  I'll have to re-titled my post: "Ice Dams, Hose, Salt"

Carl & Ceil - they still make 'em, but they're not easy to come by. 

Jan 11, 2011 09:51 PM #25
Rainer
62,507
Mary Jo Quay
Remax Advantage Plus - Minneapolis, MN

I can tell you that I'm not going up a ladder with one hand, and hot tea kettle in the other to pour over an ice dam.  Since most of us winterize out outside spigots to avoid burst pipes, we wouldn't hook up the hose until the spring thaw. 

As for balmy day, WE ARE IN MINNESOTA AND WON'T HAVE A BALMY DAY UNTIL JUNE!  Winter came early, we've had record snowfall and I'm beginning that we will never see green grass again.   I don't think I'll ever see my roof again either. 

Jan 11, 2011 11:42 PM #26
Rainer
62,507
Mary Jo Quay
Remax Advantage Plus - Minneapolis, MN

I can tell you that I'm not going up a ladder with one hand, and hot tea kettle in the other to pour over an ice dam.  Since most of us winterize out outside spigots to avoid burst pipes, we wouldn't hook up the hose until the spring thaw. 

As for balmy day, WE ARE IN MINNESOTA AND WON'T HAVE A BALMY DAY UNTIL JUNE!  Winter came early, we've had record snowfall and I'm beginning that we will never see green grass again.   I don't think I'll ever see my roof again either. 

Jan 11, 2011 11:42 PM #27
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Mary Jo - you can say that again.

Jan 12, 2011 06:11 AM #28
Rainmaker
2,050,369
Roy Kelley
Realty Group Referrals - Gaithersburg, MD
Roy and Dolores Kelley Photographs

Thanks for your timely demonstration. We have a snowy and very cold day in Maryland.

 Life is good!

 

Jan 12, 2011 06:19 AM #29
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Thanks for stopping by, Roy.

Jan 12, 2011 09:28 PM #30
Rainer
39,955
Dale Ganfield
Leland, NC

Hi Reuben, a great experiment with good results.  Now, the next concern is the long term effect of salt application on asphalt shingles.  That sounds like a 15 to 20 year project.  Keep up the great posts!

Jan 13, 2011 08:06 AM #31
Ambassador
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Dagny Eason
Dagny's Real Estate - Wilton, CT
Fairfield County CT, CDPE Homes For Sale and Condo

I just was sent over to this post - I wrote my own on it - we tried the panty hose, did not do anything over 4 days.   We hired a guy to come in this tiny warm spell we had and take all of the snow and ice off of all of our roofs - now we are free of the problems.......

Feb 09, 2011 10:36 AM #32
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Dale - Ha!  If I take that project on, I'll be sure to share my results, but I wouldn't wait around for them.

Dagny - I checked out your post; looks like a big mess.

Feb 09, 2011 03:23 PM #33
Rainmaker
372,284
Donald Hester
NCW Home Inspections, LLC - Wenatchee, WA
NCW Home Inspections, LLC

Reuben,

Your experiment makes perfect sense to me. Since you need the surface contact of the salt to create the ion exchange (melting effect). This could be a fun chemistry project, next you try side by side of Salt (Sodium Chloride) vs Calcium Chloride vs Calcium chloride and Calcium magnesium acetate mix.

Salt is hard on vegetation, calcium chloride is the quickest at melting ice, Calcium Magnesium Acetate  is the  safest for concrete & vegetation.

I think many "Ice melts" use a combo of Potassium chloride and sodium chloride

Feb 28, 2011 11:51 AM #34
Rainmaker
229,465
Reuben Saltzman
Structure Tech Home Inspections - Minneapolis, MN
Minneapolis Home Inspections

Donald - great idea.  I'll have to make all of those tests at different temperatures as well.

Feb 28, 2011 12:04 PM #35
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