I know many are concerned with snow and ice on their roofs. The forecast for temps in the 30s will be producing some leaking into the interiors of some houses with ice dams. If you can't get up there to rake and shovel, or break up the dams, here's what you can do. Put calcium chloride (ice melt) into a woman's nylon, or a dampened paper bag. Softball size will work. Toss it up 1-3 ft above the dam. This will melt a relief channel down through the dam to give the water a place to go. Also been using smalll laundry bags and, yes, eel bags. Will take a while to work, but won't harm roof shingles. More than one channel is better. Good luck to all.....

The biggest problem is just finding the calcium chloride......good luck!:uhuh:

my ladder is buried under four feet of snow :hs:

i am thinking of snow blowing my way over to it tho
during the better half of SUNDAY (maybe today)

Still waiting for a new pair of neoprene gloves
to arrive from bass pro.... i need em Badly

I have G.H. Duty to do but its mostly hand work....
once you snow blow a relief trench...that is .... next to it
the problem with this damned winter isn't so much
the snow volume but the always below freezing temperatures

and the fact that i am close to having Pneumonia from a severe Battle
with the flu and having to work outside regardless in Blizzard or sub freezing conditions.

Good tip.
Is it Ice Dam or Damn ice?
I think the ice is holding up my gutter, i'm afraid if I touch it, it'll be like the last jenga piece moved before the tower falls. I saw a guy on his roof smashing at the edge with an ice chipper, if he gets thru the ice he's screwed.

Thanks, Ross. I was at my mom's house from 11:30 pm until 1 am on Tuesday night breaking up ice dams because she was getting some water coming into her living room. I'll tell her to do this today and I'll do it at my house, too.

Could the water with the salt enter the house and cause additional damage if I am already getting water now?

i saw on the news they make hockey puck size calcium chlr tablets to chuck up there.

i saw on the news they make hockey puck size calcium chlr tablets to chuck up there.
Are those the same one's I use in my pool? I can't get too them to read the label and my memory isn't that good:o. I know if you get a little water in the bucket of chlorine it starts a exothermic reaction that can actually generate enough heat to spontaneously combust.

Just come from Lowe's.....what a seasonal mess that place is??? They will not be getting anymore calcium chloride in as its "ALMOST SPRING".....they are out??? What an outfit!!:smash:

Just come from Lowe's.....what a seasonal mess that place is??? They will not be getting anymore calcium chloride in as its "ALMOST SPRING".....they are out??? What an outfit!!:smash:


I was in Sears yesterday - they have the Spring clothing in the women's section. I was looking for insulated mittens - they didn't have any.

Their sense of seasonal needs is pretty bad!!:wall:

Are those the same one's I use in my pool? I can't get too them to read the label and my memory isn't that good:o. I know if you get a little water in the bucket of chlorine it starts a exothermic reaction that can actually generate enough heat to spontaneously combust.

calcium chloride tablets and chlorine for the pool are 2 totally different things! Don't throw chlorine on the roof!

Just come from Lowe's.....what a seasonal mess that place is??? They will not be getting anymore calcium chloride in as its "ALMOST SPRING".....they are out??? What an outfit!!:smash:

Christmas Tree Shop at PatPlace is loaded (at least they were 2 days ago).

They had a bunch at Shaw's in Easton the other day. Also, Benny's in Mansfield had it on Wed., but it looked like they were starting to phase the spring stuff in too.

If you can't find any just use mortons pickling salt. Get it wet and make a salt ball and throw it on the roof above the ice damn.

And these saltballs / pucks don't create more problems that what already exists?

Does the meling create even more issues or does the thing go China Syndrome through the ice dam and make a breach?

Guys: remember your storage sheds. They were probably not built to the same standards as home construction, mine sure was not. They will not have ice dams, but the load is still substantial.

In theory, the calcium chloride will melt a trough down and over the frozen gutter. The water has enough of the chemical to keep the opening from re-freezing and prevents a build up which causes the leaks.

You will want to hose the calcium chloride off the roof in the spring, but it will not damage the roof between now and then. It certainly outweighs the damage of leaks to the interior.... but do not use rock salt.

The idea is to make the breach. I don't know about doing it if there is already dripping inside the house or even behind the gutter into the soffet.

What I have seen is putting the Cal chloride in the sick and then laying the sock just behind the ice dam after you have raked about 2 to 3 of snow off above the gutter. That way the salty water as it melts just touches the very ends of the shingles , etc and then into the gutter. Of course accurately placing that sock just behind the dam does require you to get up there on a ladder. I did see one article with a guy who ties a short rope loop around the sock end and then heeoks the sock on a pole with like a boat hook end and he lays the sock down using the long pole instead of climbing the ladder.


Any way you slice it , ice dams are a B1tch. I have seen a problem with them maybe 5 times in the 45 years in my house.


The best way is to do the raking of the snow off the first few feet before the dam forms. If you get a storm that has the wet sticky snow that fills the gutter and has afoot of snow above it , you use a rake or blade on a long pole to rake the snow off as immediately after the storm as you can.

I was talking about the ice melt the size of a softball early today with GF. As I'm shoveling the roof of snow she said that socks are done. Instead of a softball size she made four the size of a large Italian bread. I laid them down near both drains on the north side of the house and the middle. The nylon stretches allowing to cover a larger area.
Thanks for the sock idea.
Posted from my iPhone/Mobile device

The biggest problem is just finding the calcium chloride......good luck!:uhuh:

I got 4 50# bags at HD late this morning. And they seemed to have plenty. But it was priced at $16.97...

Could the water with the salt enter the house and cause additional damage if I am already getting water now?

Not much should be getting in once you release the back up of water with a channel. As for damage, no more than the salt you track in on your boots. Mold behind the walls and wet insullation is a different story....

Another concern would be the impact of CaCl on your landscape, since the salt-laden water has to go somewhere.
(Sounds like the arguement about dumping snow in the rivers and ocean?)

I was talking about the ice melt the size of a softball early today with GF. As I'm shoveling the roof of snow she said that socks are done. Instead of a softball size she made four the size of a large Italian bread. I laid them down near both drains on the north side of the house and the middle. The nylon stretches allowing to cover a larger area.
Thanks for the sock idea.
Posted from my iPhone/Mobile device

Excellent! Tell her she done good! My bigger ones worked better. Made up about two dozen, in various sizes. The longer ones work best vertically or diagonally. I had more than a few smaller ones hit the hard ice and slide off the roof.... They used to sell a product called Ice Viper which was shaped like those draft guards used under doors.

Another concern would be the impact of CaCl on your landscape, since the salt-laden water has to go somewhere.
(Sounds like the arguement about dumping snow in the rivers and ocean?)

With the amount of rock salt in the snowbanks, my lawn will singed 20' back from the curb anyway.... Not one of my clients who have had leaking inside would put the shrubs ahead of the leak. :smash:

("Phuck it, Herb. Those are my prize roses.... I'll live with the leak....)

And it's not like you are putting up a ton of product... just enough to relieve the water back up.

Just thought of this, however... the calcium chloride will disintegrate mortar on brick stairs and walkways. Come spring, the portland will be gone and all that will be left between the brick is sand. Just saying....

I forgot to add...

Some pics show the sock made from nylon stocking legs , etc as being long like a french bread (I think someone mentioned this. These long socks the lay over the ice dam at 90 degrees. The idea is to melt a channel about 2 inches wide straight through the dam to let the water above it drain out. Some show these socks maybe every 4 feet apart.

The biggest spot i am worried about is where a 1 in 12 roof intersects a standard 3 in 12 slope roof. The flatter one has a membraine the steeper has regular shingles. The corner where they meet has a big chunk of ice growing along the both 90 degree directions. Its very high and very thick but especially where the two slabs meet in the corner.. Its also in a spot that is a real pain to get to , even with a ladder. That's the spot I may take the chance and go with the salt socks , etc.

Og BTW , one article was really particular to use the Cal Cl not Rock salt . I don't know why for sure but I think its damage caused by salt assisted corrosion or something like that. Anyway , they say do not use standard rock salt.

I spent 16 hours last weekend busting up the ice dams.

John's site it too much of a pain in the a$$ to post the pictures (sorry John just a little cranky tonight) but I used a 4# Dead Blow hammer I bought at HDP for $30 bucks.

Best $30 I ever spent. 63 years old and standing on a ladder swinging a 4# hammer for 16 hours is no fun. But you know what? All the ice dams are gone and I'm sleeping like a baby.

63 years old and standing on a ladder swinging a 4# hammer for 16 hours is no fun. But you know what? All the ice dams are gone and I'm sleeping like a baby.
Hell, I'd be sleeping like one too if I swung a 4# sledge for 16 hours!!! :uhuh:

-spence

Costco in Avon had lawn fertilizer and other outdoors furniture on display today. It was kind of funny. But for superbowl sunday Costco had about 15 different kiosks where you could get samples of different stuff. I truthfully ate my lunch there today.

W.B. Mason has it. Byu the friekin pallet.

Figures....sold out everywhere.... Maybe could order from their dealer in Poland:smash:
YouTube - The MinnSNOWta Roof Razor Can Be Used By Almost Anyone (http://www.youtube.com/watch?v=L8UZbrhY128&feature=player_embedded)

Or I could ask Paul to make up the business end and stick some conduit to it....

Lodes in South Attleboro is making them up and selling them for the cost of the parts plus $5. People are just grabbing them as they make them. Pretty good deal and it works well too. Handle is long enough to do a ranch house from the ground about 3 feet above the gutters.

The salt balls work great. Learned this from an old timer that I used to live next to. Said it even helped kill the weeds on his drainage around the house. The salt eats a nice path through the ice. You can even break the ice back father tohelp more. Good substitute if you can't find rock salt or calsium.

Poland baby!!!

Ross - What a relief this post is ... or maybe just adding company to my misery ... I just moved into a new townhouse in NBPT ... on MLK day, walked up stairs to a leaking roof ... I was amazed at the amount of water ...

... now I am only renting, and the owner lives in the townhouse next door ... an old house split into two units ...

... when I brought it up to her, she said it happens every 5-7 years and has been happening for the past 20-25 years ... but she cannot afford to get the roof repaired ... I asked her is it worth buying all the other crap she has been spending money on for the past 20 years to not fix the roof? She also told me she only needed to spend $6,000 ... but I will tell you, the leaking happened all week long this week ... if I could capture that water, there probably is enough to alleviate the droughts in Etheopia there is so much coming through ... every 5-7 years ... right, every snowfall seems more like it ...

... she has been hiring guys to come and shovel the snow off the roof, getting overwhelmed by spending $300 a pop ... her boy friend went up there today apparently and shoveled it off ... I guess I should do it myself ... it is a bit hairy up there thought ... but I must say i am a bit peeved to be living in a home that has a leaky roof ... I know it's much more common ...

I will check out this remedy ... I am sick of the leaking water ... I was planning on staying here a few years at least ... but with this roof, not sure I want to ... the ceiling must be totally destroyed ...

My challenge is I have absolutely no knowledge of this kind of stuff, so would prefer the owner to fix it when it's broken ... i will try to follow the suggestions above and inspect the roof for the dams ... thanks

^^^ I don't think I would go up there, you could get hurt, and I would be careful what you do or she may try and blame you for something and force you to finance repairs. Hopefully someone with better knowledge than myself will chime in.

Andy, make sure she makes an insurance claim. You should be covered under your own policy, but use this to force the issue of getting the roof repaired. Re read your lease. It's not like this is the only ice dam claim the adjustors are seeing..... In insurance, misery does like company in terms of settlements. Just don't accept the first one.

Anyone with damage should be documenting everything from cost of buckets to calcium chloride. Photos too. In your case, Andy, you could make a case for witholding it from the rent....

Ice damns are one of the reasons your seeing such a comeback of metal roofs. have one and it works great. The only time I hear the rain on it is in a huge down pour. Works fantastick as to ice damns an such. Been leaving the snow on mine for xtra insulation with all the sub zero nights this yr and am having no problems at all.

I know many are concerned with snow and ice on their roofs. The forecast for temps in the 30s will be producing some leaking into the interiors of some houses with ice dams. If you can't get up there to rake and shovel, or break up the dams, here's what you can do. Put calcium chloride (ice melt) into a woman's nylon, or a dampened paper bag. Softball size will work. Toss it up 1-3 ft above the dam. This will melt a relief channel down through the dam to give the water a place to go. Also been using smalll laundry bags and, yes, eel bags. Will take a while to work, but won't harm roof shingles. More than one channel is better. Good luck to all.....

The application of calcium chloride will kill all plants and small trees that it comes in contact with. Is that true? I have a Japanese Maple in front of my house that I don't want to lose.
Small bushes and shrubs will get killed also....

HD got some snow rakes in during the week. Some **^%%$ came in and the dumb &**&^ at HD sold him ALL of them. Now he's selling them in town for $150 each. he paid $49.95.

Some one is going to burn his house down.

That's one of the reaons the old timers like table or pickling salt. It's not as harmfull as pure calcium.

Home Depot has them up here in Maine. I think you can order on line from them also.

John's site it too much of a pain in the a$$ to post the pictures (sorry John just a little cranky tonight) but I used a 4# Dead Blow hammer I bought at HDP for $30 bucks.

Easiest site in the world to upload pics - don't know what you are talking about :smash:

^^^ I don't think I would go up there, you could get hurt, and I would be careful what you do or she may try and blame you for something and force you to finance repairs. Hopefully someone with better knowledge than myself will chime in.

I wouldn't . I would fall & break my a$$.

HD got some snow rakes in during the week. Some **^%%$ came in and the dumb &**&^ at HD sold him ALL of them. Now he's selling them in town for $150 each. he paid $49.95

Should be worth one of those Hummel reports ;)

Of course accurately placing that sock just behind the dam does require you to get up there on a ladder. .



I can just stand on the snow pile and reach over my gutters :smash: :uhuh:

Thanks - I just went to survey the back of the house ... ice pouring over the entire length of each side of the house, as the back is somehwat of a "U" with a courtyard in the middle between the two units ... some of the icles are about 12-15 feet long, she's off camping in a yurt (sp?) up in Northen New Hampshire right now ... but something has to be done ... just tired of the leaking roof ...

I have a 36" wide gravel rake... the kind you spread blue-stone dust with... I took a 12 foot aluminum fence post, and clasped it to the handle of radiator hose clamps... Free snow rake... MAny people have the components in their garage or shed to make a snow rake... it doesn't have to be a "snow rake" by name from a store to be a snow rake... Works great. Word of caution: Hide your stuff! I live in a decent area, and people have been getting their snow blowers and rakes stolen... someone sees you clearing your roof, knows you have one, and will swipe it

I use a long cable and run it through the chutes of my two snow blowers (Ariens 1032 and 1336 they have metal chutes) and then paddle lock them and cover with a tarp and so far they have not been stolen, if they want them they have to take them both or cut the cable (I think it's a Brinks 15' available where they sell locks, I got mine at lowes). I have started drilling holes in the soffit to allow the water to escape. My brother in law found they just got (Friday night) 4 pallets of Calcium Chloride in at Home depot on 104 in Bridgewater and is bringing me 100lbs. and I've rounded nylons to make some dam busters.:wall:

Today is D day. When the warmer air and rain start , you will either get lucky with some places through the ice dams to let dranage occur or you will get it inside. It doesn't take much to get some drain action. Even if its just running between the house and the back side of the gutter is will keep it from backing up the slope and beyond the overlap of the shinkles.

Piemma did it the best way , just totally remove that ice cap but most can't do that do to lack of equipment (no ladder) lack of strength or lack of know how. Unless you are used to doing handyman stuff , stay off the high ladders etc. A broken neck is worth a million roofs so be smart. Ross's salty balls (that doesn't sound right :) ) will likely save the day for many people.

I'm lacking something for sure but, luckily my BIL isn't. He took my Korkers and jumped right in. We, or really he got the snow off. About 7' up on the backside, which is where it was doing the most damage. We laid Calcium chloride in nylons , pretty much the whole length. Took about 3' of snow off the garage roof and then the front of the house. Most of the snow to about 5'-6' and again with the nylons,. Keeping my fingers crossed, but I am very relieved.
I hope this is only a wake up call.
I'm getting some insulation tomorrow and getting to work.

I'm lacking something for sure but, luckily my BIL isn't. He took my Korkers and jumped right in. We, or really he got the snow off. About 7' up on the backside, which is where it was doing the most damage. We laid Calcium chloride in nylons , pretty much the whole length. Took about 3' of snow off the garage roof and then the front of the house. Most of the snow to about 5'-6' and again with the nylons,. Keeping my fingers crossed, but I am very relieved.
I hope this is only a wake up call.
I'm getting some insulation tomorrow and getting to work.

You let someone on your roof with Korkers...:smash:

I know Mike, that's the second time I've seen that written by people here :confused:

korkers on roof shingles, nice combo

I don't think the Korkers could have caused much damage, the shingles were cold thus I don't really feel they could penetrate the shingles, if they were warm than I could see them penetrating. It's a second layer of shingles that my step father and I put on 22 years ago and it's time for stripping and replacing anyhow, after all the water dam issues. I am going to the Home show next weekend to look into having Interlock roofing installed, unless it's too expensive compared to other options, and now that my stepfather has passed and I no longer have the sack for heights, I'm leaving it to the pro's. Now I'm wondering what type of penetration the Korkers could of had, I think I'll have to experiment with them on some cold shingles, on the ground/driveway which won't have any give unlike the roof. Has anyone found Korkers cause damage this time of year or is it speculation? I still think having the weight off the garage and the ice dams under control will be less costly than what the Korkers could do, time will tell and perhaps it will be another lesson learned:confused::wall:

Best cure in the world for ice dams: bright sun and 40-45 degrees!

We're working on the roof today. Roof rakes and calcium chloride filled socks. Just taking a five minute break right now.

I see, better to be safe than on the ground with a broken neck or worse.

I was out on the ladder last nite around 9:30 as i had water coming in thru the top of my kitchen window and also out the window sill. I up there hacking away with the claw end of a hammer as i have in past years and it starts to thunder and lighting out for Pete's sake. I got the damn cleared in the area that needed it and went out today and cleared all the gutters and ice dams till next time. Beauty of a day out, lots of mealting. Now my driveway is a whole different matter. Friggin skating rink. Got stuck this morning trying to go to church but the good lord saw fit for me to get unstuck. I need some snow on my driveway to fill in the ruts and give me some traction.

Well todays a balmy 40 degree day it will do some good for drainage it looks like the weather will be in the low 30's for the next few days,this is good news.
I had some water work its way into my master bed room I looked in the attic and it wasn't as bad as I thought,looks like im spending my tax money on a new roof.
With all of this talk on the news with roofs collapsing I looked out at my camper and saw at least 20-24" snow on it:smash:Today was a good day to take advantage and shovel it off,maybe just naive or lucky but better safe then sorry.

Anybody have a good source for heat tape? The best I found online was 4.64 a foot. Looking to this coming summer doing the North side of the house, garage and the gutters

Was able to get some salt bombs up on the roof, about six or so ... so far so good ... also the warm weather was real helpful as well ... bought a lot of extra if need be.

Swung back into the hardware store this morning, and must say, I was amazed at the amount of people there discussing their problems with ice dams ... dozens and dozens of people in this one hardware.

Rock salt flying off the shelves

I ended up using the water softening salt (blue bags) in the nylons for the front of the house and it worked well. Because of the gutter guards they slid off with what was left of the ice dams and it looked like some sort of perverted toilet papering type prank out front with nylons hanging in my bushes and laying on the snow banks:rotf2:

I too got some water in the kitchen and my den last night... Seems I had been paying too much attention getting my clients' houses freed up, and didn't quite clear enough of the ice on my own house.:smash: So I too was up on a ladder in the dark and the rain last night.... Also had it follow my vent pipe right down to my basement.... Spent hours today clearing up to 26" drifts that were still up there. Four straight days of this. I'm whipped.... Glad if my suggestions were able to help some of you out. If so.... as Bassmaster would say, you owe me a plug!:rotf2:

I ended up using the water softening salt (blue bags)


That is what Lowes on Rt106 W Bridgewater was pushing as DeIcer! Obviously they were out of the standard calcium chloride...

That is what Lowes on Rt106 W Bridgewater was pushing as DeIcer! Obviously they were out of the standard calcium chloride...
Bingo thats the place, it worked and was only a little over $5 for a 40lb. bag.

I didn't have ice dams or leaks, but I did have frozen solid gutters. I got up there with a ladder and a shovel and cleared off the snow about six feet up from the gutter. With the warm weather today - 43 degrees - the ice in the gutter melted no problem. The only problem I have is when the gutter freezes up and the melt water from the snow runs over the gutter and down the outside of the house. No problem today, but I still have ice in the back gutters - less sun back there.

I have electric heat wires on the roof and in the gutters.. i rake after every snow fall... I have the only house on the street with out ice dams....

the reason for CaCl is because it relies on a chemicle reaction to work ( just add water) rock salt requires help from the sun and warmer temps...

My lawn is crab grass.... i couldnt kill it if I wanted to...

I have electric heat wires on the roof and in the gutters.. i rake after every snow fall... I have the only house on the street with out ice dams....

the reason for CaCl is because it relies on a chemicle reaction to work ( just add water) rock salt requires help from the sun and warmer temps...

My lawn is crab grass.... i couldnt kill it if I wanted to...


Rock salt is Sodium Chloride - NaCl. Calcium Chloride is CaCl2. When NaCl dissolves, there are two ions - one of Na and one of Cl. When CaCl2 dissolves, there are three ions, one of Ca and two of Cl. That's why Calcium Chloride works better. Both are chemical reactions - they lower the temperature at which water freezes - so they cause ice to melt as long it the temperature is above the new freezing temp.

Look at the size of the brain on mark!

BSD-135: Ice Dams — Building Science Information (http://www.buildingscience.com/documents/digests/bsd-135-ice-dams/?searchterm=ice)
This site is worth looking at when you try and figure out what to do to permently solve your problem

Rock salt is Sodium Chloride - NaCl. Calcium Chloride is CaCl2. When NaCl dissolves, there are two ions - one of Na and one of Cl. When CaCl2 dissolves, there are three ions, one of Ca and two of Cl. That's why Calcium Chloride works better. Both are chemical reactions - they lower the temperature at which water freezes - so they cause ice to melt as long it the temperature is above the new freezing temp.
I hate to nitpick, but isn't dissolving a physical change? You mix table salt into water, then evaporate all the water and you'll still have table salt. If it were a chemical reaction, then a new compound would have to be created.

Dissolving salts into water raises the boiling point of water and lowers the freezing point. I believe calcium chloride lowers the freezing point more than NaCl would and is why it is more effective at dealing with ice.

I always loved chemistry in college is high school.

I hate to nitpick, but isn't dissolving a physical change? You mix table salt into water, then evaporate all the water and you'll still have table salt. If it were a chemical reaction, then a new compound would have to be created.

Dissolving salts into water raises the boiling point of water and lowers the freezing point. I believe calcium chloride lowers the freezing point more than NaCl would and is why it is more effective at dealing with ice.

I always loved chemistry in college is high school.

No quite correct, JD.

Is mixing calcium chloride and water a chemical reaction?
Answer YES

CaCl2(aq) + H2O(aq) = 2HCl(aq) + CaO(s)

You con't get CaCl2 back.

More importantly for melting snow: the reaction is exothermic giving off HEAT.

http://www.youtube.com/watch?v=GYy9B6vnCtI&feature=player_embedded

(thermometer is in Celsius)

All I know is that working all day with two other guys and plenty of calcium Chloride got most of the ice dams off of my roof.

Look at the size of the brain on mark!


that made me chuckle out loud... have no idea why. :rotf2:

No quite correct, JD.

Is mixing calcium chloride and water a chemical reaction?
Answer YES

CaCl2(aq) + H2O(aq) = 2HCl(aq) + CaO(s)

You con't get CaCl2 back.

More importantly for melting snow: the reaction is exothermic giving off HEAT.

YouTube - Dissolving Calcium Chloride: An Exothermic Process (http://www.youtube.com/watch?v=GYy9B6vnCtI&feature=player_embedded)

(thermometer is in Celsius)
That's right, forgot CaCl2 is one that actually reacts with water.:smash:

Is it called the eutectic point ?
Haven't thought of it since Charlie Waughs 1972 chemistry class, all I wanted to do was burn stuff . . . . . boy did I ever.:grins:

Nope , you had it right Johnny D.

When we use either CaCl2 or NaCL to melt ice , its because it lowers the melting point of the water. There is virtually no contribution of an exothermic reaction at the very low levels it gets diluted to when you use a sprinkle of salt on an icy surface. yes , a spoon full in a small amount of water will raise the temp but for the use in melting ice , its all Phase diagram stuff , not exeothermic reaction. It actually will lower freezing point to -50 degrees at a 30 wt% solution but my guess is that at the concentrations we use , it might lower it 4 degrees or so.

The experiment to prove this using the video shown , would to be to put the reacted mixture that was raised to 50C inot a freezer. The freezing point of the water would be way low , maybe approaching -50 C at the concentration he used. Remember , in the freezer you are not taking the salt out. You are just taking heat out and even though all the heat of the reaction is gone , the water with the same salt in it still has that hugely lowered melting point.

To read more , search for "water/Calcium Chloride Phase Diagram.

Saltheart
MIT 77 :)

Didn't see makai's post.

the eutectic point is that specific concentration of salt and water that has the lowest melting point of all the possible concentrations. It aloso needs to transform from a total Solid to a total liquid to be a Eutectic point. If it is at a concentration that turns to slush , some water and some solid , its not a eutectic point , its just some point along the partial fraction liquid + solid phase line.

Eutectic= complete solid to liquid transformation on heating at one specific concentration where the melting point is the lowest

Think my head just got a little bigger,
now I wanna make some homemade ice cream the old fashioned way !

Nope , you had it right Johnny D.

When we use either CaCl2 or NaCL to melt ice , its because it lowers the melting point of the water. There is virtually no contribution of an exothermic reaction at the very low levels it gets diluted to when you use a sprinkle of salt on an icy surface. yes , a spoon full in a small amount of water will raise the temp but for the use in melting ice , its all Phase diagram stuff , not exeothermic reaction. It actually will lower freezing point to -50 degrees at a 30 wt% solution but my guess is that at the concentrations we use , it might lower it 4 degrees or so.

The experiment to prove this using the video shown , would to be to put the reacted mixture that was raised to 50C inot a freezer. The freezing point of the water would be way low , maybe approaching -50 C at the concentration he used. Remember , in the freezer you are not taking the salt out. You are just taking heat out and even though all the heat of the reaction is gone , the water with the same salt in it still has that hugely lowered melting point.

To read more , search for "water/Calcium Chloride Phase Diagram.

Saltheart
MIT 77 :)
So... Phil and I are both kind of right?

So... Phil and I are both kind of right?

I like that...on a grand scale. I'm a single molecule scale guy!

If there is no water and its below freezing...each crystal/molecule CaCl2 on a molecular scale reacts with snow/ice to generate water based upon mini-exothermic reactions, e.g. ice melts. The thing cascades and makes more water which dissolves more CaCl2. The more water the more CaCl2 dissolved the lower the freezing point which causes more ice to melt.

I am confused, doesn't the solid calcium chloride generate heat untill it becomes liquid when exposed to water, either solid or liquid?

I am confused, doesn't the solid calcium chloride generate heat untill it becomes liquid when exposed to water, either solid or liquid?

Stay confused, sometimes we are better off that way!:rotf2:


Point 1: yes when adding solid/dry CaCl2 to water it will get warmer. The more CaCl2 the warmer it gets. The mixing is "exothermic".

Point 2: CaCl2 in water will lower the freezing point of that water. Again, up until 30% (w/v) that freezing point depression will eventually reach -50C. (Question: anyone know how cold -50C is? DAMN COLD!)

When determining the freezing point (or eutectic point) of a given solution of CaCl2 in water it doesn't matter at what temperature the CaCl2/water solution starts from, it is not a measure of how many BTU's to cool only at what point does the solution freeze. So if I take room temperature water, add CaCl2 depending upon how much CaCl2 it may get detectably warm (to the hands or see movie above), then cool it down to freezing it will still have the same measured freezing point whether I start from room temperature water, warm/hot water, or even cold water. The graph attached earlier takes 20 or more different solutions of CaCl2 in water and measures the freezing point of each solution.


Side point: Car antifreeze, ethylene glycol, if you mix 2 parts anitfreeze with 1 part water you get a solution that freezes at ~70C. Don't mix ratios in any greater as the freezing point rapidly rises!

Here is another solution. I take all my rigged eels which have been soaking in brine solution for years and place them on the ice dams. They slowly emit brine solution and keep my gutters free of ice. As long as it's cold the eels stay fresh - just don't leave them on your roof in the spring time. :)

DZ

I honestly don't know about what happens when the first solid water and solid CaCl2 meet. What you need to think of is all the CaCl2 he had to add to just 50 CC of water to get a 25 degree rise. All that saly would have melted 100 times more water do to the lowering of the freezing point where as that much heat 50 CC X 25 degree rise at 1 cal per degree =1250 cal. That isn't much heat when you think of all the area of snow , the weight of the ice , the latent heat of fusion of the water which is 80 cal /gram (1gram of water is 1 CC) . The exothermic heat is just such a drop in the bucket that its effect in melting real ice amounts on a roof or road , etc is negligible. I will give you that there may be some roll of the heat of reaction in initiallizing the process as I'm just not at all sure but my gut reaction is that even that is not true or if true again almost insignificant beyond just getting the first few molecules of water to go liquid.

But anyway , I think we all now have enough Physical Chemistry knowledge of the salt/water reactions and Phase equilibrium to last us a lifetime. :)

Here is another solution. I take all my rigged eels which have been soaking in brine solution for years and place them on the ice dams. They slowly emit brine solution and keep my gutters free of ice. As long as it's cold the eels stay fresh - just don't leave them on your roof in the spring time. :)

DZ

DZ- THAT IS CLASSIC:rotf2::rotf2::rotf2::rotf2:

The one point of the building science thing that I posted is that the reason you get icedams is you are losing heat thru the roof. If you do the things they suggest you will 1. Not have ice dams 2. Save money on fuel. Sometimes the cure can be done in less time than it takes to chop off ice dams. Most airsealing and insulation upgrades are pretty low tech.

where would we be without PRBUZZ to straighten us out on all things involving chemistry and hot babes?

The one point of the building science thing that I posted is that the reason you get icedams is you are losing heat thru the roof. If you do the things they suggest you will 1. Not have ice dams 2. Save money on fuel. Sometimes the cure can be done in less time than it takes to chop off ice dams. Most airsealing and insulation upgrades are pretty low tech.


The most important point of all. I had cracks running up the corners of four closets that I finally patched this year. That warm air getting out of the rooms and in to the wall interiors goes straight up to the attic. I also taped over all the unused wall sockets. Add this to the attic insulation I've done in the last couple years and I've got more snow on my roof than any neighbor - because my attic is so cold. I did get ice in my gutters, but none on the roof itself, and no water leaks.