Ice Dam Help

[ecduzitgood]

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

[Pete F.]

BSD-135: Ice Dams — Building Science Information
This site is worth looking at when you try and figure out what to do to permently solve your problem

[MakoMike]

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.

[Saltheart]

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

[MAKAI]

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

[Saltheart]

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.

[Pete F.]

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.

[MarkB]

Originally Posted by Pete F.

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.

[blondterror]

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