Can I put salt on my roof to melt ice?
Ice dams are formations of refrozen ice that have begun to gather along the eaves of your roof.
The more melted snow flows towards a dam build-up, the larger the dam will become.
Ice Dam Roof Salt
For the fact you’re reading this article, then I can assume you have an ice dam problem. I’ll also take a wild guess and say someone has recommended you use salt to get rid of the dam.
Keep reading and you’ll find out, as I’ll be using the full length of this article to discuss everything you need to know about salt for ice dam removal.
How Did I Get Ice Dams On My Roof?
Ice dams form when your attic receives a blast of warm air which melts the snow in your roof.
The melted snow then flows downwards away from the warm air in the attic and then freezes again when it makes contact with the chilly air outside.
The process is continuous, and as new melts flow downwards, they too will refreeze and that is when the dam will start building up.
In most cases, the newly formed ice dam will gather under your shingles and can even make its way into your roof and attic. As you can imagine, this can lead to extensive damages to your structure.
Roof leaks, broken shingles, and damaged insulation are among the results of an ice dam problem.
Can I Use Salt To Get Rid Of Ice Dams?
The answer to this question swings both ways.
Yes because you can indeed use salt for ice dam removal. And no because some salts (even though they can remove ice dams), will cause some form of damage to your roof.
Let’s take a look at some of the salts you can use to remove ice dams on your roof, as well as the pros and cons of using them.
Rock salt is one of the most commonly used salts for defrosting ice build-ups around a house. Your friend must have already recommended this to you, or you’ve heard rumors of how it is best for ice dam removal.
True, many have successfully used it to remove ice from their driveways, and that can prompt you to believe it’ll work just fine on your roof.
Well, not necessarily!
Rock salt can defrost snow and ice, but it is worth mentioning that it can only do this at temperatures of 20°F and above, not below.
This means that if the freezing conditions are anywhere lower than 20°F, rock salt will not be able to cut the ice build-ups.
Another reason why rock salt is not your best bet for ice dam removal is this – The ice dam you plan to take out is probably too large!
Rock salt for ice dam removal cannot be said to be practical, as the dam is made with hundreds of gallons of iced-out water. And the sheer volume of frozen water that formed the dam can only be broken down by huge amounts of rock salt.
I doubt you have that much rock salt at home. Yes, you can always go to the store to buy as much as you need, and that can help remove the dams. But that’s not all rock salt can do!
You’d be interested in knowing that rock salt can also damage your roof, and the more salt you add, the greater the damage caused.
The shingles on your roof are attached with nails, and rock salt corrodes nails. See why rock salt is a bad idea?
Corroded nails will be packed with rust stains that give your roof an awful look. Rusted nails can also break, and this will leave your shingles loose.
Loose shingles mean roof leaks, and roof leaks mean water damage on the inside of your home.
Many homeowners have tried using table salt to defrost the ice dams on their roofs. And while this can also work, it will produce the same result as rock salt.
This is because both table salt and rock salt are chemically made of the same substance. The former is just rock salt that has been degraded into smaller particles, nothing more!
This means using table salt for ice dam removal will produce the same results as rock salt. And this includes rusted nails and loosened shingles!
Magnesium and Potassium Chlorides
Just like rock salt and table salt, magnesium and potassium chlorides are also effective at melting ice dams. But magnesium chloride can only work well if the temperatures are above 5°F.
As for potassium chlorides, they become ineffective when the temperature drops below 12°F.
Although the good thing about using them is that they won’t corrode the nails holding your shingles together the way rock and table salt can.
As far as what the best salt for melting ice dams is, I’ll have to give it to calcium chloride. And I say this for a good many reasons.
First of all, Calcium chloride does not leave stains behind like the other salts mentioned so far. It can also melt ice dams quicker than sodium chloride.
To add to that, calcium chloride can cut ice at lower temperatures than magnesium, potassium, and sodium. And it can melt larger ice dams.
Calcium chloride has only one minor downside, it can damage wooden gutters. But hey, if you don’t have wooden gutters on your roof then you have nothing to worry about.
If you do, then you should switch over to zinc, aluminum, vinyl, copper, or steel gutters.
With all these in mind, we can agree that calcium chloride is the best salt to use for melting ice dams.
Other salts can also melt the dam formations, but they aren’t very practical and they can corrode the nails on your roof.
I hope the information provided in this article has been helpful.