During heavy snowfall, your roof is at risk of ice dams, water leaks, and even structural issues.
Salt, a seemingly simple solution, comes with its set of complexities. Which varieties are both effective and gentle on roofing materials?
This guide cuts through the clutter to reveal the safest and most eco-friendly options for roof de-icing, spotlighting Calcium Magnesium Acetate (CMA).
What are Ice Dams?
Ice dams are ridges of ice that form at the edges of roofs, preventing melting snow from draining properly. This can lead to water pooling and seeping into the roof, causing leaks, mold, and structural damage. Addressing ice dams promptly is essential to prevent costly roof repairs.
Is it Safe to Use Salt on your Roof?
No, not all salts are safe for roofs. Some salts can corrode metal components and damage roofing materials. Choosing a safe de-icing agent like Calcium Magnesium Acetate (CMA) is crucial, effective, and environmentally friendly.
Salt can lower the freezing point of water, creating a brine that melts ice and snow on the roof. This can provide temporary relief from ice dams, but it also has potential drawbacks for homeowners.
Metal Corrosion:
Salt can speed up oxidation when it contacts metal, causing rust formation. This can weaken the roof’s structure, creating holes and leaks that may require costly repairs. Salt can affect metal components, including nails, flashing, vents, and gutters.
Roofing Material Damage:
Some types of salt, especially those with impurities, can discolor and deteriorate roofing materials like shingles or tiles. This can reduce the roof’s aesthetic appeal and lifespan. Due to salt-related damage, you may need to replace or repair your roof sooner than expected.
Plant and Soil Damage:
Salt runoff from the roof can harm plants and soil around the house. When salt mixes with melted snow or ice, the runoff can make the soil too salty to retain nutrients and water.
This can cause nearby plants to suffer dehydration and nutrient deficiencies, affecting their growth or survival.
Water Pollution:
Salt runoff from the roof can also pollute water sources. Excess salt can enter groundwater and surface water sources, affecting aquatic life and drinking water quality.
This environmental concern makes it important to choose de-icing agents with minimal impact on the surroundings.
What Kind of Salt is Safe for Roofs?
Sodium chloride, or rock salt, is the most common type of salt used for de-icing, but it’s not recommended for roofs due to potential damage to shingles, nails, and other fixtures. Safer alternatives for roofing include de-icers with calcium chloride or potassium chloride, which are more roof-friendly options.
Rock Salt
Rock salt is a common de-icing agent for driveways and paths. However, it is not suitable for removing ice dams from roofs. Rock salt mixed with water may also run over the roof edge and onto stone or brick masonry.
Rock salt is not very effective method to cure ice dams on roofs. It only works when the temperature is between 20 and 32° F (-6.67 and 0° C). Also, it would take too much rock salt to melt the hundreds of gallons of frozen water in a typical ice dam.
Do not use table salt as a rock salt substitute, for it has the exact same chemical composition (though smaller salt crystals). Table salt and rock salt are the same substance in different forms. They both corrode and stain roofs and walls.
Magnesium and Potassium Chlorides
Magnesium and potassium chlorides can melt ice but are ineffective at low temperatures. Magnesium chloride works only above 5 degrees Fahrenheit, and potassium chloride works above 12 degrees Fahrenheit.
Calcium Chloride
Calcium chloride is the best salt for ice dams, according to handyman Glenn Haege. It does not stain or corrode as much as sodium chloride and melts ice faster and at lower temperatures. It can also melt more ice than other salts.
To use calcium chloride effectively, do not scatter it over the entire ice dam. Instead, fill old pantyhose with calcium chloride and lay it across the dam. This will create a channel for water to run off the roof and break up the dam for manual removal.
How to Use Salt Safely on Roofs
Using salt on roofs can help with ice dams, but it also has some risks. Here are some tips and precautions to use salt safely and responsibly on your roof:
Use Salt Only Where Needed:
Don’t apply salt to the whole roof, only to the edge and the areas where ice dams have formed. Too much salt can cause more problems than the ice dams.
Make Salt Socks or Pantyhose:
To keep salt from spreading or clumping on the roof, put salt in socks or pantyhose and place them along the ice dam. The salt will melt the ice and create channels for water to drain away.
Avoid Salt on Metal or Asphalt Roofs:
Don’t use rock salt if your roof has metal parts, such as nails, flashing, vents, or gutters, or is made of asphalt shingles. These materials can get corroded or damaged by salt exposure.
Wear Protection:
Wear gloves, goggles, and boots when handling salt. Salt can irritate your skin, eyes, and lungs, especially if you breathe or touch it.
Clean Up Afterward:
After the ice dam has melted, clean up any excess salt or debris from the roof and the ground around the house. This prevents salt residue from harming the roof or the environment.
Try Other De-Icing Methods:
If you don’t want to use salt, try other de-icing methods, such as using a roof rake, a heat cable, or a steamer. These methods can remove ice dams without the potential negative impacts of salt.
How to Store and Dispose of Salt Safely
To keep salt in good condition and prevent harm, follow these safety precautions:
- Store Salt in a Cool, Dry Place: Heat and moisture can lower the quality and effectiveness of salt. Keep it in a cool, dry place away from sunlight.
- Keep Salt Away from Children and Pets: Salt can be harmful if swallowed in large amounts or over time. Store it out of reach of children and pets. Use childproof containers or cabinets for extra safety.
- Dispose of Salt Properly According to Local Regulations: Do not dump salt into sewers, storm drains, or waterways. Salt runoff can pollute the water and harm aquatic life and wildlife. Check with your local waste management or recycling center for proper disposal methods.
- Reuse or Recycle Salt Bags If Possible: Empty bags can be used for other purposes, such as storing items or collecting garden waste. Recycling the bags helps reduce waste and environmental impact.
- Store Salt Away from Chemicals and Flammable Materials: Salt can react with chemicals or flammable materials and cause accidents. Keep it isolated in its designated storage area.
How to Prevent Ice Dams in the First Place
The best way to avoid ice dams is to prevent them from forming on your roof. Here are some alternative solutions to ice melt products that you can try:
Improve Attic Insulation and Ventilation:
Heat escaping from the house can warm the roof and melt the snow. This creates ice dams at the roof’s edges when the water refreezes. You can prevent this by insulating and ventilating your attic properly. This will keep the roof temperature uniform and stop the snow from melting.
Install a Metal Roof:
Metal roofs can shed snow and ice better than other roofing materials. Their smooth and low-friction surface prevents snow and ice from sticking and lets them slide off easily. A metal roof can greatly reduce the chance of ice dams forming.
Hire a Professional Roofer:
A professional roofer can help you prevent ice dams with their expertise. They will ensure your roof is installed, maintained, and repaired correctly. They can advise you on the best roofing materials and techniques for your climate and house design.
Seal and Insulate Attic Penetrations:
Gaps in the attic, such as vents, chimneys, and exhaust fans, can let warm air out. This can also cause ice dams by heating the roof. You should seal and insulate these gaps to keep the warm air inside the house.
Install Heated Roof Cables:
Heated roof cables are wires you can put along the roof’s edges and gutters. They produce heat to melt snow and ice, preventing ice dams from forming.
However, you should use them sparingly and follow the instructions carefully to avoid wasting energy. These preventive measures can help you protect your roof from ice dams and potential damage.
A well-maintained roof, with proper insulation, ventilation, and expert installation, is the best defense against ice dams.
What Kind of Salt is Safe for Roofs? FAQs
What Makes Calcium Magnesium Acetate (CMA) the Best Salt for Roofs?
It has many benefits for roofs, such as being biodegradable and less corrosive than sodium chloride. It does not harm plants, animals, or water quality.
It is made from a natural reaction of a magnesium/calcium compound with glacial acetic acid. It can melt ice at very low temperatures, down to around −27.5 °C (−17.5 °F).
It can also be used as a pretreatment on pavement to prevent snow from sticking or for melting ice. CMA is a safe, effective, and responsible choice for de-icing roofs.
How Much Salt should I Apply to my Roof to Melt Ice Dams?
There is no definitive answer to how much salt you should apply to your roof to melt ice dams, as it depends on several factors, such as the size and thickness of the ice dam, the type and amount of salt, the temperature and weather conditions, and the slope and material of the roof.
Use salt sparingly and apply it only to problem areas with ice dams. Excessive salt can lead to runoff, causing potential damage to the roof and surroundings.
Can I Use Salt on Roofs with Metal Components or Asphalt Shingles?
It’s best to avoid using salt on roofs with metal components, as it can lead to corrosion. Asphalt roof shingles themselves are also susceptible to damage from certain salts. Consider using alternative de-icing methods in such cases.
Is Calcium Magnesium Acetate (CMA) More Expensive than Other Salts?
Yes, CMA may be slightly more expensive than other salts. However, its benefits in terms of safety and effectiveness make it a worthwhile investment for roof de-icing, as it helps protect the roof and the environment.
Can I Reuse or Recycle Salt Bags After Use?
Yes, consider reusing or recycling salt bags for various purposes, such as storing items or collecting garden waste, to reduce waste and environmental impact. Proper disposal of salt bags helps contribute to a sustainable approach to roof de-icing.
Conclusion
Choosing the right de-icing agent is crucial when removing ice dams. While many salts exist, Calcium Magnesium Acetate (CMA) stands out for its safety and efficacy on roofs. Always use de-icers judiciously, prioritizing your roof’s health.
Other preventive strategies, such as enhanced insulation, metal roofing, or professional services, can also be considered.