While ice dams may appear to be an innocent product of winter weather, they can actually cause severe damage and are a serious threat to your roof’s integrity. Let’s take a look at how ice dams form and what you can do to get rid of them — or prevent them from forming in the first place. 

What Are Ice Dams?

Ice dams are ridges of solid ice that form on your roof’s eaves. They are caused by a difference in temperature between the underside of your roof and the roof’s surface during the colder, more snowy months of the year. Sometimes ice dams also form in gutters, where they stop water and snow from moving safely off your home’s roof and instead direct it into your home. Roofs with low slopes are most susceptible to the formation of ice dams, although they can form on almost any type of roof if conditions are right.

Ice dams can be difficult to spot if you don’t know what to look for. Understanding how they form can help you identify areas you might find ice dams on your home’s roof.

How Ice Dams Form

Ice dams form similar to icicles — from the movement of water that later turns to ice on your roof. However, ice dams have far more severe consequences for your roof and your home. Here’s how ice dams form:

  • Warm air underneath the roof melts snow on shingles
  • Water moves down the roof, melting more snow as it goes
  • Water passes down the roof slope until it reaches the eaves
  • Cool air under the roof’s eaves causes the water to refreeze
  • Layers of ice begin to build up on the eaves of the roof
  • Water with nowhere to go seeps underneath your shingles and can develop leaks or start rotting the wood of your roof

Left unaddressed, water can seep through your roof and into your home where it can cause serious damage. Even if you don’t notice a visible leak, any moisture under the roof deck attracts mold and mildew, which may create further damage and compromise your roof.

If your roof has ice dams right now, you’ll need to get rid of them quickly before more damage occurs. Let’s look at what you should do right now, and how you can prevent ice dams in the future. 

Dealing With Ice Dams

Let’s talk about what to do to remove ice dams by first talking about what not to do: never attempt to peel, hack, chip, or scrape ice dams directly off your roof. This method is sure to cause more harm than good. You’re more likely to break shingles or remove them completely — which will let pooling water damage your roof and home that much faster. 

If you need to deal with ice dams on your roof right now, let’s look at two approaches:

Cool the Underside of Your Roof to Stop Ice Dams

Use a fan (or multiple fans) in your attic and direct it towards the roof. The goal of this is to cool the underside of the roof so snow won’t melt and flow down your roof where it can refreeze into ice dams. The downside of this method is that it isn’t effective at removing existing ice dams, but it can help reduce further damage until you can have the problem addressed by a professional.

Use a Chemical Deicing Agent to Remove Ice Dams

Use calcium chloride to melt ice dams. (Note: Never use rock salt, as it will damage your shingles and roof) Position the chemical vertically on your roof, perpendicular to the ice dams, to break them up and create a path for water and snow to travel off your roof. You can hold the deicer in place by using pantyhose. Fill the pantyhose with the chemical, then drape it on your roof’s eaves. The solution is simple and effective, and a good use for that extra pantyhose you likely have lying around.

Ask a Professional

If you have ice dams on your roof and aren’t able to safely remove them, call a professional. A professional roofer will have the tools and expertise to deal with ice dams safely and effectively, and can help talk through your options for preventing them in the future.

Preventing Ice Dams

If you want to save your roof from the dangers of ice dams, here are a few methods you can use to prevent ice dams in the future.

Remove Snow From Your Roof

To prevent ice dams, you can remove snow before it melts and refreezes into ice by carefully raking it off your roof. However, this method is labor-intensive, and if you’re not careful, you could cause damage to your shingles by scraping or pulling them off, or to yourself when snow and ice moves your way. It’s best to have this done by someone with experience — or find a more permanent solution. 

Alternatively, you can use heated cables to melt the snow before it can freeze into ice dams. Arrange heated cables in a zigzag pattern along the eaves of your roof and attach with clips. Cables are effective at keeping ice dams from forming, but are a temporary solution at best. They don’t go after the root cause of ice dams.

Insulate Your Roof to Prevent Ice Dams

Adding layers of insulation to your attic floor can prevent ice dams from forming. This traps heat in the living areas where it belongs and keeps it away from your roof where it could melt snow and lead to ice dams. A professional roofer can assess your home’s level of insulation and see where vulnerable areas could use more protection.

Ventilate Your Roof to Prevent Ice Dams

Adding proper ventilation to the roof — particularly under the ridge and eaves – can help prevent ice dams. Extra ventilation circulates cooler air to the underside of the roof, preventing any snow on your roof from melting and ice dams from occurring and building up in the same places every year. 

A combination of insulation and ventilation is recommended to effectively prevent ice dams. Contact your local roofer to help assess what your roof needs.

Replace Your Roof to Prevent Ice Dams

Whether your roof is due to be replaced soon anyway or you’re tired of dealing with ice dams and damage every winter, you may consider replacing your roof to one that is not susceptible to the formation of ice dams — like a standing seam metal roof.

Standing seam metal roofs don’t provide traction for ice dams to form, so water, snow, and ice are all able to drain off and away from your roof easily. Although ice dams can still form on low sloping metal roofs that don’t have proper insulation and ventilation, it’s very rare. 

The best defense against ice is to outfit your home with the best system to limit the time that snow sits on your roof and to prevent melting and refreezing. If you’re worried about ice dams on your roof this winter, talk to the Werner Roofing team. We’re ice dam experts, and we’re happy to come out, take a look at your roof, and offer a few suggestions or help you get rid of ice dams on your roof.

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