Why Does Snow Melt Faster on Some Roofs

If you walk around your neighborhood a couple of days after a snowstorm, you’ll notice something interesting. Some roofs are caked in snow, while others have none at all. 

What’s going on? 

Snow deposits on properties can behave differently depending on their characteristics. Sunlight should melt snow from above naturally during the thaw, but that doesn’t always happen. It seems like a bit of a mystery. 

Fortunately, we have answers for you. Why does snow melt faster on some home roofs? Let’s take a look.

Why Snow Melts Faster On Some Roofs Compared To Others

There are two main reasons snow melts faster on some home roofs compared to others:

• Homeowners have systems that actively melt the snow (such as heat strips, deicer, etc.)
• Homes are heating the snow passively from within

In both cases, higher temperatures warm the snow from underneath. This process then reduces friction, causing snow to fall off in big clouds or preventing it from accumulating in the first place. However, it can lead to severe issues, as we explain below. 

What Does It Mean If Snow Melts Off Your Roof Quickly?

Fast-melting roof snow isn’t always a good thing. While you might expect it if your roof has heating strips, it could be a sign of insulation problems if you don’t.

Attic insulation retains heat in your home. As hot air rises, it bumps up against a thick foam, preventing it from escaping. 

However, if your insulation has problems, heat will continue to escape, warming your roof tiles and heating the snow from below. Meltwater will then accumulate in ways that damage your property. 

Signs Your Roof Has An Insulation Problem, Causing Snow To Melt Quickly

You can usually tell you have a problem with your roof’s insulation. You’ll notice that snow seems to melt unevenly in patches. Some parts of your roof have a thick layer of powder, while others have none or appear wet. 

Fast-melting snow is another tell-tale sign. If your roof is snow-free, but all your neighbors still have thick layers on their roofs, you probably have an insulation problem. 

You might also notice “snow dams.” These form when meltwater from your roof flows down to colder areas and then freezes again, creating a dam. 

These features can be dangerous because they concentrate weight at your roof’s edges where it is most vulnerable. They can also block your gutters, causing more water to pool on your roof. 

Lastly, watch out for high energy bills. Lack of effective roof insulation forces your HVAC system to work harder and for longer to bring your property to the right temperature. You’ll use more energy. 

A Quick Fix

Fortunately, fixing your insulation is relatively easy. Once it’s done,  you can prevent high bills and dangerous snowmelt features like ice dams. However, you will still need to remove excess snow from your roof if it builds up too much. Compacted snow and ice can cause structural collapse.