Why Does the Snow Melt Faster on Some Roofs?
Winter can show you a lot about your house that you cannot see at other times throughout the year. Have you ever wondered why the snow melts faster on some roofs over others?
The simple answer to this question is that you do not have enough insulation to keep the heat from the house escaping into your attic space and heating up the underside of your roof covering. (There are other factors at play here but this is issue number one to address)
In this diagram you can see that the left side of the attic has poor insulation and is allowing the heat from the house to escape into the attic space and melt the snow. One of the problems that can occur from this is the creation of ice dams. Ice dams can lead to leaks and cause damage at your eaves.
Another problem that can occur is condensation build up at the underside of your roof sheathing. I like to explain it similar to taking a shower. The hot air from your shower meets the colder air in your bathroom and condensation builds up on your mirror. The same can happen in our attic spaces.
You can see that the right side of the attic in this diagram has plenty of insulation and is keeping the heat form the home in the home!
Summary
If you notice that the snow on your roof is melting faster than your neighbors it may be a good idea to stick your head in your attic space and look at the amount of insulation that is installed. If you can see your ceiling joists and walk around, you probably don’t have enough and need to upgrade the amount of insulation your home has.
While you are up there also look for black stains or white fuzzy growth on your roof sheathing. This is another sign that condensation is building in your attic space.