A well-insulated attic keeps your home comfortable. Sadly, however, many homeowners do not have enough insulation in their attics. Here are four signs you need to add another layer:

You only have one layer of insulation.

Insulation needs do vary somewhat by climate, but unless you're in an area where the temperature stays a pretty comfortable, constant, 60–70 degrees year-round, chances are good that you need at least two layers of insulation in your attic. If you only have one layer, then unrolling a second layer of fiberglass batt insulation in the direction perpendicular to the bottom layer is a good way to lower your energy bills and keep your home more comfortable.

Your upstairs feels drafty.

Do you feel like cold is coming in from the ceiling above you when you spend time in the upstairs of your home? Even if you have two layers of insulation in your attic, draftiness is an indication that you need more. You could unroll a third layer, or you could also purchase a can of spray foam insulation at the local hardware store. Use the spray foam insulation to fill in any cracks and crevices you see in the attic walls and ceiling. This will block the flow of air, providing some extra insulation in addition to the layers of fiberglass.

There are ice formations on the edge of your roof.

During the winter, take a look at the edge of your roof. Do you see large icicles or ice formations? Though they may be attractive, these formations mean that snow is melting near the peak of your roof. This indicates that too much heat is escaping from your roof -- due to a lack of insulation. Upgrading your insulation is vital here since the formation of these ice dams can cause the shingles to peel or crack.

The insulation you have appears compacted or moldy.

Take a look at your insulation itself. It should still look fluffy and dry. It it appears matted, compacted, or discolored, this means it is no longer doing its job as well as it could. You should really peel it up and replace it with new insulation, but putting a new layer over top of it is better than nothing.

To learn more about attic insulation, reach out to a roofing contractor such as Select Exteriors in your area. Most also offer insulation services and will help you choose the proper insulation for your attic, if needed.