Signs of Poor Insulation
A home's insulation is its best defense against heat loss. Insulation works by trapping air which is a good insulator. Adding insulation will reduce your heating and cooling bills and create a more comfortable environment. Insulation can be installed inadequately, be mechanically damaged or compressed due to moisture. All of these situations will reduce its R-value. Adding or repairing insulation to existing walls without damaging the finishes can be a challenging task. The best place to start is your attic due to its accessibility.
Ice Damming on Roof
Ice Dams form on roofs in the winter in cold climates because of inadequate attic insulation. Heat escaping through the ceiling of your home warms the roofs shingles. This heat is translated into melting snow which refreezes as ice when it reaches the cooler part of the lower roof. Ice dams can push up under the shingles and cause water penetration into the attic and eventually your home. The best defense against ice damming is adding additional insulation to the attic space while providing proper air ventilation. The air ventilation will remove moisture from the attic and balance the attic temperature to more closely match the outdoors.
Snow Melt Around Foundation
If there is an even band of snow melt around the exterior of your foundation, your basement is improperly insulated. This is because the heat in your basement is escaping through the walls and melting the snow. If your basement is unfinished, the addition of fiberglass insulation is inexpensive and relatively easy.
High Heating and Cooling Bills
Consult with your neighbors in similarly sized homes about their monthly heating bills in the winter season. If there is a large discrepancy, this is good evidence that there is a failure in your home's insulation systems. Be sure that they use the same furnace fuel type and keep their home close to the same temperature.
Visual Signs of Damaged Insulation
Take a look at the insulation in your home where its visible. Typical areas are attics, unfinished basements or behind electrical outlets. Poor or damaged insulation will be narrow (1 to 2 inches), compressed, wet, have gaps in its coverage and/or not be continuous across the exterior of the home.
Modern homes use and air barrier to trap air in the home like a balloon. This is a continuous plastic sheet that is installed behind the drywall. Older homes were not designed with air barriers and they are nearly impossible to retrofit effectively. Make sure your air barrier is installed on the warm side of the insulation, and make sure the tape securing the barrier is fastened properly.