We all know that energy costs are skyrocketing with no end in sight. The cost of natural gas for winter heating nearly tripled from January, 2000 to January, 2009 and the cost of air conditioning continues to climb as well. Heating and Cooling accounts for 50%-70% of your energy used in your home. The ceiling in your home is the number one source of winter heat loss and summer heat gain. The good news is, upgrading your attic insulation to reduce your energy costs is comparatively inexpensive and will also minimize ice damming and improve your comfort
Virtually all older homes fall far short of today’s standards and, surprisingly, even new homes in Michigan fail to meet of theDepartment of Energy’s minimum recommendation of R-49 for attic insulation. In fact, most new homes have only R-30 fiberglass insulation with an effective R-value of less than R-20 in the winter!
Most homeowners are surprised to learn that ice dams are the result of heat trapped in the attic. In a poorly insulated home, heat escapes through the ceiling into the attic and without proper ventilation, it remains trapped in the attic. This trapped heat melts accumulated snow on the roof, even though outside temperatures are below freezing. The water from this melted snow travels down the roof until it arrives at the much colder edge of the roof and refreezes forming an ice dam. As the snow continues to melt, additional water pools behind the dam working its way under the shingles and into the attic and wall cavities. While you may see some structural damage, the most extensive damage is often unseen. Moisture in the attic and walls creates a fertile breeding ground for toxic mold, wood rot and insect infestation.
To minimize your home’s exposure to ice dams, you must have adequate insulation in the attic to control heat loss and provide proper ventilation to remove heat and moisture from your attic. Your attic insulation should have an “effective R-value” of at least R-49. Attic ventilation requires a properly sized and balanced system of both intake and exhaust venting. The heat and moisture from bathroom exhaust fans must be vented out of the attic.