Properly installed attic insulation is a vital component of any roofing system. Attics that are properly insulated will prevent common roof problems such as ice dams, condensation, and mold growth in the attic. Attic inspections performed by our staff often reveal deficiencies in the roof system due to inadequate amounts of insulation or improperly installed insulation.
The most common problem with attic insulation is found in homes that were constructed prior to 1980. The majority of these homes are under insulated. Here are two simple ways to determine if an attic space needs more insulation:
1. Are the tops of the rafters visible?
If so, the R-Value (a measure of thermal resistance) is too low, and attic insulation should be added.
2. Does snow on the surface of the roof melt before it melts on the ground?
|If so, heat is escaping through the living space and additional attic insulation is needed.|
Our inspectors often find attic insulation that was improperly installed. Below are examples of common mistakes that installers can make.
It is important that roof vents are not obstructed by insulation. In the photo to the right, the blown-in insulation is covering the soffit vents. This prevents proper rooftop ventilation and can lead to a number of problems including ice dams, mold contamination due to high humidity, structural roof damage, and premature shingle failure. Poor ventilation also decreases the energy efficiency of the roofing system by causing an increased load on the cooling system. Insulation baffles are installed to ensure soffit vents are unobstructed.
Attic baffles should be installed to let air from the soffit vents enter the attic space (the air is exhausted at the top of the attic by roof vents). Baffles that are installed incorrectly can allow heat to escape from the living space below. During an Infrared Inspection of the home pictured to the right, heat loss was discovered along the perimeter of the house. An inspection of the attic revealed baffles that were installed too far inward on this house, leaving a small void in the thermal boundary. The heat loss in this case was causing an ice dam and roof leaks. Baffles were reinstalled 2 inches from the soffit vents and the ice dams were repaired without replacing any roofing materials.
Attic doors are often uninsulated. The Infrared photo above is a good example of how inefficient an uninsulated attic door can be. Foam attic door systems are available or an insulated door can be constructed by securing batt insulation to the attic side of the entry.
Unless your home was constructed with energy efficiency in mind, the rim joists were probably insulated incorrectly. Using fiberglass batt insulation at the rim joists is not the best practice. The infrared picture above shows the heat loss associated with this style of installation.
Installing 2″ rigid foam boards at the rim joist opening is an air tight way to insulate this area of a house. The foam can be secured and all air gaps voided with spray foam insulation.
Insulation is measured by its thermal resistance or R-Value. “R” means the resistance to the flow of heat. The Higher the R-Value, the greater the insulating power. The U.S. Department of energy recommends that an attic in the Greater Cincinnati area is insulated to an R-Value of 49. Our installers permanently secure measuring sticks in the attic to ensure the desired amounts of insulation are installed. 18 inches of Owens Corning PINK FIBERGLAS loosefill insulation will achieve R-49.