Why Attic Insulation?
Heat moves through materials. Different materials have different resistances to the transfer of heat. While heat can move easily through metal, there are other materials that heat cannot move very readily through. These are the materials used for attic insulation.
Heat will move out of a house in the winter by traveling through uninsulated places such as the attic. Your furnace will warm up your house in the winter. But if you don’t have adequate (or any) attic insulation, that heat travels up through the ceiling and escapes out of the roof. The same mechanism works in the summer. Your air conditioning system cools your house. The summer heat comes in through the roof and, if your attic is poorly insulated, will travel through the ceiling into your home.
There are some things that can make your insulation perform poorly. For instance, voids in the insulated space (places where there is no insulation) allow an easy escape for heat. A common void in attics is the space where an attic stairway or access panel is inserted in the ceiling. If there is no insulation attached to the opposite side of that panel, then this area is a quick escape for heat. Compression of the insulation decreases its effectiveness since the dead air space between the insulation fibers is eliminated. This dead air space aids in the resistance of heat transfer. Without it, the heat can transfer through the material quicker and escape. Compression of insulation can happen over time. It can also compress when anyone steps on it or sets an object on it. Also, the entire space the insulation is in should be air sealed. The dead air spaces only work if the air is still. If there is air movement through the insulation, the moving air will take the heat with it. Insulation must also be kept dry or it will lose heat resistance. Roof leaks will cause the insulation to settle and compress.
Image: U.S. Department of Energy
The heat resistance of insulation, or ability of heat to move through the insulation, is described using a number called R-value. The R-value is a function of type of insulation, thickness of the insulation, and density of the insulation. According to this map from the U.S. Department of Energy, attic insulation in the Denver area, which is Zone 5 on the map, should be between R-49 and R-60. R-values are cumulative. If your attic insulation is already, for example, R-38, you can have more insulation added to bring it up to R-49 or greater.
Types of Insulation
Attic insulation comes in several types. Foam board or rigid foam insulation is made of polystyrene, polyisocyanurate, and/or polyurethane. It is good for unfinished walls, including foundation walls, floors and ceilings, and unvented low-slope roofs. It has a high insulting value for a relatively low thickness. It can block thermal short circuits when installed continuously over frames or joists. Traditional loose-fill and blown-in insulation is made of cellulose, fiberglass, and/or mineral (rock or slag) wool. It is good for enclosed existing wall or open new wall cavities, unfinished attic floors, and other hard-to-reach places. It is good for adding insulation to existing finished areas, irregularly shaped areas, and around obstructions. Peak to Peak uses Owen Corning ProCat blown-in insulation. It is an upgraded version of blown-in insulation that is made with more than 65% recycled glass. Spray foam and foamed-in-place insulation is made from cementitious, phenolic, polyisocyanurate, and/or polyurethane. It is good for enclosed existing walls, open new wall cavities, and unfinished attic floors. It is good for adding insulation to existing unfinished areas, irregularly shaped areas, and around obstructions.
Peak to Peak Roofing and Exteriors Installs Denver Attic Insulation
If your attic in the Denver metro area needs more insulation, Peak to Peak Roofing and Exteriors can help. We install Owens Corning ProCat High Performance Loosefill insulation. This is a blown-in insulation that can be applied to unfinished attics as well as on top of existing attic insulation. With ProCat there is no settling of the insulation so the R-value will not decrease over time. It is noncombustible, will not absorb moisture, does not support mold growth, and is pest resistant. ProCat is made with recycled glass and does not out-gas once installed in your attic. It is certified by SCS Global Services to contain an average of 55% recycled glass content, 18% pre-consumer and 37% post-consumer. It is also certified to meet indoor air quality standards under the stringent GREENGUARD Indoor Air Quality Certification Program and the GREENGUARD Gold Certification. This product has a limited lifetime warranty on its performance. This is combined with Peak to Peak’s two-year workmanship warranty. Together you have peace of mind and a home that is warmer in the winter and cooler in the summer. Call us today for a free consultation.