Attic Insulation in Gaithersburg, MD
Fiberglass Attic Insulation in Northern Virginia and the DC Metro
Many homes in Maryland, Washington D.C. and Virginia were constructed at a time when energy costs were low, and concerns over carbon emissions were unheard of. As a result, many residences have inadequate attic insulation. As utility rates increase, the cost of having insufficient insulation rises as well.
It is also important to consider the other benefits of adding new insulation to your attic. Today’s products also provide beneficial sound, fire and mold-resistance as well.
The Case for Increased Attic Insulation
Several years ago, Boston University researchers led by Dr. Jonathan Levy concluded that approximately nine of 10 U.S. homes are under-insulated. Inadequate attic insulation is often a part of the problem, particularly in homes built before modern insulation standards were established.
The Insulation Institute says, “If your home is more than 10 years old, you likely need more insulation.” In the past, insulation simply filled the gaps between joists. As a result, R-15 to R-21 insulation levels are common in older homes. Since the wood in the rafters is a relatively poor insulator, thermal bridging across the joists further reduces the insulation’s effectiveness.
Suggested R-values vary around the country, from R-30 in warmer areas to R-60 across the northern tier of states. The U.S. Department of Energy divides the country into eight climate zones. Maryland, Washington D.C. and Virginia are in zone 4, where R-49 to R-60 attic insulation is recommended. For many homes, this the “sweet spot” where the added investment in extra insulation is cost-effective long-term.
Overview of Attic Insulation
A reputable, certified contractor is well-positioned to recommend the type of attic insulation that is ideal for your specific situation. In some homes, it is possible to simply add new insulation to the existing insulation. In other residences, it may be necessary to remove old insulation that is either wet and compressed or contaminated by mold or mildew.
There are various kinds of insulation to consider, including batts/rolls, loose fill, rigid foam and spray foam.
Batts and rolls – This type of insulation, usually made of fiberglass, mineral wool or cotton, comes in pre-cut widths that fit between joists with standard spacing. Some batts and rolls include a foil or paper backing that serves as a vapor barrier, while others are non-faced.
Time-consuming cutting is required for attics with lots of irregularly shaped spaces. Some things just can’t be avoided, like exhaust fans and junction boxes. Installation is also difficult in attics with smaller spaces that are tricky to access. Even the most disciplined worker may find it difficult to accurately cut each piece to size. Any gaps compromise the insulating value of the project.
Loose-fill insulation – Fiberglass loose-fill insulation is easier to install than batts or rolls because it readily flows around various obstructions commonly in attics, like ductwork and wiring. It can also be successfully blown into narrow spaces along the outer edge of the attic. Modern fiberglass insulation is manufactured from recycled glass and/or sand that is melted and spun into extremely thin fibers, giving it the consistency of cotton candy.
Potential Energy Savings
How much can you save by adding insulation? Of course, the answer to this question is unique to each home. However, it is worth noting that electricity rates run high in some parts of the Mid-Atlantic. For example, the average 12.84 cents/kwh residential electricity rate in Maryland ranks it 15th in the country.
The government’s Energy Star website says, “Homeowners typically save up to $200 a year in heating and cooling costs by air sealing their homes and adding insulation.” Of course, once an attic is properly insulated with a high R-value product, energy savings accrue year after year.
It is possible to maximize your savings by minimizing air leaks with professional caulking, weather stripping and expanding spray foam. It is also helpful to minimize air leaks around your attic door/hatch and to insulate it as well.
Sealing air leaks also limits moisture intrusion, particularly in the humid conditions encountered during the summer months. Moisture is also generated by activities in the home, like showers and washing clothes. The insulating value of both batts and loose-fill products are quickly compromised when they absorb too much moisture, so proper sealing of cracks and gaps is an important part of the job.
Other Benefits
Although the savings in heating and cooling costs are a major reason to add insulation to your attic, there are other important reasons to do so. Consider the many other benefits of loose-fill fiberglass insulation:
Noise reduction – High-quality loose-fill insulation does an excellent job of absorbing sound. Its superior acoustic performance limits distracting sounds that might otherwise make their way into your home.
Fire resistance – Loose-fill fiberglass and mineral wool insulation are both non-combustible. Since cellulose insulation is made from combustible paper products, it must be treated with large amounts of fire-retardant chemicals like borax nitrate, boric acid and/or ammonium sulfate to meet fire standards. In fact, cellulose insulation is an estimated 15-20 percent fire retardants, by weight.
Moisture resistance – Since the R-value of insulation is quickly compromised when it gets wet, moisture resistance is of utmost importance. Since moisture can be trapped in fibrous insulation like fiberglass, it is important to ensure proper air flow through proper venting. Fortunately, the material possesses excellent air permeability, so moisture will quickly evaporate if provisions are made for good airflow.
Mold resistance – Given the increased awareness of the potentially damaging effects of mold, it should come as no surprise that mold-resistant building products are quickly gaining favor. One of these is loose fiberglass insulation. It is naturally mold resistant, in part because it is non-organic. Mold needs nutrients (organic matter), moisture and certain temperatures to grow. Properly sealed air leaks reduce moisture intrusion. Good air flow further reduces moisture, which more readily evaporates from the spun fiberglass.
Minimize ice dams – As the Insulation Institute notes, an uneven flow of heat into the attic can make ice dams worse. These icy accumulations occur as melting snow on the roof re-freezes as it approaches the colder outer edge of the roof. The resulting ridge of ice is commonly referred to as an ice dam, because it prevents the proper drainage of water. Water backed up behind ice dams can find its way into the sub-roofing, framing and/or interior living spaces. Proper sealing and insulating of your attic space minimize this potentially serious problem.
Less strain on building – Loose-fill fiberglass insulation weighs less than alternatives like cellulose. When you want to achieve high R-60 values, the overall weight of the insulation may be a factor in some residences.
Recycled materials – Although cellulose insulation has traditionally featured more recycled content than its fiberglass counterpart, the latter is posting steady gains in this category. For example, SCS Global Services certifies that Pro Cat fiberglass insulation from Owens Corning averages 55 percent recycled content.
Advantage at resale – It is a good selling point to be able to tell a buyer that you installed R-60 insulation in your attic. A well-insulated home may also be easier to sell because of the lower utility bills you can show a buyer. Also, many prospective buyers understand that a well-insulated roof enhances the comfort of the home’s occupants.
Importance of Proper Installation
