Insulation Educational Content
TYPES OF INSULATION
Batts, rolls, and blankets. Fiberglass insulation comes in precut batts, rolls, or blankets. Batts are strips specifically sized to fit between wall studs. They are used during the building process to insulate walls before drywall is hung. Fiberglass rolls can be rolled out on attic floors. Blankets are common for insulating basement or crawl space ceilings. If you’re looking for an eco-friendly insulation product, look into mineral wool insulation. It is also available in blankets. Mineral wool is on the higher end of the cost scale, so it’s typically used sparingly. You’ll often find it around chimneys, for example, where a fire retardant is a smart choice.
Loose fill. Loose fill is convenient for insulation contractors to use in attics because it can be blown in. Cellulose and fiberglass are the most popular loose fill materials, and they both have pros and cons. Ask your insulation contractor for product recommendations based on your home and budget. Loose fill insulation is installed by blowing it into the space using a large hose. In most cases, the installation crew has a truck-mounted machine for this process. The result is an even blanket of loose fill insulation. One advantage of loose fill is that it is easily installed around pipes and in empty wall cavities. It can also go on top of existing insulation. Loose fill insulation should be blown in by a professional. The pros know precisely how dense the layer of fill should be to maximize its insulating ability.
Foam insulation. Foam insulation is a dense material. In fact, closed-cell foam insulation has the highest R-value of all insulation types. Various forms of foam insulation can be used in all areas of your house. Foam insulation comes in both expanding and nonexpanding varieties. It can easily fill irregular spaces. Nontoxic and soy versions are also available. Foam insulation is usually classified as either open-cell or closed-cell. Closed-cell foam is rigid and has a higher R-value than open-cell foam. It costs significantly more than open-cell foam. Closed-cell foam stops moisture vapors and is highly mold resistant. This makes it preferable for damp areas like crawl spaces. Open-cell foam is also highly efficient, but it doesn’t stop moisture vapor the way closed-cell foam does. It is, however, less expensive. The initial cost of foam insulation is typically higher than other types of insulation. The energy savings you’ll see over time can recoup the higher up-front cost.
Foam insulation can be broken down further by installation type. Spray foam is common in new construction, where it is sprayed into open cavities during the building process. Pourable versions can be used in existing structures. If too much is installed, however, pourable foam can crack drywall as it dries and expands. Injection foam is often used as a retrofit solution for existing structures. Injection foam is injected into wall cavities via small holes. It does not expand during installation, which reduces the chance of drywall damage. Spray foam and injection foam perform similarly once installed.
Cellulose. With increased demand for green construction in the US, cellulose insulation is growing in popularity. Cellulose insulation is a loose-fill material made from paper mixed with flame retardants. It works great as an insulation upgrade in older homes. Cellulose insulation is blown into spaces like its fiberglass counterpart. As a bonus, many brands of cellulose insulation are treated with pest-deterring borates.
Radiant barriers. Radiant barriers are foils or films that are engineered to reflect radiant heat toward the heat source. Radiant barriers can be installed in several areas in a house but are often used in the attic. In an attic, the radiant barrier is attached to the underside of the roof rafters.
An insulation’s R-value is a measure of its thermal resistance to heat flow. The higher the R-value, the more effective the insulation. The more effective the insulation, the less heat that transfers in and out of that area of the house. Each wall and ceiling in the home, as well as any crawl spaces, may have a different R-value. Some insulation brands offer a greater R-value per inch of thickness than others. This is because of density and other product differences.
Air sealing is the process of finding and sealing the spaces in a house that let air escape. It’s an energy-saving complement to an insulation upgrade. A blower door test is a good way to identify areas of air leakage. A common air sealing technique is to install or replace weatherstripping and caulking around the house. The crew will also check pipe seals and gaskets and fix them if needed. Your contractor will have a range of solutions depending on your home’s needs. The air sealing process typically results in lower utility bills.
SIGNS OF POOR INSULATION
It can be hard to know for sure whether your house has enough insulation. Unless they’ve been extensively renovated, most older homes do not have enough insulation. Keep in mind these signs of inadequate insulation:
High utility bills. When a house is poorly sealed or inadequately insulated, air escapes through any small opening. This means that the HVAC system will run more often. As a result, the HVAC system may not work efficiently for its full lifespan, which equals more energy use and higher utility bills.
Ice dams. A house that doesn’t have enough insulation will lose a lot of heat in the winter through the roof. The warm air melts snow on the roof, which then refreezes at the edge of the roof, causing ice dams and icicles. Ice dams are harmful because they can damage shingles and gutters and cause roof leaks.
Dusty rooms. A lesser known symptom of inadequate insulation is poor indoor air quality. Small gaps around the house can allow too much air to flow in and out. This can cause the house to be dustier than normal.
Hot and cold spots. Uneven temperatures and humidity levels throughout the house can signal inadequate insulation. Uninsulated spaces and poor-quality fiberglass insulation are common causes of these problems. An insulation contractor will be able to recommend possible solutions.