Can I Put Too Much Insulation in My Attic?
Insulation is no doubt a good thing as it helps prevent heat from escaping your home. This in turn reduces the demand on our nation’s energy plants.
There are several types of insulation but the most common for attics are fiberglass batts, fiberglass roll, cellulose and spray foam. There are also a few other options for attic insulation, but these four make up the majority of installs.
Fiberglass Batt
Fiberglass batt insulation is usually made of recycled glass and sand. It’s naturally fire-retardant and is effective at reducing outside noises. It can also lower a home’s energy bill by blocking the flow of warm air into an attic. It’s also easy to install and inexpensive, making it a popular choice for homeowners.
However, fiberglass can hold moisture which leads to mold and mildew problems, especially in regions with high humidity. To prevent this, it is important to use a vapor barrier with fiberglass insulation. The barrier is often called “paper backing.” The paper helps repel moisture, which will damage the fiberglass over time and cause it to deteriorate.
Many homes have a fiberglass insulation that was installed in the attic before the house was built. This may be sufficient for the climate in your area, but it probably isn’t ideal for a modern home. To maximize the effectiveness of your home’s insulation, add a second layer of fiberglass batts to the attic. When you do, remember to run the new insulation perpendicular to the old layer. Also, be sure to cover soffit vents to prevent moisture and mold build-up underneath the insulation.
Insulation comes in pre-cut sizes, which makes it relatively easy to install. Depending on the material, you may need to cut around things like electrical boxes and pipes. A utility knife or an insulation cutter can be helpful tools for this task. You can purchase these tools at your local hardware store.
Most home improvement centers rent a blower machine for installing loose-fill fiberglass or cellulose insulation. This type of insulation offers the advantage of a tighter seal and can be more affordable than sprayed foam. However, it’s still a good idea to hire professionals for this job. They’ll know how much insulation your attic needs and how to install it effectively.
A blown-in insulation service will typically include sealing the attic access panel, hatch or fold-back ladder and will insulate the ceiling over it. This will minimize the flow of warm air into an attic and make the existing insulation more efficient.
Fiberglass Roll
When insulating an attic with fiberglass rolls or batts, make sure to install the product properly. Use a tape measure to accurately gauge your attic’s joist width. If the measurement coincides with the width of the fiberglass product, then no cutting is necessary. If the width is too large, cut off the excess with a utility knife or a saw. You can then install the insulation perpendicular to the joists. This will give you the best results, especially if your attic is heated and cooled.
While you’re in the attic, look for air leaks around windows, recessed lights and other penetrations in the ceiling below. Leaving these gaps open lets warm air seep into the attic, which wastes energy and reduces your home’s insulating value. Seal these areas with fire blocking caulk or spray foam.
Before you begin putting in your new insulation, be sure to create a walkway in the attic so you can move around without barricading yourself in. Also, take note of where any soffit vents are located. You don’t want to block these vents, which allow fresh air to flow into the attic and help prevent moisture problems in the living spaces below.
If you have existing insulation in your attic, remove it before installing the new product. This allows you to install more insulation and increases the overall R-value of your attic.
While it may seem counterintuitive to blow more insulation into an attic with old fiberglass, this is actually a good idea. The older insulation is likely to contain large amounts of moisture, which can be a problem in the attic and throughout your home. The moisture can contribute to mold and mildew, and it also interferes with the R-value of your attic.
If you’re able to reinstall the existing fiberglass batts, be sure to use a vapor barrier underneath the insulation to keep moisture from getting into the attic. Otherwise, you should install a wet-spray cellulose insulation instead. This is more expensive than fiberglass, but it has an R-value of 3.6 to 3.7 per inch.
Cellulose
Cellulose is a natural fiber found in plants and other organic matter. It is enmeshed in a polysaccharide matrix that gives plants their structure and supports the walls of plant cells. It also acts as a structural material for some types of wood. It has a high thermal resistance, is water-resistant and fire retardant. It is a common insulation material used in homes and commercial buildings. It can be blown into open attics and enclosed wall cavities, but it is best known for its use in attics. It can be sprayed, poured or stapled into place. It can be used alone or as a top layer of insulating material, such as over existing fiberglass batt insulation.
The most important thing to remember when insulating your home is to get it done correctly. The proper depth and R-value are vital to your home’s energy efficiency. The wrong thickness or R-value can make your home uncomfortable and cost you more in energy costs than it saves. Insulating your attic is an important part of a comprehensive insulation upgrade, but it should be left to professionals who know what they are doing.
It is important to note that not all types of cellulose insulation are created equal. There are two general categories: dry and damp. Dry cellulose is sprayed or blown into open attics and enclosed wall areas, and it is most commonly used in retrofit applications. It can be used in new construction as well. It is often mixed with other insulating materials such as fiberglass or foam board to provide a more complete, energy-efficient installation. It is less expensive than wet cellulose, and it can be used in attics and closed wall cavities as well.
When installing cellulose, it is recommended to follow the manufacturer’s directions to the letter. This will help ensure the longevity of the product and provide the highest level of insulating protection possible.
While cellulose is a more environmentally friendly option than fiberglass, it requires the use of some toxic chemicals in its production process. Those chemicals, including boric acid, are intended to protect the insulation from mold growth and insect infestation. The insulation is then recycled from discarded newspaper and denim, thus helping to reduce the number of trees that are harvested to produce virgin paper.
Mineral Wool
Mineral wool insulation is a type of rock or slag-based insulation also known as rock, stone or slag wool. It's made by heating stone or slag in a furnace until it's molten. This molten material is spun until it cools, creating long thin fibers that are densely packed together. This gives mineral wool its high R-value. It's also environmentally friendly, with 20-30% recycled content.
Another benefit of mineral wool is its fire resistance. It helps keep buildings safe by slowing the spread of fires and giving emergency services more time to respond. It can save lives, money and property, as well as reduce environmental damage.
Like fiberglass, mineral wool is available in blankets and rolls, but it's more common in loose-fill form. It's often easier to install, and it can be used in wall cavities as well as attics. It's usually less expensive than fiberglass and has a better R-value than cellulose.
Blown-in fiberglass, cellulose, spray foam and mineral wool are the four most popular insulation choices for homes. All of these insulation options have a high R-value and can help homeowners save energy, but they all have their own unique benefits and drawbacks.
Choosing the right insulation for your home depends on several factors, including where you live and how much existing insulation is in place. An easy way to see if you have enough insulation is by taking a peek in your attic. If you can see the tops of the ceiling joists, then you need more insulation.
The other factor that impacts how much insulation you need is the amount of air leakage in your home. If you have a lot of air leaks, then you will need more insulation to counteract that extra heat loss.
When adding new insulation, it's a good idea to seal up any cracks and holes in the room ceiling. This will ensure that your newly added insulation is able to deliver the highest possible R-value. For example, a small gap between the bottom of the attic floor and the ceiling joists can let in a lot of warm outside air and significantly reduce the R-value of your new insulation.
Insulation is no doubt a good thing as it helps prevent heat from escaping your home. This in turn reduces the demand on our nation’s energy plants. There are several types of insulation but the most common for attics are fiberglass batts, fiberglass roll, cellulose and spray foam. There are also a few other options…