Home insulation is a great way to reduce energy costs and create a comfortable, eco-friendly environment. However, not all insulation is created equal.
There are four common types of insulation that can be used in homes: fiberglass, mineral wool, cellulose, and spray foam. Each has its own pros and cons, as well as varying R-values.
Fiberglass
Fiberglass is the most popular form of home insulation. It is made from spun glass fibers, and it is available in blanket or roll form (called batts) as well as in a blown-in type that you can use in attics. It is the most affordable option and is easy to install for DIY homeowners. It is also Class 1 fire rated, meaning it doesn’t serve as a fuel source in the event of a house fire.
It works by trapping air bubbles and slowing the transfer of heat, making it an effective thermal insulator. It comes in different thicknesses that determine the R-value, with higher R-values offering more insulative properties. Fiberglass is an environmentally friendly insulation option, and it doesn’t contain any hazardous chemicals. However, it can be a lung and skin irritant, and you should always wear protective clothing when handling it.
Its only real drawback is that it doesn’t block the movement of air – and this is what really matters when it comes to a home’s energy efficiency. Even if your walls are well insulated, outdoor air will still enter your home through gaps and cracks. The more air that is moving around your home, the more energy you will waste on heating and cooling it. This is why it’s important to choose an insulator with good air sealing qualities.
Cellulose
Cellulose is a type of insulation that is typically blow-in, meaning it is applied by an experienced professional rather than being cut and placed in walls. It is more expensive than fiberglass, but it is environmentally friendly, and many professionals consider it safer.
It has a higher R-value than fiberglass batt insulation, which means that it resists heat flow better. It is also more effective at reducing noise transmission than other types of insulation, particularly in new construction homes. Blown cellulose insulation is also known as low-dust insulation, which can be helpful for homeowners who suffer from allergies.
Cellulose insulation is made from recycled paper products, which means that it has a very high post consumer recycled content. This makes it a green option for eco-friendly homeowners. It can also be a good choice for homes with moisture concerns, as it is resistant to mold and mildew growth.
It is treated with ammonium sulfate and boric acid to meet governmental fire safety requirements. This treatment, as well as the fact that it is tightly packed, prevents the spread of fire between framing members. This gives it a class 1 fire rating. It also has a lower embodied energy than mineral wool, which requires 20 to 40 times more energy to produce in furnaces than cellulose does. In addition, it is manufactured locally, while mineral wool insulation must be shipped long distances.
Mineral Wool
This is a fibrous insulation that can come in several forms, such as rock wool (made from basalt), glass wool (made from recycled glass) and slag wool (produced by burning metal shavings at high heat to create a slag material). All types of mineral wool are non-combustible.
It’s available in batts and blown-in forms, making it an option for DIYers. It has a higher R-value per inch than fiberglass, and it is also made with more than 70% recycled materials. It can be used in walls, ceilings and floors in new construction and retrofits.
As an insulator, mineral wool is more resilient than many other materials. It doesn’t lose its shape over time, as fiberglass or cellulose insulation can do. It isn’t easily damaged by water or moisture, and it doesn’t provide a food source for microorganisms that can lead to mold or mildew.
Mineral wool is a good choice for building owners looking for a long-term solution for their home. It has an average life expectancy of 55 years and is extremely durable. It is often part of an External Thermal Insulation Composite System, or ETICS, in commercial and multifamily residential projects. Unlike other types of insulation, mineral wool can be perforated and cut without losing its thermal resistance. It can also be installed in a variety of ways, including exposed-keel suspended installations and composite pasting.
Spray Foam
There are two types of spray foam insulation: open and closed. Both offer excellent energy efficiency and can dramatically reduce your home heating and cooling costs. Closed-cell spray foam is a little more expensive than open foam, but it offers higher R-values and can seal small gaps between joists better.
The insulating value of foam depends on the material from which it is made and how it is installed. For instance, fiberglass batting is inexpensive and easy to install, but it doesn’t provide the R-value of other insulation. It also isn’t a good choice for homes with moisture problems since it can attract and hold water.
Closed-cell polyurethane spray insulation offers a high R-value, can be sealed to prevent air and moisture penetration and provides a strong thermal barrier. This type of spray insulation is a more durable option and can last up to 80 years.
Blown-in cellulose is made from recycled newspaper and is eco-friendly. However, it is dusty to install and is susceptible to mold growth and moisture absorption.
Mineral wool insulation is another option that is environmentally friendly, but it’s not as cost-effective as fiberglass batt insulation and doesn’t have the R-value of other options. It can still improve your home’s energy efficiency, but only if it’s applied properly with a tight seal.