Insulation can last for decades if it’s properly maintained. Regular inspections for visible damage, moisture build-up, and critter infiltration can help prevent deterioration and ensure that your home is well protected.
Different types of insulation have different lifespans. Learn more about the typical lifespan of each type and the telltale signs that it’s time for a replacement.
Fiberglass
Often the default choice for insulation, fiberglass has a lifespan between 80 and 100 years. However, this is with perfect conditions and without complications such as rodent activity, moisture, or air movement which can degrade the insulation. In general, you should replace fiberglass insulation when you see signs of rodent or insect infestation, if it becomes dirty or wet and loses its insulating properties or if your energy bills have risen for no apparent reason.
Fiberglass is made from a variety of materials, including soda ash, alumina, borax, and silica. These raw materials are all obtained through mining (often using geothermal, mechanical, or chemical energy) and require extensive transport to reach the factory. Often, recycled glass material is used in fiberglass to help reduce the amount of raw materials required for the manufacturing process.
Once in the factory, these raw materials are dry mixed before being melted in a centrifuge technique to create strands of glass that are then spun into a loose-fill fiberglass insulation product. This fiberglass is then blown into a wall or attic space, rolled into a batt, or used in open framing situations on new construction sites and can also be layered with other insulation products such as mineral wool.
Cellulose
Cellulose insulation is another green material made primarily from recycled paper. It is often considered one of the most environmentally friendly types of home insulation on the market. Cellulose can last up to 30 years, though it may begin to degrade around the 15-year mark if not properly maintained.
This type of insulation is typically installed in existing homes in a blanket (batts or rolls) form, but it can also be wet sprayed into new construction walls and attic floors. It is a more flexible insulation and can fit tight spaces between walls or behind ductwork better than fiberglass batts. Wet spray cellulose is treated with borate compounds to prevent mold and pest growth as well as fire resistance.
Like fiberglass, cellulose is an effective air-blocking insulation that provides R-value of up to 3.5 per inch of thickness. It is hygroscopic, which means it absorbs moisture in the air. However, this moisture is dispersed throughout the insulating material so that it doesn’t settle in one area or promote mold growth.
Fiberglass batt insulation, on the other hand, is prone to falling down, becoming water-logged and moldy in crawl space ceilings, and being stained by rodent feces in stud walls. In general, fiberglass insulation will need to be replaced within 10 years or so if it’s in a wet area or is already beginning to degrade due to age.
Mineral Wool
Mineral wool insulation is a highly durable material that can last for decades. It can withstand many types of weather, including extreme temperature changes. It also resists pests and moisture, which can extend its lifespan. However, it’s important to regularly inspect your insulation for signs of damage and pest activity. If you spot any problems, it’s best to address them right away to avoid costly repairs or replacements.
It’s made from recycled materials, which means it has a lower carbon footprint than fiberglass. Additionally, it is not flammable and does not release toxic fumes during a fire. It’s a great option for builders who are concerned about their environmental impact, or for those who want to reduce their exposure to formaldehyde.
Manufacturers use a variety of techniques to make stone wool, but all produce a mass of intertwined fibers that are bonded with a binder, usually a terpolymer. The product is then cured to ensure strength and durability. It can be cut and shaped into different forms, including batts, blankets, and boards.
It can be installed in place of fiberglass batts, and it has a high R-value. It also has a low vapor permeance rating, which can improve air quality in buildings. It is also non-combustible, which can protect against the spread of fires within framing cavities and prevent the buildup of toxic smoke.
Spray Foam
The lifespan of spray foam insulation is often longer than other insulation materials, and this makes it a great option for homeowners who are looking to upgrade their homes. This is because it keeps hot air out in the summer and cold air out in the winter, resulting in lower energy bills all year round. It also increases the value of your home and helps to reduce carbon emissions, which is an important factor in preserving our environment.
Spray foam is made from a polymer, which means it contains many molecules strung together to form a durable material. It is an insulator because the material traps air bubbles within its walls, slowing the transfer of heat. It is available in two different types, open or closed, and the type that is best suited for your home depends on your needs and the environment where it will be used.
Closed cell spray foam is more rigid and dense than its open-cell counterpart, making it the better choice for areas that require a moisture barrier, such as attics or basements. It also comes with a fire retardant. Open-cell spray foam is more flexible and cost-effective, but it does not provide as much thermal protection as closed-cell spray foam.
It is recommended that you hire a professional to apply spray foam insulation, as mistakes during the application process can greatly shorten its lifespan. A certified professional will know what equipment to use and how to properly prepare the space for application. They will also be familiar with the requirements of your area’s building codes. This is particularly important if you are considering getting rebates or tax credits for improving your home’s energy efficiency.