Attic insulation can last for a long time, but its energy efficiency benefits can start to decline after 15 years. Certified attic specialists suggest replacing it every 15 years to make sure it continues to perform optimally. If you find a roof leak, it's best to have the insulation in that area professionally inspected. While some types of insulation, such as fiberglass block insulation, are more resistant to moisture than others, such as cellulose insulation, it's only a matter of time before wet insulation becomes moldy.
Replacing attic insulation is one of the most effective ways to improve your home's energy efficiency and comfort levels. It helps keep your home warm in winter and cool in summer. Generally speaking, replacing old insulation may not be worth it if the old insulation is dry, dust-free, and not crushed. Old insulation may be less effective at insulating your home, meaning you won't get the full benefits of the new insulation. Blown insulation products for the attic, such as cellulose, fiberglass, and rock wool, are made of loose fibers and contain air pockets between them.
It's important to keep the attic space well ventilated to prevent moisture from accumulating, and cellulose insulation helps regulate the temperature in the attic. Blown insulation absorbs more water than fiberglass or rock wool, causing it to set faster and lose its R value much faster than other types of insulation. For older homes with dirty or dusty insulation, it's probably time to consider thoroughly cleaning the attic and replacing existing insulation. Removing the old insulation from the attic before adding new insulation will make it easier for you to properly install the new materials, ensure that they are evenly distributed and are effective in keeping the house warm in winter and cool in summer. Pests can also damage attic insulation, so it's important to inspect the attic regularly for signs of infestation.
Older homes may use very old or low-quality insulation, or the insulation may be poorly installed. Ultimately, taking the time to remove old attic insulation before adding new insulation will provide you with several benefits that will improve your home's efficiency.
