The lifespan of attic insulation typically ranges from 10 to 15 years, but its durability can be affected by a variety of factors, such as the weather, ventilation, and pests in your home. If you have cellulose insulation, you may start to feel the effects of it deteriorating as it degrades. Older homes may be using very old or low-quality insulation, or the insulation may have been improperly installed. In this case, you may need to install new fiberglass slats, rigid insulation, or built-in insulation once you've finished roofing. During the warmer months, proper attic insulation and ventilation provide the thermal barrier needed to keep all the warm air in the attic, circulating and out of the living room.
A comprehensive evaluation will provide you with useful information about where your insulation may be failing and what difference a new or modernized insulation can make. If you decide to improve your attic insulation while you're working on the roof replacement project, the next step is to talk to the contractor and decide what type of insulation is right for your specific needs. Fiberglass blocks can start to peel off after 15 to 20 years, so if the insulation was installed in blocks more than a decade ago, it might be time for a home inspection or energy audit. Houses with unfinished attics may not have any type of insulation in the beams, but are instead based on fiberglass blocks or blown insulation installed between the floor beams. Insulating materials can also be damaged by water, contaminated with mold and fungi, or infested by animals that reside in the insulation or use the materials for nesting. Cellulose insulation is environmentally friendly and more effective at blocking air than other types of insulation.
An insulation contractor can inspect the existing insulation and, if it is in good condition, advise you if new insulation can be placed on top of the old one. Spray foam should only be installed when there is no other insulation present.
