Rockwool insulation can last up to 100 years, but just how long this insulation lasts in your home depends on how well it's maintained. Poorly installed insulation may last only 30 years, so be sure to regularly inspect your home's insulation for water damage, settling, and pests to give your insulation the best chance of having a long lifespan.

Air duct insulation typically lasts for 10 to 15 years or even longer, depending on the material and maintenance. It's important to conduct periodic inspections to check for signs of deterioration, such as water damage, tears, or general wear. If you find any of these issues, it may be time for repairs or a full replacement. You might also consider upgrading your insulation even if it's in good shape to improve your home's energy efficiency and enhance your HVAC system's performance with newer, more effective materials.

Yes, cold walls are a common indicator of poor or inadequate insulation, especially if the walls feel significantly colder than the air in the room. This suggests that heat from your furnace is escaping rather than being retained. The issue could be that the walls have no insulation, or that the existing insulation is old or has been damaged by water, moisture, or pests. Your best course of action is to hire a professional to investigate. An insulation contractor can determine if you need to add or replace insulation and can often perform the work without creating large holes in your drywall. If you suspect the problem might also be related to your heating system's performance, an HVAC technician can take a closer look.

The cost to install a radiant barrier ranges from $700 to $2,800, depending on the size of your roof and the type you choose. Most people pay an average of $1,700 to install a radiant barrier. Foil options, both single- and double-sided, cost between $0.10 and $0.90 per square foot, while spray-on options start at $0.60 and go all the way up to $1 per square foot—which can add up quickly.