The time required for insulation installation can range from a few hours to a few days, with most projects taking 1-3 days to complete. The final duration depends on the project's size and complexity, the area size, and the type of insulation being installed.

Blown-in insulation works, but only for unfinished attics. Also, it isn’t the longest-lasting nor the most effective option. For better options, look into spray foam insulation or natural fiber batts. They typically have a longer lifespan, better heat resistance, and stronger sound-proof abilities. Spray foam insulation costs about $1.25 to $1.50 per square foot, but can go up to more than $4 per square foot. Fiber batt pricing varies depending on the material.

One of the clearest signs that your insulation isn’t working as well as it should be is a noticeable difference in temperature throughout your home. One room might feel icy while another is hot as Arizona—this indicates that some parts of your home are either retaining or losing heat more than others. Additionally, a sudden increase in your energy bills, evidence of pests or rodents, or evident water damage are other signals that warrant a thorough inspection of your insulation and potential replacement.

The best type of attic insulation depends on where you live, your budget, and what stage of construction the attic is in. For example, if you're building a house, then structural insulated panels are a worthy investment since they're easy to install during construction and they're the most energy-efficient type of insulation.  

Additionally, if you live in a very warm climate, then you can potentially save quite a bit of money by opting for reflective insulation, which is more affordable than comprehensive insulation but doesn't work well for cool climates. Blown-in, loose-fill, and spray foam insulation are all great options for attics in moderate climates.