While fiberglass is dangerous to work with, it’s a perfectly safe material once it’s installed. If you’re tackling the installation yourself, make sure you take the proper safety precautions and wear the right gear to avoid skin and eye irritation and lung complications. Working with a professional insulation company can mitigate these risks.

Structural insulated panels and rigid foam boards have the highest R-value of any insulation that contractors commonly use, with R-values reaching up to around 8.0. These types of insulation are best in extremely cold climates, but they’re generally preferred for new construction, as they can be challenging to retrofit. Blown-in and loose fill insulation provide the next best insulative value, provided the installation is done properly. It’s important to choose an insulation type that meets your needs based on climate, as maximizing R-value may not always be financially worthwhile if you live in a moderate climate.

Mineral wool wraps are the most affordable and effective insulation for crawl space ducts. They are easy to cut, last for a long time, and healthier for humans. Meanwhile, fiberglass wraps are cheaper but more hazardous and difficult to handle. If you do choose to use a fiberglass wrap, make sure you are wearing long sleeves and wear proper protective gear.

Installing sheets of plywood over attic insulation is a popular choice, especially in storage spaces. That said, insulation works by trapping hot air—so it needs extra space to expand and be effective, or you might reduce the energy efficiency of your home. 

It’s important that you never compress the insulation by installing flooring directly on top of it. In many houses, you’ll need to install a subfloor before putting plywood over insulation in your attic.