As mentioned above, there are three main types of insulation: fiberglass batts, foam boards, and spray foam. Experts will usually choose spray foam as their method of choice.
Here are some benefits of spray foam.
It’s safe for the environment.
It’s Class One Fire Rated (slows down the rate at which it will spread flames, saving your home from burning fast during a fire).
It does not retain water, unlike other insulation types that can absorb moisture.
It creates a stronger air seal than other insulation.
Pest won’t eat spray foam, making it harder for animals and insects to live in your crawl space.
Note: There are two types of spray foam insulation: open-cell and closed-cell. Open-cell spray foam is not completely waterproof and will allow moisture to pass through. Closed-cell spray foam is completely moisture-resistant.
This is where encapsulation comes in. Because closed-cell spray foam is already moisture-resistant and creates an airtight seal, you do not need to encapsulate your crawl space if you use this insulation. If you choose open-cell spray foam, you will need to encapsulate your crawl space in order to seal off air and moisture completely.