Encapsulation will prevent critters and moisture from entering your home. Don't let it get this bad.
You can see here that the wood over time has broken down and is causing major structural problems in a home.
Many of times homeowners say, "My home isn't that bad." Then we go under their home and this is what we see. Don't ignore sagging floors and neglect your crawl space. It is just as important as the rest of your home!
The insulation here is doing nothing for this homeowner, except providing shelter to critter, pest and moisture. Moisture in your crawl space can ruin your insulation, making your home inefficient.
Mositure and wood are never a good thing under the home. You can't take away the wood under your home but you can fix the moisture. Check out these pictures of what can happen to wood when mositure in your crawl space becomes a problem.