After you’ve completed Step 2 which is installing your crawl space vapor barriers, the next step will be installing insulation in the crawl space. We don’t add insulation to the crawl space until the crawl space vapor barriers have been placed on the floors and walls. As you’ll read, there’s two parts to insulating.
Step 3 – Crawl Space Insulation
Once you have your crawl space vapor barriers on the foundation walls and floors, you’re now ready to begin insulating your crawl space. You will need to insulate the band joist and foundation walls.
What Crawl Space Insulation Do You Recommend?
I have a few recommendations in this area as I’ve seen some insulation work great and many others fail due to moisture. Out of everything you can use, I recommend using extruded rigid polystyrene insulation over spray foam insulation. The reason I do is because the spray foam insulation absorbs way to much moisture. The rigid foam works great and will absorb far less moisture, making it the real winner when it comes to insulating an encapsulated crawl space.
Open Crawl Spaces
For those of you that have open crawl space vents, these will need to be completely sealed off for encapsulation. The open crawl space type often contains a lot of issues, from rodents and bugs to environmental conditions, it’s the toughest crawl space type to maintain. With an open crawl space design, you can get environmental changes daily, even every hour. These consistent environmental changes can be a challenge to contend with.
The main purpose of insulating the crawl space is to keep the conditioned air within your home. Yet, this can be a concern as there’s no heating source for the crawl space during the winter months. This causes a concern for those of you that have water pipes in your crawl space. If your heating ducts are in the crawl space, the cold air in the crawl space can cause you to use more energy to heat the home. By properly insulating your crawl space, you can avoid these common issues as well as making your crawl space a healthier place to be.
Crawl Space Encapsulation Guide