While there’s several different ways you can go about insulating your crawl space, you want to make sure you do it right. That’s the big key because if you don’t properly insulate the crawl space, you can have more problems than solutions. The same is true when encapsulating your crawl space. In many ways, you can’t have one without the other. If you don’t correctly encapsulate your crawl space and moisture continues to get in, your insulation can fail. And you can have a multitude of issues if both are done improperly.
When we look at the building code, we’re told that your crawl space should be constructed like a mini basement. Crawl spaces should not be vented to the outside. Your crawl space floors should not be insulated. As for your crawl space floor and foundation walls, they should be sealed with a crawl space vapor barrier.
The air in your crawl space must be conditioned. In order to do that, the crawl space must be encapsulated and you’ll need a dehumidifier. Since the dehumidifier will turn vapor air into liquid water, you’ll need a sump pump to extract the water.
If you own a vented crawl space, or called an open crawl space, there’s no question that you’ll have moisture in your crawl space. It’s likely you have insects and pest if foundation vents are left open or you have openings in your crawl space. Before you can add insulation to the crawl space and get rid of your moisture problems, the crawl space must be sealed up.
If you’ll be attempting DIY crawl space insulation, it’s important to note that in order for your insulation to correctly work, the crawl space must be encapsulated.
The proper way to insulate your crawl space is by placing insulation on your foundation walls and adding a high quality vapor barrier to the outside of the moisture. If you’ve read any of my content here at Crawl Space Insulation, you know that I highly recommend Rigid Foam over spray foam. The reason being is the fact that spray foam captures a lot more moisture than Rigid Foam. This can cause your insulation to fail and leave you with quite the mess. Take it from someone who knows, invest in Rigid Foam Insulation to do your crawl space foundation walls.
It’s ok to use fiberglass insulation in your crawl space. We typically use this for floor joist. There’s two important rules to remember with floor joist insulation. First, the fiberglass insulation needs to be clean and dry. It makes no difference which direction you place your fiberglass insulation pieces. Two, never add floor joist insulation before you seal the crawl space. You should only add it after you have encapsulated your crawl space.
All foundation vents need to be sealed. It doesn’t matter if your foundation vents open and close. Closing them is not enough. In order to completely seal your crawl space, you must seal your vents up completely.