The Importance of Insulating Your Crawl Space
Turn crawl spaces into a more useful part of your home
Crawl spaces seem like a dark, damp dungeon, but they’re a basement alternative that can help you slay dragons you didn’t know you were battling. Crawl spaces provide storage when your household items have grown beyond closets and cabinets. They help hide plumbing and wiring that often take away from the aesthetically pleasing look of your home.
Crawl spaces act as a buffer between your house and the cold, wet ground. And because of their proximity to the ground and outside, it leaves your home susceptible to air drafts and moisture. Instead of dealing with discomfort, high energy bills, and mold, let’s talk about why insulating your crawl space should be on your list of DIY projects.
Understanding Crawl Space Insulation
It’s a hollow, narrow area—think hands and knees height—that works as a buffer between your home’s first floor and the ground. It also provides easy access to your wiring and plumbing systems. While some people consider it a basement, crawl spaces are smaller, unheated, and unlivable.
But that doesn’t mean they’re unusable. In fact, crawl spaces can make a drastic difference to your home when insulated.
Typical Characteristics of a Crawl Space
Like most rooms, crawl space foundations will change from house to house, but there are a few features you can almost guarantee. Usually, crawl spaces are:
About four feet tall
Made of concrete block walls
Have dirt or concrete slab floors
Unfinished
From this list alone, crawl space and basement foundations share certain characteristics, but there are many differences.
Difference Between Basements and Crawl Spaces
Some homeowners think of their crawl space as a basement, and while there are noted similarities, both spaces are more different than they are alike. Basements and crawl spaces are types of foundations where the perimeter is made of concrete walls, making the spaces durable against damage. And that’s where the similarities end. You’ll find that basements and crawl spaces differ in size, appearance, cost, and value.
Crawl spaces are shallow areas that don’t have enough room to stand up in—unless you’re less than four feet tall—so you’ll need to crawl. Basements are significantly deeper with ceilings that are usually seven to 10 feet away from the floor. Because of their size differences, crawl spaces are easier and quicker to install.
With crawl spaces, you may not have an actual floor. They commonly have floors made of concrete—just like basements—but they can also have dirt floors which are far from aesthetically pleasing.
On average, basements are more than double the cost of crawl spaces, but they offer more value to your home. Both foundations provide easy access to utilities and leave room for storage, but basements are typically finished, making the space more useful and inhabitable. When it comes time to sell, this translates to more money in your pocket.
Benefits of Crawl Space Insulation
How can adding insulation to this dark, dingy space be beneficial? Crawl space insulation helps to keep your belongings and space safe from floods. It does so by providing thermal insulation, keeping your home energy-efficient, and preventing your pipes from freezing in the winter. Insulation also helps protect the crawl space by waterproofing against light to moderate precipitation.
Here are some more pros of crawl space insulation.
Increases Energy Efficiency
When your crawl space isn’t insulated, the home uses more energy than necessary to heat up or cool off your home. Just like your attic, even if you don’t frequently visit your crawl space, it’s still attached to your house and impacts your internal temperature and—by default—your energy efficiency.
By insulating your crawl space, you’ll seal it up from being affected by the temperature outdoors, which will help your home feel way more comfortable.
No Pests
A crawl space provides the perfect shelter for most pests: It’s dark, damp, and out of the elements. There’s nothing worse than having unwelcomed house guests take over your crawl space—except if those pests move into your living space.
By insulating your crawl space with a durable insulation type, you can keep critters out of your space and away from you and your home.
Added Storage
Extra storage space has loads of benefits for the average homeowner. And while a crawl space can be the answer to most of your storage needs, it can do more harm than good if it isn’t insulated. Insulate the foundation so you can place your belongings in a safe place that will keep them protected while being out of sight. Win-win, anyone?
Improves Air Quality
Crawl spaces let unfiltered air into your home. Insulation can reduce pollutants entering your home and help increase indoor air quality.
Types of Insulation Used in Crawl Spaces
Let’s take a quick look at the different types of crawl space insulation.
Fiberglass Batts
They’re a thick blanket made from reinforced plastic and fine-glass fibers. They’re placed between the exposed joists when used in crawl spaces and cost $0.30 to $1.50 per square foot, making it the least expensive option for crawl spaces. However, they attract moisture that can lead to mold and may make a cozy nest for pests. Fiberglass batts also start losing their effectiveness in 15 years.
Spray Foam
This type is a liquid latex or polyurethane foam that expands and hardens to fill gaps within its path. Once spray foam dries, it forms a solid protective layer against unwanted animals and weather. And unlike fiberglass, it doesn’t hold moisture, isn’t appealing to pests, and creates an air seal in your crawl space. It can last up to 80 years. Spray foam insulation costs $0.50 to $2 per square foot.
Foam Board
Foam board insulation is a rigid panel installed against the walls of the crawl space. Like spray foam insulation, it stays where you place it, doesn’t absorb moisture or let air in, and doesn’t provide a food supply for animals. Foam board insulation also lasts for more than 100 years. On average, you’ll pay $0.25 to $1 per square foot.
How To Insulate a Crawl Space: DIY vs. Hiring a Pro
DIY Process
Before learning how to insulate a crawl space, you need to identify the parts of its structure that you’ll either need to work around or insulate. Crawl spaces usually feature support structures—foundation walls, beams, and piers—as well as joists and access entries. To insulate your space, you’ll need to:
Check building codes
Check your home’s foundation
Remove standing water
Encapsulate crawl space against air and moisture
Insulate walls
Insulate rim joists
Install a floor vapor barrier
When to Call A Professional
Insulating a crawl space is a DIY-friendly project for most homeowners, but there are levels to it. If you plan to do the job yourself, you’ll need to stick to rigid foam insulation. It’s a less expensive option, and while it has a high R-value (the insulation’s thermal resistance measurement), it’s not as high as other alternatives like spray foam or blown-in insulations.
While there are problems with spray foam insulation, it has a very high R-value. Spray foam and blown-in insulations are perfect for filling in tight and hard-to-reach spaces. But if you want to insulate your crawl space with them, you’ll need to call in a local insulation professional. The installation requires more equipment, experience, and expertise than the average homeowner has.
Crawl Space Insulation Costs
The total cost you can expect to pay from insulating your crawl space varies considerably based on the insulation material, R-value, the crawl space size, whether it’s vented or unvented, and its existing condition.
Since most insulation projects are fairly straightforward, you can DIY them with time, patience, and knowledge. DIY insulation projects cost up to $500.
But if you aren’t comfortable with the time and skills needed to do it on your own, an insulation contractor near you may charge $1,500 to $6,900 to complete this project.
Is Crawl Space Insulation Worth It?
The cost of Insulating your crawl space is temporary, but it’s an investment you’ll feel year-round. Not only will it make your home more comfortable and cut down on moisture, pollutants, and pests, but it’ll also help you save on energy costs. The Environmental Protection Agency estimates that by insulating crawl spaces—as well as attics and floors—homeowners can save an average of 15% on HVAC costs.
Frequently Asked Questions
Three signs that you need crawl space insulation are drafts, high energy bills, and mold. Drafts can start in crawl spaces and cause hot or cold air to spread to the rest of your home through holes in the floors and walls. And even if your entire home is well-insulated, you can still feel an unchecked draft from your crawl space and in your utility bill. Uninsulated crawl spaces can let in air and moisture, and because they’re built directly on the ground and difficult to dry out, they are hotspots for mold and mildew.
While the answer may depend on who you ask, most contractors would agree that spray foam insulation is a strong candidate for this job as it is effective at repelling moisture and is resistant to biological growth.