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Crawl Space Insulation: Virginia’s Ultimate Guide

No one looks forward to getting out of bed and stepping on ice-cold floors.  

While Virginia winters aren’t especially long, temperatures in Chester can get as low as 29°F in January. 

Your home can be chilly if it isn’t prepared.  

In this article, learn how proper crawl space insulation saves you money and makes your home more comfortable.  

What Can Damage Your Insulation?

When you think of a typical “nasty” crawl space, the image you conjure up often involves hanging, moldy fiberglass insulation. 

This type of insulation was probably installed by your builder at the time your home was constructed. Given the high humidity in Virginia, it doesn’t take long for it to do more harm than good. 

As you can see pictured here, typical hardware store fiberglass insulation sucks up water and water vapor, making it the perfect breeding ground for mold and mildew. It’s also a great home for rodents and pests.  

Removing this insulation is the only way to get rid of the problem. 

Insulating a Crawl Space

Today we know a lot more about crawl spaces and understand that any organic material can be damaged if the crawl space isn’t properly sealed.  

Encapsulation involves insulating the crawl space walls and sealing the floor from outside air and water.  

Wall insulation board installed without sealing the floor will provide little benefit as conditioned air will escape through the untreated dirt floor

Each home is unique, and never has this been truer than in Virginia. When considering crawl space insulation, a plan should be designed to best meet the needs of the specific crawl space. 

Still, here are the general steps for crawl space insulation: 

1. Clean & Remove Old Insulation

Before work can begin, it’s best to clean the crawl space of old building materials and trash. Existing damaged insulation should be bagged and removed. 

Cleaning and insulation removal is a step homeowners can take before calling professionals. However, it’s a filthy, dangerous job. Remember to wear gloves, a face mask, and eye covers.  

2. Install Drainage

This step is where the experts should be involved. Almost all homes require some type of drainage. For you, it may mean a sump pump, for others, drainage matting, or a crawl space drain.  

A crawl space inspector will do a full assessment inside and outside of your home to determine the best solution. 

3. Seal Vents

While vents were originally thought to be helpful, we now know that isn’t the case.  

Building America researched crawl spaces and found unvented crawl spaces use 15% to 18% less energy and reduce humidity by 20%.  

Because of this data, the next step is to seal any existing vents with airtight material. 

4. Select Wall Insulation

JES recommends rigid closed-cell foam board insulation with an R rating of at least 10. The board should also have a radiant barrier, meaning it reflects heat into the crawl space.  

5. Install Boards

Insulation panels should be installed on the walls using a mechanical fastener. Building code requires an opening near the top of the wall to check for termite activity. 

Since each city is different regarding requirements, it’s best to work with a company that has years of experience. 

6. Finish Encapsulation

With the insulation complete, the rest of the encapsulation project can be finished.  

While this will look different for each home, it typically involves a vapor barrier on the floor, structural support, if needed, and an air system.  

How Insulation Protects Your Crawl Space

While insulating your crawl space is just part of the encapsulation process, it is a very important part. 

Insulation regulates the temperature throughout your home, making it feel warmer in the winter and cooler in the summer. This translates to lower energy bills year-round. 

Keeping the space beneath your home warm also means your floors stay warmer during Virginia’s chilly winters. 

One of the biggest advantages, however, is frozen pipe prevention. Warming the area means your pipes are less likely to freeze, saving you a big headache.

Crawl Space Insulation with JES

JES has been transforming homeowners crawl spaces since 1993. Working with JES means you’ll get professional repairs and quality customer service.  

If you’re looking to install insulation in your crawl space, don’t hesitate to contact us today. We’ll make sure your home stays protected for years.  


Selecting the right insulation for a crawl space is unique to any other area of your home. Look for a ridged, closed-cell foam that provides a thermal barrier and has at least an R-10 value.

Absolutely. Insulating your crawl space saves money by creating a warmer and more even temperature both in the crawl space and the living area of your home.  

Insulating the floor over your crawl space isn’t necessary if the crawl space is properly encapsulated. Insulation on the walls and a vapor barrier on the floor seal out outside air, keeping the temperature stable.  

Adding insulation to the floor would only increase the cost.

JES Can Help Encapsulate
Your Crawl Space

Our team at JES Foundation Repair is proud to serve homeowners in locations throughout Virginia, including: 

  • Charlottesville 
  • Chesapeake 
  • Fredericksburg 
  • Hampton 

Don’t see your service area? Check here.

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