Everything You Need to Know About Crawl Space Encapsulation
by Ted Dryce | July 12, 2024
Crawl space encapsulation is critical for homeowners looking to improve their homes’ health, energy efficiency, and overall value. This guide provides a comprehensive overview of crawl space encapsulation, its benefits, potential drawbacks, and whether it’s the right choice for your home.
- What is Crawl Space Encapsulation?
- Is Crawl Space Encapsulation a Good Idea?
- When Should You Not Encapsulate a Crawl Space?
- Alternatives to Crawl Space Encapsulation
- Crawl Space Encapsulation Cost
- Is it Worth it to Encapsulate a Crawl Space?
- Materials Needed to Encapsulate a Crawl Space
- How to Encapsulate a Crawl Space
What is Crawl Space Encapsulation?
Crawl space encapsulation involves sealing your crawl space to prevent moisture from entering. This process typically includes insulating the walls and floor, sealing vents, and installing a dehumidifier to maintain a dry environment.
The goal is to create a clean, dry space protected from the elements. If possible, it’s a good idea to inspect your crawl space to determine what might need repairing. To help you get started, we’ve prepared a helpful checklist that can serve as a jumping-off point for identifying any issues.
Encapsulated vs. Sealed Crawl Space
While both encapsulation and sealing aim to control moisture, encapsulation involves a more thorough process. Sealing usually refers to closing off vents and minor leaks, while encapsulation includes adding a vapor barrier and additional insulation for comprehensive protection.
Crawl Space Encapsulation vs. Vapor Barrier
A vapor barrier is a component of encapsulation but not the entirety of the process. In many homes, you might see a vapor barrier laid only on the ground of a crawl space. Laying a vapor barrier on the ground will prevent moisture from the soil from getting into your crawl space, but encapsulation includes the installation of a vapor barrier on the crawl space walls. Other measures are also taken in the encapsulation process to ensure long-term moisture control and improved air quality.
Is Crawl Space Encapsulation a Good Idea?
For many homeowners, encapsulating a crawl space is a wise investment. It protects the home from moisture-related issues and enhances energy efficiency, leading to lower utility bills.
Benefits of Crawl Space Encapsulation
There are several benefits of crawl space encapsulation including:
Mold Prevention
One of the significant benefits of crawl space encapsulation is its ability to prevent mold growth. By controlling moisture levels, encapsulation creates an environment where mold and mildew cannot thrive. Mold can be more dangerous than you may think. If left to fester can spread to other areas of your home, causing health issues. You can prevent this by sealing out external moisture and moderating humidity levels with a dehumidifier.
Improved Air Quality
Several things can affect air quality, but a few notable ones are:
- Airborne allergens (pollen and mold, notably)
- Ozone pollution (from cars and other emissions)
- Particle pollution (from wildfires)
Poor air quality can aggravate pre-existing issues like asthma and allergies. Guess what? An encapsulated crawl space helps keep those elements out of your home by preventing them from entering your crawl space.
Prevention of Structural Crawl Space Damage
Since most crawl spaces have wooden structures, they’re susceptible to damage from water.
A humid and moist crawl space or regular flooding can cause the wood structures in your home to deteriorate.
When wooden floor joists start to bend and warp, the safety of your home is at stake. Encapsulation prevents crawl space moisture and helps prevent structural issues from worsening.
Longevity of Encapsulation
When done correctly, crawl space encapsulation can last many years.
The materials used are designed to withstand the test of time, providing ongoing protection and peace of mind. Plus, if your crawl space contractor has a warranty, the encapsulation can be maintained for longer with a lower maintenance cost.
Ready to encapsulate your crawl space?
Negatives to Crawl Space Encapsulation
Despite the benefits, there are some downsides to consider. A few negatives to crawl space encapsulation are the high initial cost, the necessity of regular maintenance, and the potential for gas buildup.
Cost Factors
The high crawl space encapsulation cost is often due to the materials and labor involved. However, the long-term savings in energy costs and the potential avoidance of costly repairs can offset this initial investment.
Regular Maintenance
Once a crawl space is encapsulated, it needs regular maintenance at least once a year. Regular maintenance checks ensure that the encapsulation is still working properly and that the vapor barrier is still in good condition.
Potential for Gas Buildup
Gas buildup can occur if the crawl space is not properly cleaned before encapsulation. Decaying organic matter and sometimes even soils can cause a buildup of carbon dioxide, causing explosion risk or health problems. To prevent this, make sure to properly clean!
When Should You Not Encapsulate a Crawl Space?
Encapsulation may not be suitable for every home. For instance, if your crawl space has severe structural issues or persistent flooding, these problems should be addressed before considering encapsulation.
A sump pump and drainage system will be needed to combat flooding, but structural issues will require professional correction.
Alternatives to Crawl Space Encapsulation
If encapsulation isn’t right for your home, other options include installing a basic vapor barrier or dehumidifier. While these solutions may not offer the same level of protection, they can still provide some moisture control.
Crawl Space Encapsulation Cost
Encapsulation can cost up to $30,000 with an average cost of $15,000, though these numbers can vary depending on the quality of the products used and the state of your crawl space— the worse the damage is, the more the project may cost.
Things That Affect Crawl Space Encapsulation Costs:
- Crawl Space Size
- Materials Used
- State of Crawl Space
- Additional Services Needed*
*Additional services may include mold removal, drainage installation, pest control, or structural repair.
Is It Worth It to Encapsulate a Crawl Space?
For most homeowners, the benefits of crawl space encapsulation outweigh the costs. The improvement in air quality, energy efficiency, and the prevention of mold and structural damage make it a worthwhile investment. The value of crawl space encapsulation can vary depending on various factors, including:
- How long you plan to live in your home
- Whether water regularly intrudes into the crawl space
- Whether you live in a rainy city
Does Homeowner’s Insurance Cover Crawl Space Encapsulation?
Coverage for crawl space encapsulation varies by insurance policy. Typically, standard homeowner’s insurance does not cover this type of work unless it’s part of repairs due to a covered peril. It’s best to check with your insurance provider to understand your specific coverage.
What Do You Need to Encapsulate a Crawl Space?
To properly encapsulate a crawl space, you’ll need:
- A vapor barrier of at least 12-mil – the thicker the vapor barrier, the better it will seal and the longer it will last. 12-mil is the industry standard, but a 20-mil vapor barrier will ensure the longevity of the encapsulation against wear and tear from maintenance.
- Crawl space seam tape – duct tape isn’t a suitable substitute since it is not as wide or as thick as seam tape, allowing moisture to slip through.
- Insulation – professionals opt for rigid foam boards with an R-value of at least 10. R-value measures the ability of the insulation to withstand heat, which is important in hot climates. Some choose to use fiberglass or spray foam insulation, but other than cutting costs, they have several downsides.
- Caulk or foam sealant – used to adhere foam board to walls and to seal vents, caps, and cracks, ensuring an airtight environment.
- Dehumidifier – maintains optimal humidity levels to prevent mold growth and wood rot.
- Drainage System – sump pumps and interior drainage might be necessary if your home is at risk of flooding from heavy rain.
- Safety gear – Personal protective equipment (PPE) should be worn when working in a crawl space. Working with a professional is the best way to ensure your safety.
Safety First!
Before the use of foam board insulation, many installers used fiberglass insulation which can cause irritation to the eyes, nose, throat, and skin. We do not recommend entering your crawl space without proper precautions in place. If you suspect something is wrong, call us for a 100% free inspection!
How to Encapsulate a Crawl Space
- Inspect the crawl space and carry out preparatory work.
- Seal vents, doors, openings, and gaps in the crawl space using spray foam.
- Take flood prevention and water damage control measures.
- Encapsulate the crawl space.
- Install a dehumidifier.
Step 1: Inspection and Preparation
The crawl space needs to be cleaned of old material, dirt, and insulation. You’ll need measurements to install the new insulation, vapor barrier, and drainage properly. If mold is in your crawl space, another specialist may be needed to remove it. Ensure no toxic gasses from combustion appliances seep through to your living space.
TIP: Crawl space encapsulation is just one part of ensuring your home’s protection from water. Yard grading ensures a gentle slope away from the crawl space so that water doesn’t pool against your foundation walls.
Step 2: Seal with Foam
Traditionally, crawl spaces are vented, meaning they’re not air-tight. Sealing openings and vents will curtail the cycle of air and moisture entering the crawl space and leaking into your home. The outcome is warm winters and cool summers. Since the humidity will go down, you shouldn’t need your HVAC running for hours like you used to before.
Step 3: Install Flood Prevention Measures
During heavy rains, homes get overwhelmed with water from the outside. Flooding can cause water damage and moisture problems, including mold growth. If you live in a flood-prone area, installing a perimeter drainage system and a sump pump is a great way of ensuring groundwater doesn’t fill up the crawl space and enter your home.
Step 4: Encapsulate the Crawl Space
The real work starts here. Adhere the foam board insulation to the walls. Then cover the walls and floor with a thick and durable plastic vapor barrier. The barrier will go to the top of the block walls and leave space for a termite inspection. A barrier this thick can withstand regular use by servicemen who frequent the crawl space without tearing. While you can install a barrier of any color, white is the best as it accentuates lighting.
TIP: Different states have specific codes about how vapor barriers are installed. For example, some require that the edges of vapor barriers be overlapped. Ensure your crawl space is within code and that you have enough material to complete the project before beginning.
Step 5: Install a Dehumidifier
Just because you have sealed off the crawl space using a vapor barrier doesn’t mean it will always be dry or free of moisture. To maintain the correct humidity level, you will need to install an energy-efficient dehumidifier. A good dehumidifier should be self-draining (channel excess moisture outdoors) so you won’t have to get inside and drain water into a bucket.
Trust a Crawl Space Encapsulation Contractor Near You
Crawl space encapsulation offers numerous benefits, from improved air quality and energy efficiency to preventing mold and structural damage.
Groundworks has been evolving the home repair industry as the fastest-growing foundation repair and water management solutions provider. We have serviced more than 1,500,000 homes in the U.S. and Canada, granting us the experience necessary to provide the best solution for your home.
Trust our experts for crawl space encapsulation today.
Crawl Space Encapsulation FAQs
When properly installed and maintained, crawl space encapsulation can last 15 to 20 years or more. The vapor barrier, a key component of encapsulation, typically has a lifespan of 20 to 25 years. However, longevity can vary based on factors such as installation quality, climate conditions, and regular maintenance. With proper care, some encapsulation systems can even last the lifetime of the home.
While some homeowners may choose to install insulation themselves, it’s often best to hire a professional to ensure proper installation and address any underlying issues.
Regular inspections, at least once a year, are recommended to ensure that the sealing and encapsulation remain intact and that the dehumidifier is functioning properly.
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Ted Dryce
The information provided in this article is for general informational purposes only and is subject to change without notice. We make no representations or warranties regarding the accuracy, completeness, or reliability of this information. We are not liable for any discrepancies in costs or specifications, nor for any indirect or consequential loss or damages arising from the use of this information. Always consult a professional for an accurate assessment and quote before proceeding with any home repair projects.