Crawl Space Encapsulation: A Cost Guide

If your home is slightly elevated, you may have a crawl space beneath your ground floors. Unfortunately, these areas are often left overlooked. When things get out of hand, untidy crawl spaces may put you at risk of several health issues. Pests such as rodents and birds may even thrive in the environment.  Additionally, a poorly insulated crawl space may also cause significant heat loss– resulting in mold growth and dust accumulation. In short, it will only bring nothing but bad news if you’re O.C. about your living environment. 

But you probably already knew that; that's why you're here!

 On average, for a single family residential of about 1900 sqft, crawl space encapsulation will cost you about $6,325 on crawl space encapsulation costs.

Here's the break down table for that...

Item

Qty

Low

High

Batt Insulation

Non-discounted retail pricing for: R25 15" x 40' insulation batt roll for friction fit installation between common framing. R 3.4 per inch of thickness.

2029 sf

$2165

$5065

Crawl Space Insulation Labor, Basic
Basic labor to insulate crawl space with favorable site conditions. Fit and secure batt insulation between floor joists. Includes planning, equipment and material acquisition, area preparation and protection, setup and cleanup.

24.7 hrs

$854

$2041

Crawl Space Insulation Job Supplies
Cost of related materials and supplies typically required to insulate crawl space including: fasteners, vent flow baffles and sealing tape.

2029 sf

$246

$280

Project Totals

1900 sf

$3,265

$7,385

Of course there is no one size fits all pricing to crawl space encapsulation.  In this guide we'll break down all the details and intricacies so that you will be a savvy consumer before contacting a contractor!

There are several reasons for you to consider crawl space encapsulation. Need additional space underneath the ground floor? Are you tired of the consistent musty smell or frustrated by the persistent allergens in the air?

It might be high time to consider encapsulating your crawl space. 

What is Crawl Space Encapsulation? 


Before jumping right into the average cost of crawl space encapsulation, let’s first discuss what it is all about. To put it simply, it creates a protective barrier in your crawl space, AKA the area between the floor and the ground, to serve as insulation against humidity.  

Encapsulating your crawl space also prevents any pest activity and reduces your recurring utility costs. The process is renowned for being very intricate, and it has become one of the most popular home improvement projects in recent years.

Opt to encapsulate your home’s crawl space if you are dealing with:  

  • Current pest problems
  • Condensation issues
  • Presence of mold or mildew
  • Consistent musty odor
  • Soft, separating floors
  • Wet insulation
  • Visible cracks in your home’s foundation
  • Excessive HVAC expenses

If your property is situated in hot, humid environments– your crawl space will deal with a much higher risk of getting damaged by moisture. Older homes with vented spaces may also deal with the same heightened risk. Consult a local home foundation professional for a crawl space assessment if any of these conditions apply to your situation.

Aside from addressing existing problems, you can also invest in a complete crawl space encapsulation system to save yourself from future-related issues. 

Factors Affecting Crawl Space Encapsulation Costs 


As mentioned above, some significant variables may only hike up the expenses on crawl space encapsulation. 

Materials


Typically, you will need materials such as a dehumidifier, vapor, thermal barriers, lighting, insulation, and a drainage system. The insulation alone can be pretty expensive, costing you up to $345 depending on the total crawl space size. Some encapsulation systems only consist of a single-layer thin plastic liner, while high-end options include a thick, multi-layer vapor barrier, dehumidifier, or sump pump.

Any additional features will only cost you more. Let’s discuss some of the most common materials you’ll need for this project: 

  • Foundation Wall Insulation - Depending on your crawl space size and ventilation, your contractor can recommend an insulation type that fits your needs.  It will cost you somewhere between $0.50 and $1.50 per board foot.  Of course, batting varies, starting at $3 for a single roll and up to $345 for large areas.  Foundation walls are typically covered in a rigid, R-value foam board before the insulation gets installed in place.  Previously, fiberglass insulation material proved to be the most popular choice for crawl spaces. However, the material will only absorb and store moisture over time.  It only encourages rotting as well as the growth of annoying mold and mildew. It will also invite pests: such as termites, rodents, and mosquitoes.  Perhaps the most efficient choice is spray foam insulation material– which can get into crevasses and small cracks. It costs $11 to $17 per linear foot surrounding the area.

  • Vapor Barrier Prices - Some homes already have a vapor barrier in their crawl space– a plastic layer measuring 3 to 6 millimeters laid beneath the floor.   This insulation material is expected to keep away all the odors and vapors from seeping into your property. However, it doesn’t keep out moisture and will break down after 5 to 10 good years.  A vapor barrier (20-millimeter thick) will cost you $0.50 to $0.70 per square foot. With a 4-inch by 180-foot roll tape to secure it, expect an additional $57.  Meanwhile, the labor charges will depend on the size of the space and the thickness of the material.  Although you will cut costs on thin, affordable plastic, this may risk ripping quickly. Meanwhile, thicker sheets are sturdier and will keep out moisture more effectively. 
  • Seal Vents - After fixing leaks and installing encapsulation, it is time to seal the air leaks and exterior vents.  Vent covers will cost you $17 to $25 per piece. Usually, your contractor uses insulation to seal air leaks surrounding the sill plate, rim joist, and pipes or cables.  An indoor A.C. unit will help keep your living space dry. So if you have an HVAC duct system at home, installing new vents will be more cost-effective.   When an existing HVAC duct system is present, installing vents can be cheaper on your end. 
  • Drainage System - Some properties may have their crawl space below ground level, while others may live in a locality known to have a high water table.  If any of these two apply to your home– you may need to install a sump pump in your encapsulation system. It runs for $1,500.  Pedestal pumps will cost you $70 to $195, while a submersible unit costs $115 to $460.  Ideally, you will need a powerful sump pump to discard groundwater efficiently during times of heavy rainfall.   Units with an airtight lid are preferred since they prevent water pooling and evaporation.  Sump pumps with floor drains and leak alarm systems also make for a great choice, by the way. 
  • Dehumidifier Costs - If you live in an area with high humidity levels, it’s best to consider a dehumidifier (from $920 to $1,380, excluding installation fees) alongside your vapor barrier.  Professional-grade dehumidifier units are large enough to accommodate more vast spaces, and they can also effectively deal with higher moisture levels.  Fluctuating changes in humidity and temperature may only be the reason for substantial condensation in your HVAC units and pipes.   To prevent moisture accumulation in your crawl space, opt to install a dehumidifier at home. Bonus: it also cleans and improves indoor air quality.  

Crawl Space Condition


Is your crawl space in bad condition? Naturally, if your contractor has to first deal with drainage, mold, and pest problems, it will only add up to the project total. Hence, better prepare your budget for higher crawl space encapsulation expenses.

In some cases, you may need to personally clean your crawl space area (or hire professional cleaning services) before the encapsulation process. Any rocks and other debris need to be removed from the area, as they may only rip the vapor barrier. Fortunately, the majority of professional encapsulation project quotes already cover the cleaning aspect.  

Labor


Hiring professional contractors for the job will only hike up the project costs. No “one price fits all” for this. It depends primarily on the local labor rates, the contractor’s level of experience, and the complexity or scope of the crawl space encapsulation project. 

Permits


Depending on your locality, some homeowners may need to secure city or state permits to begin their home improvement project.

In particular, North Carolina requires a permit if the crawl space encapsulation service costs over $15,000. The permit costs will significantly vary depending on where you are located. 

Repair


Besides crawl space cleaning, you may also need to repair the area before encapsulation. Any existing moisture damage must need to be addressed first. Standard repairs start at $1,725 up to $15,000, depending on the repair severity and scope of the fix needed.

You may need to prepare your budget accordingly for more severe and expensive issues, such as mold remediation, settling, or sinking. 

Maintenance


With all the pipes and wiring in your crawl space, you may need to seek the assistance of a plumber or electrician to do routine maintenance activities. Don’t worry. It wouldn’t damage your installed vapor barrier if you installed a thick, high-quality system.

Doing any work near the wall may break a seal for later replacement. Case in point: water supply pipelines.  

Crawl Space Encapsulation Project Process 


Let’s take a closer look at the step-by-step process of a crawl space encapsulation project.

  1. 1
    Area Preparation: Debris like sharp rocks and anything that may puncture the insulating plastic must be removed. Then, the ground is graded to make the most level surface possible. 
  2. 2
    Sealing: Seal any external openings on your walls, such as doors and vents. Wires and pipes from the outside must also be sealed properly.  It will allow you to block any unwanted airflow while helping to waterproof the space. The material to be used might be plastic or foam, depending on your contractor. 
  3. 3
    Insulation: Walls and floors are added with an insulating layer of plastic. Ideally, your flooring should have plastic with at least six millimeters in thickness and should overlap by one foot to cover the whole area. The plastic will be very durable to withstand termite inspections, plumbing, and other disturbances with the right thickness.  
  4. 4
    Conditioning: When the space is sealed off, any existing moisture is removed from vents leading to the living room. In some cases, you may also consider installing a trusty dehumidifier for the job.   Lastly, consider adding a pump and flood alarm if your home is located in flood-prone areas. 

What are the Benefits of Crawl Space Encapsulation? 


So, is crawl space encapsulation worth the cost? Why are more homeowners starting to see the importance of crawl space encapsulation?

There are several benefits to this particular home improvement project. For starters, it solves previous construction mistakes such as vented crawl spaces. Doing so will also help you address environmental concerns, such as high levels of humidity and toxins, especially if you live in an area with warm, wet climates.

Solving the problems at once is crucial so you won’t have to deal with the issues later, especially when the crawl space structure is put at risk. Here are some other benefits you can expect in a crawl space encapsulation project: 

  • Better Indoor Air Quality - Gases from the soil (dust and allergens) are blocked efficiently. Keep in mind that the air in a crawl space will circulate in your household through the ducts, floors, and partitions. 
  • Energy Efficiency - Any cold or warm air will affect your HVAC unit efficiency. Thanks to the additional insulation in your crawl space, you will enjoy reduced utility bills in no time. 
  • Pest Control - It keeps the pests and rodents away. With the airtight barrier, any insects will have difficulty infiltrating the space. 
  • Mold Protection - With reduced moisture, your crawl space has a lesser risk of mold growth. (Related: Mold in Crawl Space: The Causes & Solutions Homeowners Need To Know About)

Homeowners who aren’t experiencing any trouble with their crawl spaces may think they don’t need to encapsulate it at all.

However, it makes for a wise investment if you consider all the benefits involved. Trust us; you will be thanking yourself for all the advantages beyond the initial costs.  

Should I Hire a Crawl Space Encapsulation Professional? 


Hiring an experienced professional can adequately assess your home’s crawl space to give you the encapsulation fit to your needs. While some homeowners have adequate knowledge of improvement projects, it’s ideal to seek the expertise of an insured contractor trained to work with crawl spaces.

Most professional quotes will already cover the labor and material costs for your project. Consider it to be an excellent investment on your end– as you may potentially prevent mistakes or low-quality encapsulation work leading to expensive repairs.

Kenneth Wilson
October 5, 2021
Cost Guides, Interior

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done.