How much does it cost to repair a crawl space?

Reviewed by Adam Graham remodeling expert. Written by Fixr.com.

Many homes, especially older homes, have crawl spaces underneath them. These offer various advantages, separating the main structure of the house from the damp earth below and providing easier access to cables, plumbing, and ductwork. However, they can also be a source of various problems, from mold growth and mice infestations to rot damage and other structural weaknesses that need to be fixed.

The national cost average to repair a crawl space is between $500 and $7,500, with most homeowners paying $4,500 to waterproof a 1,500 sq.ft. crawl space. However, costs can be much higher or lower, depending on the repair required. This project’s low cost is $50 to repair a single damaged vent. The high cost is $15,000 to encapsulate a 2,500 sq.ft. crawl space.

Cost to Repair a Crawl Space

Crawl Space Repair Cost by Type of Repair

Various problems can arise with your crawl space, from issues with the insulation to structural weaknesses or deficiencies that need to be reinforced. The issue you have will have a big impact on the cost of your repairs because some issues are much cheaper to fix than others. The table below shows common repairs and the average prices for each, based on a 1,500 sq.ft. crawl space.

Crawl Space Vent Repair

To repair a vent in your crawl space, expect to pay between $50 and $200 per vent. Different problems can arise with different vent types. If you have basic vents, the only things to worry about are damages like holes and cracks. With automatic or powered vents, there can be wiring issues or problems with the sensors that may need readjusting or replacing.

Crawl Space Insulation Repair

Homeowners pay between $750 and $3,500 for insulation repairs. Insulation is a very important part, helping control air temperatures beneath the home and assisting with energy efficiency. Over time, batting and foam insulation can get damaged, wet, and contaminated, so it may need cleaning, repairing, or replacing.

Crawl Space Structural Repair

The average cost of structural repairs to a crawl space ranges from $1,000 to $7,500. Structural repairs tend to be the most expensive to fix and may include damage to the support beams, joists, and other sections of the frame. Mold and rot can set in around the structure, or pests may damage the structure over time. You may require various services to fix this, from mold removal to beam replacement.

Crawl Space Foundation Repair Cost by Type of Replacement

In some situations, parts or sections of the area may be damaged beyond repair and need to be replaced. The cost of replacement parts varies greatly, with some parts being inexpensive and easy to install, but others can cost much more. The table below shows common replacements and average prices for each one for a 1,500 sq.ft. crawl space.

Replacing Vents

To replace vents in your crawl space, expect to pay between $100 and $250 per vent. These vents help keep air flowing through the area and reduce the risk of wood rot, mold, mildew, and pest problems. They can also assist with insulating your home and helping it become more energy efficient.

Replace a Floor Joist in a Crawl Space

Homeowners pay between $100 and $300 to replace a floor joist in this area. If you need several joists replaced, this can become an expensive job, but costs are relatively low for single joists. A joist is a horizontal part of the frame that helps provide stiffness and strength to the structure. Joists may get damaged due to rot or other causes.

Replace Ductwork

The average cost to replace ductwork in a crawl space ranges from $600 to $1,000. The total cost depends on how much ductwork you need. Larger homes require more linear feet of ductwork, resulting in higher costs. Ductwork helps with ventilation under the home but can get damaged due to storms, dirt, debris, and general wear-and-tear.

Replace Insulation in a Crawl Space

It costs between $1,000 and $3,500 to replace insulation in a crawl space. There are two main types of insulation: boards and foam. Boards tend to be cheaper, and the total cost of this project will depend on the amount of insulation required. Insulation helps make your home more energy efficient and can protect the area against moisture damage.

Replace a Vapor Barrier

The average cost to replace a vapor barrier in a crawl space ranges from $1,500 to $4,000. Vapor barriers are an essential element when you want to reduce humidity and moisture inside it, helping lower humidity and reduce the risk of problems like mold, rot, and water build-up. This can be vital for homes in high-humidity areas.

Replacing a Support Beam in a Crawl Space

For support beam replacement in a crawl space, homeowners pay between $1,500 and $5,000 per beam. The support beams are some of the most important parts of the structure, and they can be made of either wood or steel, with steel beams usually costing more to replace. These beams can get damaged due to settling foundations or water damage and will need to be replaced to prevent further structural issues.

Average Cost of Crawl Space Repair by Problem

The cost of your repairs mostly depends on the problem. Some problems are relatively minor, like superficial cracks, but others are more serious, such as mold patches, rotted sections, and mice infestations. The table below shows common problems and the average cost to resolve each for a 1,500 sq.ft. crawl space.

Crawl Space Crack Repair

The average cost to fix cracks in a crawl space is $250 to $1,000. Cracks can appear in various parts of the structure, including joists, beams, and other parts of the framework. As long as they are not too deep, cracks can usually be filled with filler material or resin. If the cracks are deep and threaten the structure of the area, new parts will be needed, such as new sections of wood, beams, or joists.

Mice in a Crawl Space

If mice are running around your crawl space, expect to pay $400 to $600 for professional pest removal services. This price usually includes the initial consultation, plus the cost of traps, sealant, and a follow-up visit to check that the mice have gone. The cost also depends on the level of infestation, with higher prices for more severe cases. It is important to get rid of mice because they can bring diseases into the home.

Mold in a Crawl Space Removal

Homeowners spend between $500 and $2,000 on professional mold removal services for these areas. The total cost depends on the size and the extent of the mold growth. Mold can be quite prevalent in this area due to the high levels of humidity and moisture in these areas, making ventilation very important. Professional mold removal specialists will need to analyze the area and then use special equipment to remove the mold.

Musty Smell

If you notice a musty smell in your crawl space, expect to pay $500 to $2,000 for repairs. A musty smell can be a sign of mold, or it could just be caused by trash left by the previous owners. It may need cleaning or require professional mold removal services.

Wood Rot Repair

Homeowners spend between $750 and $5,000 to deal with wood rot in crawl spaces. Rot can set into various wooden sections over time as the area is exposed to moisture and water. If left unattended, rot can spread and do a lot of damage, so it is important to spot it early on. To fix rot, the rotted sections usually need to be carved out and replaced. Damaged parts of the structure may also need reinforcement.

Fix a Sagging Floor 

Fixing a sagging floor in the crawl space averages $1,000 to $5,000, depending on the size and scale of the problem. A sagging crawl space floor can be caused by structural damage, such as weaknesses in the joists or support beams. The usual way to fix this is to either replace the damaged sections or repair and reinforce them with additional pieces of wood or metal.

Water in a Crawl Space Repair

If there is water in your crawl space, expect to pay between $2,000 and $10,000 to have it removed and repair any damages. If you identify the problem and fix it early, the costs may be low, but the longer you wait, the more damage the water can do. You may need new insulation, replacement beams and joists, water remediation, and possible cleaning and mold removal services.

Crawl Space Repair Cost by Solution

Depending on the issue with your home’s crawl space, repairmen and contractors may need to use a variety of repair methods or solutions. It may require waterproofing to protect against rot and water damage, or it might need cleaning, sealing, or reinforcing due to structural issues and damages. The table below shows the costs of different repair methods for an average crawl space of 1,500 sq.ft.

Clean a Crawl Space

To have your crawl space professionally cleaned, expect to pay between $500 and $2,500. The total dirt removal cost depends on the area size and the level of cleaning required, and costs can be higher if mold or pests are present. Cleaning is necessary if it has been poorly maintained or is old and dirty, with lots of dirt and debris that could cause damage to the structure or attract pests if left unattended.

Seal a Crawl Space

The average cost to seal a crawl space ranges from $500 to $4,000. The total price depends on the level of sealing you require. Simply sealing the vents can be done inexpensively, but the price will be significantly higher if you want the entire area and all entry points sealed. Sealing is a good method to protect against pests, rodents, and excess moisture.

Reinforce a Crawl Space

Homeowners pay between $1,000 and $5,000 to reinforce a crawl space. Reinforcement may be needed if it has suffered structural damage, rot damage, or other problems that have affected its structural integrity. Extra materials and wood beams may need to be added to the frame and structure to strengthen it and reduce the risk of future damages.

Crawl Space Restoration

To restore your crawl space, expect to pay $1,500 to $7,500. Restoration is usually recommended when it is old, badly damaged, or in a state of disrepair. The process can involve dealing with superficial damages like cracks and holes, removing and replacing any rotted or broken sections, and restoring the structure to its original state.

Crawl Space Waterproofing

Homeowners pay between $2,000 and $7,000 on waterproofing. Waterproofing can involve a variety of measures, such as installing vapor barriers and sealants to make it fully waterproof. This can be a costly procedure, but it greatly helps reduce the risk of issues like mold, rot, and moisture damage.

Crawl Space Encapsulation

The average cost for crawl space encapsulation is between $2,000 and $15,000, or between $2 and $6 per sq.ft. Encapsulation is a great way to regulate humidity and prevent issues like mold, mildew, and radon gas. The process can involve cleaning, installing a vapor barrier, sealing, fitting a sump pump, adding a dehumidifier, and carrying out structural repairs. More extensive levels of encapsulation will have higher costs.

Crawl Space Water Remediation

Homeowners spend between $2,500 and $10,000 on water remediation. Costs can be on the higher end of this range if it has been seriously waterlogged and damaged, and you may have to add on a fungus treatment cost of between $1,000 and $3,000 if fungi have begun to grow.

Labor Cost to Repair a Crawl Space

Labor costs for repairing crawl spaces vary from $50 to $150 per hour. You may have to hire various professionals to deal with these issues, from exterminators for dealing with mice infestations to mold removal specialists, carpenters, plumbers, and other contractors, so prices vary depending on the type of worker and level of experience required. You may also have to pay extra for emergency work and fees if you live in a remote location and workers have to travel long distances to get to your home.

Maintenance

One of the best ways to minimize the risk of crawl space problems and costly repairs is to keep it in good condition. There are several steps that homeowners can take to protect these areas, beginning with keeping them clean and clear. Some homeowners get into the habit of leaving old materials and debris in this area, but this can make pest infestations more likely and the area more difficult to access. It is best to keep it clear, inspect it often, and keep it as clean as you can.

Other steps you can take to protect and maintain this area include installing a vapor barrier to protect against moisture damage and sealing any holes or cracks that insects or mice could use to get into the crawl space and do damage beneath your home. It is also recommended to insulate it to help with temperature control. Also, consider sump pump installation if there is a lot of moisture and humidity.

Crawl Space Inspection Cost

Crawl space inspections typically cost between $100 and $300. Having regularly inspections, such as once per year, can help minimize repair costs by identifying issues early and getting them fixed before they become more serious. During an inspection, a professional crawl space specialist will look for signs of issues in the area, such as standing water, signs of rodents or insects, insulation damage, moisture around the ductwork, wood rot, and dirt. They will give you a full report of their findings and tell you if any extra steps need to be taken.

Enhancement and Improvement Costs

Dehumidifier

Homeowners spend between $750 and $1,700 on crawl space dehumidifiers. A dehumidifier helps reduce the humidity levels, reducing the risk of mold development. Having a dehumidifier installed can be key for preventing mold and protecting your home.

Vapor Barrier

Getting a vapor barrier installed in your crawl space averages $1,500 to $4,000 in total, and the price mainly depends on the size and the amount of material needed to form the vapor barrier. Vapor barriers reduce humidity levels and block moisture from building up inside the crawl space, so they can help reduce the risks of mold, rot, and water damage to the structure.

Additional Considerations and Costs

• Ask for different quotes. Crawl space repairs can be costly, so to save money, it is a good idea to speak with different repair companies and compare quotes before deciding who to hire.
• License. Always work with licensed professionals for best results when having any kind of home repairs, including repairs.
• Permit. You may need a permit when undertaking certain repairs or improvements, such as vapor barrier installation or mold remediation, so check with your local building authority for more information before starting the work.
• Insurance. Your homeowners insurance policy may cover certain damages and issues with your home’s crawl space, so check the details of the policy and see if you can make a claim.
• Lifespan. Properly insulated and well-maintained crawl spaces can last for 50+ years, but as they get older, they will be more likely to require regular repairs and new parts.
• Size. The size can impact repair costs in certain cases, especially when work needs to be done to the entire crawl space, such as cleaning the area or installing a vapor barrier.