How Much Does Floor Joist Replacement Cost in 2025?
The average cost to replace floor joists is $6,000
Replacing floor joists costs an average of $6,000, with most homeowners paying between $4,000 and $12,000.
Key cost factors include accessibility, flooring type, labor, and the extent of damage.
If you need to replace all the joists in one space, budget $10 to $67 per square foot.
Flooring repair specialists charge between $65 and $100 per hour and are essential for maintaining structural integrity and ensuring code compliance.
This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.
Most homeowners spend between $4,000 and $12,000 to replace floor joists. Minor fixes can run as low as $1,000, while replacing every joist in a 300-square-foot room can push costs up to $20,000. You can expect to pay an average of $6,000, or between $100 and $300 per joist, depending on the extent of damage and accessibility of the joists to your contractor. Proper budgeting and hiring a professional are essential to ensure a safe and long-lasting repair.
Floor Joist Replacement Cost Factors
Several factors influence the total cost of a floor joist replacement, including the room size, accessibility, the number of joists that require replacement, and local labor rates.
Size
If you’re replacing all floor joints in a space, the room's size will significantly impact your total costs. Expect to pay between $10 and $67 per square foot, depending on the amount of labor required.
| Room Size (Sq. Ft.) | Average Cost Range |
|---|---|
| 100 | $1,000–$6,700 |
| 150 | $1,500–$10,050 |
| 300 | $3,000–$20,100 |
| 350 | $3,500–$23,450 |
| 500 | $5,000–$33,500 |
Accessibility
Flooring contractors often replace joists from below, either through a crawl space or an unfinished basement ceiling. For rotting joists in a second-story room, they may need to remove and replace the flooring and subflooring to access the damage, which significantly increases the project's cost. Remove furniture and appliances ahead of time to trim labor costs.
Flooring and Subflooring
Installing new flooring costs between $2 and $22 per square foot, with an average price of $12.50 per square foot. Subfloor repair costs $2 to $10 per square foot, or $500 to $700 per room, while complete subfloor replacement costs between $1,800 and $3,000 per room.
If you need to remove and replace flooring during joist replacement, the type of flooring will impact your total cost. Repairing hardwood floors or tile is more expensive than installing laminate flooring due to the more complex installation process and higher labor and material costs.
Labor
Hiring a floor repair professional near you costs between $65 and $100 per hour. Most joint repair projects require between five and 24 hours of work, depending on the scope and complexity. Labor rates rise with project difficulty, the pro’s experience, and local market rates. Consider prepping the space in advance—remove rugs, furniture, and appliances—to shorten the time your contractor spends on site and lower the final bill.
Extent of Damage
Replacing all joists on one level can cost $20,000. Severe damage can increase costs to up to $30,000, depending on the square footage of your home. The more extensive the damage, the higher your costs will be.
Termites and prolonged water exposure can damage joists, so you'll need to address these issues before replacing the joists. Extermination or moisture remediation costs vary greatly. If you've noticed sagging floors, insect damage, or moisture issues, consider contacting a general contractor for professional floor joist repair to receive an accurate estimate.
Floor Joist Replacement Cost by Type
There are several types of floor joists to choose from, including engineered I-beams, 2x10 joists, and open-web floor truss joists. Each of these types varies in its cost, durability, and installation method.
| Type of Joist | Average Price |
|---|---|
| Engineered I-beam joist | $40 per 16 feet |
| 2x10 joist | $30 per 16 feet |
| Open-web floor truss joist | $30–$70 |
Floor Joist Installation Cost
Replacing floor joists is a major structural repair to your floor, often requiring the use of professional tools and the expertise of a trained contractor. The total project cost for complete joist replacement is between $5,000 and $20,000 for a 300-square-foot room, although you may spend more than $20,000 if all the flooring needs to be replaced.
Unless your joists are easily accessible from a crawl space or an unfinished basement ceiling, joist replacement will likely also involve subfloor replacement costs and the replacement of floor coverings.
Replacement Cost Per Joist
Minor joist repairs cost between $100 and $300 per joist, while full replacements range from $1,000 to $2,000 each, especially if the joists are insulated or hidden beneath flooring and subflooring. For full replacements, flooring contractors often provide pricing for the entire project based on the total number of joists involved.
Cost by Extent of Damage
Joist replacement is often necessary when a joist has rotted due to damage from insects or excessive moisture. The scale of your floor repair project depends partly on the extent of this damage.
Sistering
On average, sistering will cost you $100 to $300 or more per joist. Sistering involves clearing rot, treating the wood, and laying a new joist beside the old one. However, these costs will increase if your contractor needs to open up a floor or ceiling to access the joists.
Partial Room Replacement
A minimal replacement costs $1,000 per joist. If only part of your room suffered damage, you might only need to replace a few joists rather than all of them. The more joists that need to be replaced, the higher the cost you can expect to pay.
Full Room Replacement
Full room replacements cost between $5,000 and $20,000, with the possibility of exceeding $20,000 for severe damage. If your space has experienced extensive damage, you may need to replace all the joists in the room.
Entire Level Replacement
In some cases, damage is so widespread that an entire level of a home is compromised. In this instance, you'll need to replace all the joists on that level, which will cost up to $30,000. The larger your level, the more you'll likely have to pay.
Floor Joist Replacement vs. Repair
Deciding between repairing and replacing floor joists depends on the extent of the damage. For cracked joists, sistering is an effective and affordable repair method that avoids raising large floor sections. However, if joists are rotten, moisture-damaged, or significantly compromised, replacement is usually the better option. If many joists are affected, replacing them all at once may be a more cost-effective approach. Consult a flooring professional to determine the best choice for your home.
Budgeting for Floor Joist Replacement
The cost of floor joist replacement depends on the size and extent of the damage, as well as the accessibility of the space. To keep your project within budget, consider the following tips:
Clear out rugs, furniture, and appliances before your pro arrives to cut labor time.
Take advantage of crawl spaces or unfinished basements so the crew doesn’t have to tear up flooring.
Choose sistering over complete replacement whenever the joist is still structurally sound.
Address moisture or insect issues promptly to prevent further damage.
Gather at least three quotes from seasoned contractors to strike a balance between price and quality.
If your repairs require removing a section of flooring, you can also explore flooring repair costs for tips on the best flooring solutions for your budget.
How HomeAdvisor Gets Its Cost Data
No place is more important than your home, which is why HomeAdvisor connects homeowners with local pros to transform their houses into homes they love. To help homeowners prepare for their next project, HomeAdvisor provides readers with accurate cost data and follows strict editorial guidelines. After a project is complete, we survey real customers about the costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Frequently Asked Questions
You should replace floor joists as soon as you see clear signs of structural trouble—sagging floors, wide wall cracks, uneven door frames, wet or rotting wood, persistent squeaks, or windows that no longer latch. Tilted or sinking supports in the crawl space are another red flag. If you notice any of these signs, call a pro right away to keep your home’s structure safe.
If the joists are exposed from below, a pro can swap them out without touching the finished floor above. In an unfinished basement or crawl space, you’ll often see the joists and can easily reach them. When insulation, subflooring, or finished flooring blocks access, the crew must remove these materials before repairs can begin.
Sistering allows a pro to reinforce a cracked or undersized joist without tearing up the entire floor. The contractor slowly raises the frame, then fastens a new joist snugly against the damaged one to share the load. When done correctly, sistering restores full structural strength and keeps the floor level without the cost of a complete replacement.
Floor joists installed correctly in a stable environment can last for 100 years or more, often outlasting the house itself. However, termite damage, moisture, leaks, and other problems can significantly reduce a floor's lifespan. For instance, if the floor is exposed to consistent moisture, you'll likely need to replace the joists every 20 to 30 years.
Homeowners' insurance covers floor joist damage resulting from sudden and accidental events, such as fire, windstorm, or water damage from a burst pipe. It will not cover repairs resulting from gradual deterioration, poor maintenance, or termite infestations. Review your insurance policy and consult your provider to verify the conditions that guarantee full coverage. Doing so ensures you are fully aware of your responsibilities and can plan your repair work with complete confidence.
Floor joists are essential structural components that provide a stable foundation for your home. They directly transfer the weight of floors, furniture, and occupants to the foundation, ensuring stability and a safe living environment. Without these robust beams, the structure would face compromised load distribution, leading to potential safety hazards and costly repairs. Proper installation and maintenance are crucial for long-term durability and safety.
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