How Much Does Replacing Floor Joists Cost in 2025?

This article was updated using automation technology and thoroughly reviewed for accuracy by HomeAdvisor Editor Ryan Noonan.

Replacing floor joists costs most homeowners between $4,000 and $12,000, with severe damage costing up to $20,000. You can expect to pay an average of $6,000, or anywhere from $100 to $300 per joist, depending on the damage extent and how accessible the joists are to your contractor.

Floor Joist Replacement Cost Factors

Several factors can influence the total cost of a floor joist replacement. For instance, if your floor is tough for a pro to reach, it will require more time and labor to fix, which drives up costs.

Accessibility

Your contractor typically replaces 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 flooring and subflooring to access the damage, significantly increasing the project's cost. You can reduce labor costs by removing furniture and appliances yourself.

Flooring and Subflooring

Installing new flooring costs between $2 and $22 per square foot, averaging around $12.50. Subfloor repair costs $2 to $10 per square foot or $500 to $700 per room, while full subfloor replacement ranges from $1,800 to $3,000 per room. You can lower installation costs by choosing a floating floor.

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 laminate flooring due to more complex installation and higher labor and material costs.

Labor

Hiring a floor repair professional near you typically costs between $65 and $100 per hour, and a joist repair project may require 5 to 24 hours of work, depending on the scope and complexity. Labor rates vary based on the job's difficulty, the contractor’s experience, and your location. You can save on labor costs by preparing your space in advance. Remove rugs, furniture, and appliances to reduce the time your contractor needs to spend in your home.

Extent of Damage

Replacing all joists on one level can cost between $10,000 and $20,000. Severe damage can push costs up to $30,000, depending on your home's square footage. The more extensive the damage, the higher your costs. 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 problems, consider contacting a general contractor for professional floor joist repair.

Floor Joist Prices by Type

Engineered I-Beam Floor Joists

The average cost for a standard 16-foot engineered I-beam joist is $40. This type of joist is made from plywood, oriented strand board (OSB), particleboard, or fiberboard placed between standard lumber in the shape of an 'I.' Engineered I-beams can span greater distances than other joists with minimal sagging over time.

2x10 Joists

A popular choice for floor joists, 2x10s cost about $30 per 16-foot joist. Made from softwood lumber, they can be cut to custom lengths more easily than engineered I-beams. However, they may warp or bow over time due to natural wood construction and often require purchasing more joists since they don't span as far.

Open-Web Floor Truss Joists

Open-web floor truss joists feature two 2x4s with an inner wood or metal web, costing $30–$70 each. They minimize shrinking, squeaking, and bowing and allow for easy installation of electrical wires and some pipes.

Floor Joist Total Installation Cost

Replacing floor joists is a major structural repair to your floor, often requiring the professional tools and knowledge of a trained contractor. The total project cost for full joist replacement is typically $5,000 to $20,000 for a 300-square-foot room. Additionally, 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 floor covering replacement.

Floor Joist Installation Cost Per Joist

Minor repairs cost between $100 and $300 per joist if your contractor can easily access them from below. More extensive repairs may cost up to $1,000 per joist. Full replacements range from $1,000 to $2,000 per joist, especially if joists are insulated or covered by flooring and subflooring. Contractors typically price full joist replacements as a total project based on the number of joists.

Floor Joist Replacement Cost by Extent of Damage

Joist replacement is usually necessary when a joist has rotted away due to damage from insects or 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 joist replacement typically costs $2,000 to $5,000. If only part of your room suffered damage, you might only need to replace a few joists rather than all of them. Generally, the more joists you need replaced, the more you can expect to pay.

Full Room Replacement

Full room replacements typically cost between $5,000 and $20,000, with the possibility of exceeding $20,000 for severe damage. If your room experienced extensive damage throughout, you may need to replace all of 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 of the joists on that level, typically costing $10,000 to $30,000. The larger your level, the more you'll likely have to pay.

Floor Joist Replacement vs. Repair

Deciding between repairing or replacing floor joists depends on the damage extent. 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 better. If many joists are affected, replacing them all at once may be more cost-effective. Consult a professional to determine the best option for your floor joists.

Budgeting for Floor Joist Replacement

The cost of floor joist replacement depends on the size and extent of the damage and how accessible the space is. A home inspector can help you estimate the work needed so you can budget accordingly.

Here are some cost-saving tips for floor joist replacement:

• Remove rugs, furniture, and appliances beforehand to reduce labor costs.

• Use accessible areas like crawl spaces or unfinished basements to avoid removing flooring.

• Opt for sistering joists instead of full replacement when possible.

• Address moisture or insect issues early to prevent further damage.

• Obtain multiple quotes from experienced contractors to find the best price without sacrificing 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.