Subfloor Replacement Cost Calculator

How Much Does Subfloor Replacement Cost?

$500 to $3,000 per room is the typical cost to replace a subfloor, with most homeowners paying around $1,500 per room or $3 to $10 per square foot installed. A small bathroom subfloor replacement might run $400 to $800, while a large living room or kitchen can reach $2,500 to $4,000. The final price depends on the area size, the subfloor material you choose, the type and extent of damage, and whether the floor joists underneath also need repair.

Subfloor replacement is one of those projects that most people never think about until something goes wrong. A soft spot near the toilet, a section of hardwood that keeps buckling, or a musty smell from beneath the floor are all signs that the subfloor panels have deteriorated. Catching it early and replacing just the damaged sections keeps costs on the lower end. Waiting until damage spreads to the joists or adjacent rooms can double or triple the bill. If mold is present under the subfloor, you may need mold remediation ($1,500 to $4,000) before the new subfloor goes in.

Subfloor Replacement Cost by Material

$1.50 to $8 per square foot is the range across common subfloor materials. Here is how each option compares.

Material	Cost per Sq Ft (Installed)	Best For
OSB (oriented strand board)	$1.50 - $4.00	Budget-friendly, standard residential use
Plywood (3/4" CDX)	$2.00 - $5.00	Most popular choice, strong screw hold
AdvanTech / premium panels	$3.00 - $6.00	Moisture-prone areas, premium builds
Cement board (1/2" or 3/4")	$4.00 - $8.00	Bathrooms, kitchens, tile floors

Cost Breakdown by Project Size

$300 to $8,000+ depending on square footage. Here is what typical projects cost using standard plywood.

Project Size	Low End	Average	High End
Small patch (25 - 50 sq ft)	$200	$400	$600
Bathroom (50 - 100 sq ft)	$400	$750	$1,200
Bedroom (100 - 200 sq ft)	$600	$1,200	$2,000
Kitchen / living room (200 - 400 sq ft)	$1,200	$2,200	$3,500
Multiple rooms (500+ sq ft)	$2,500	$4,500	$8,000

Factors That Affect Subfloor Replacement Cost

$3 to $10 per square foot is the installed range, and these factors determine where your project falls.

Material Type

Plywood at $2 to $5 per square foot installed is the go-to choice for most subfloor replacements. Standard 3/4-inch CDX plywood offers excellent strength, holds screws securely, and works under any finished flooring. OSB at $1.50 to $4 per square foot is the cheapest option and works well in dry areas, but it absorbs moisture faster than plywood and can swell if exposed to water. Cement board at $4 to $8 per square foot is the best option for bathrooms and other wet areas because it will not rot, warp, or support mold growth. AdvanTech at $3 to $6 per square foot is a premium engineered panel that resists moisture better than standard plywood and stays flat during construction, making it popular for high-end builds and remodels.

Damage Cause and Extent

Water damage is the most common reason for subfloor replacement and typically costs more than age-related wear because the damage often extends beyond the visible area. Contractors usually find that water-damaged subflooring has spread to adjacent panels that look fine from above but are soft underneath. Termite damage adds complexity because a pest inspection and treatment ($200 to $500) should happen before new subfloor goes down. Structural damage from settling or overloaded floors may require sistering or replacing joists, which adds $100 to $300 per joist to the project.

Flooring Removal

$1 to $4 per square foot is the added cost if the finished floor above needs to be removed first. Carpet is the cheapest to pull up ($0.50 to $1.50 per square foot). Hardwood and engineered wood run $1.50 to $3 per square foot to remove. Tile is the most labor-intensive at $2 to $4 per square foot because of the thinset mortar that has to be chipped off. If you plan to install new flooring afterward, hardwood floor refinishing ($1,000 to $3,000 per room) or tile flooring ($1,000 to $5,000 per room) are popular choices that pair well with a fresh subfloor.

Joist Repair

$100 to $300 per joist is the typical cost if floor joists underneath the subfloor are also damaged. Water that rots a subfloor panel often damages the joist below it as well. Sistering (bolting a new joist alongside the damaged one) is the most common repair method and runs $100 to $200 per joist. Full joist replacement costs $200 to $300 per joist. Most single-room subfloor replacements need zero to two joist repairs. Severe water or termite damage may require three or more, adding $500 to $1,500 to the project total.

Access and Location

Second-story and hard-to-reach subfloors cost 15% to 30% more than first-floor work because materials have to be carried upstairs and debris hauled down. Bathrooms in the center of a home with no crawl space access below are also more expensive because the only option is to work from above, requiring full flooring removal. First-floor rooms over a crawl space or unfinished basement are the easiest and cheapest to work on.

OSB vs Plywood vs Cement Board for Subflooring

$1.50 to $8 per square foot is the range, and each material has clear strengths and trade-offs.

Feature	OSB	Plywood	Cement Board	AdvanTech
Cost (installed)	$1.50 - $4	$2 - $5	$4 - $8	$3 - $6
Moisture resistance	Low	Moderate	Excellent	Very good
Strength	Good	Very good	Good	Very good
Best use	Dry rooms	General use	Bathrooms, wet areas	Premium builds
Lifespan	20 - 30 years	25 - 40 years	30 - 50 years	30 - 50 years

For most rooms, 3/4-inch CDX plywood is the best balance of cost, performance, and durability. OSB saves money in dry bedrooms and living rooms where moisture is not a concern. Cement board is the clear winner for bathrooms and laundry rooms, especially under tile. AdvanTech is worth the premium if you want top-tier moisture protection without switching to cement board.

How to Save Money on Subfloor Replacement

$200 to $1,000 in potential savings is realistic with these strategies.

• Replace only damaged sections. A full-room subfloor replacement costs significantly more than cutting out and replacing just the rotted panels. If damage is limited to a 4x4 or 4x8 section near a toilet or tub, a patch repair can save 40% to 60% compared to replacing the entire room.
• Remove the flooring yourself. Pulling up carpet, laminate, or vinyl yourself before the contractor arrives saves $1 to $3 per square foot in demo labor. Tile removal is harder to DIY but still possible with a rented floor scraper.
• Choose OSB for dry areas. If the subfloor is in a bedroom, hallway, or living room with no moisture exposure, OSB at $1.50 to $4 per square foot gets the job done at 25% to 30% less than plywood.
• Bundle with flooring installation. If you are already replacing the subfloor, getting new flooring installed at the same time is cheaper than two separate projects because the contractor is already on site with the room cleared.
• Fix the water source first. Replacing a subfloor without fixing the leak, condensation, or drainage problem that caused the damage is throwing money away. The new subfloor will rot the same way. Spend $150 to $500 to fix the source before spending $1,500 on new panels.

Frequently Asked Questions

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