Subfloor Replacement Cost (2026)
Replacing a subfloor costs $4 to $10 per square foot, putting most jobs between $1,200 and $7,000. A bathroom runs $700 to $3,000, a 200-square-foot room $1,200 to $5,000. The number on the quote is usually only the subfloor; taking up and relaying the finished floor above it, and repairing any joists found rotted underneath, are separate lines.
- How much does it cost to replace a subfloor?
- Subfloor replacement costs $4 to $10 per square foot, or $1,200 to $7,000 for most jobs. A bathroom is $700 to $3,000, a 150 to 200 square foot room $1,200 to $5,000, and a whole 1,000 square foot floor $4,000 to $12,000. Removing and relaying the finished flooring adds $2 to $12 per square foot.
- Plywood or OSB for a subfloor?
- Both are acceptable and priced within a few dollars a sheet of each other — 3/4-inch tongue-and-groove sheets run $30 to $70. Plywood tolerates getting wet and drying out better; OSB swells at the edges if soaked. Over a crawl space or in a bathroom, plywood or a moisture-resistant engineered panel is worth the small premium.
- What causes a subfloor to rot?
- Water from above — a leaking toilet seal, shower pan or dishwasher — or moisture from below, which over a crawl space means high humidity condensing on the underside of the floor. Replacing a subfloor rotted from below without dealing with the crawl space humidity means replacing it again.
- Can I replace a subfloor myself?
- A small section, if you are comfortable cutting back to the centre of the joists and screwing and gluing new panels. Material cost is $2 to $4 per square foot. Larger areas, anything involving a toilet flange or plumbing, and anything where the joists are also damaged are better left to a carpenter.
| What you're pricing | Low | Typical | High |
|---|---|---|---|
| Small patch, under 20 sq ftAround a toilet, at a doorway | $250 | $500 | $1,000 |
| Bathroom, 40–60 sq ftIncludes pulling and resetting the toilet | $700 | $1,500 | $3,000 |
| Room, 150–200 sq ftKitchen, bedroom, living area | $1,200 | $3,000 | $5,000 |
| Whole floor, 1,000 sq ft$4–$12 per sq ft | $4,000 | $7,500 | $12,000 |
| Mobile home subfloor, per roomParticleboard replaced with plywood | $400 | $1,000 | $2,500 |
| Add: remove and relay finished flooring$2–$12 per sq ft depending on the floor | $400 | $1,500 | $4,000 |
| Add: sister rotted joists found beneath$100–$400 per joist | $300 | $1,000 | $3,000 |
What drives the price
- Area
- Priced per square foot, but small jobs carry a minimum charge of a few hundred dollars because setup is the same regardless of size.
- Finished flooring above
- Carpet comes up cheaply. Tile has to be broken out and replaced, and hardwood is rarely salvageable — this can cost more than the subfloor.
- Joist condition
- Rot that reached the subfloor often reached the joists. Expect the quote to change once the floor is open.
- Access from below
- Over an accessible crawl space, some repairs can be done from underneath without disturbing the floor above.
Rot from below is a crawl space problem
A subfloor that has softened across a wide area, rather than around one fixture, is usually being damaged from the crawl space. Humid air meets the cooler underside of the floor, condenses, and the wood stays damp for months at a time.
Replacing it is the right repair, but it is half the job. Measure the crawl space humidity and deal with it — a vapor barrier, encapsulation or a dehumidifier — or the new subfloor follows the old one.
Common questions
- How much does it cost to replace a subfloor?
- Subfloor replacement costs $4 to $10 per square foot, or $1,200 to $7,000 for most jobs. A bathroom is $700 to $3,000, a 150 to 200 square foot room $1,200 to $5,000, and a whole 1,000 square foot floor $4,000 to $12,000. Removing and relaying the finished flooring adds $2 to $12 per square foot.
- Plywood or OSB for a subfloor?
- Both are acceptable and priced within a few dollars a sheet of each other — 3/4-inch tongue-and-groove sheets run $30 to $70. Plywood tolerates getting wet and drying out better; OSB swells at the edges if soaked. Over a crawl space or in a bathroom, plywood or a moisture-resistant engineered panel is worth the small premium.
- What causes a subfloor to rot?
- Water from above — a leaking toilet seal, shower pan or dishwasher — or moisture from below, which over a crawl space means high humidity condensing on the underside of the floor. Replacing a subfloor rotted from below without dealing with the crawl space humidity means replacing it again.
- Can I replace a subfloor myself?
- A small section, if you are comfortable cutting back to the centre of the joists and screwing and gluing new panels. Material cost is $2 to $4 per square foot. Larger areas, anything involving a toilet flange or plumbing, and anything where the joists are also damaged are better left to a carpenter.
How we price this. Figures are national 2026 estimates built from contractor quote ranges, material pricing and regional labour rates, then cross-checked against published industry cost data. Reckon Home does not sell, broker or perform this work. Use these numbers to judge whether a quote is reasonable — not as a quote.