Subfloor Repair Cost Estimator
Estimate the total cost to repair or replace damaged subfloor based on area, damage severity, material choice, and local labor rates.
Formula
Damaged Area = Room Length × Room Width × (Damage % ÷ 100)
Material Needed = Damaged Area × (1 + Waste % ÷ 100) × Damage Severity Material Multiplier
Material Cost = Material Needed × Material Unit Cost ($/sq ft)
Labor Hours = Damaged Area × Labor Hours per Sq Ft (by severity)
Labor Cost = Labor Hours × Labor Rate ($/hr)
Supplies Cost = max(Material Cost × 8%, $25)
Subtotal = Material + Labor + Removal + Joist Repair + Supplies
Total Cost = Subtotal × 1.10 (10% contingency)
Cost per Sq Ft = Total Cost ÷ Damaged Area
Labor hours per sq ft by severity: Minor = 0.05 hr, Moderate = 0.10 hr, Severe = 0.18 hr.
Minor damage uses only 30% of material quantity (patch compound vs. full panel replacement).
Assumptions & References
- Material unit costs are national averages (2024): OSB $0.65/sq ft, Plywood 1/2" $0.90/sq ft, Plywood 3/4" $1.20/sq ft, Concrete patch $2.50/sq ft (HomeAdvisor, RS Means).
- Labor rate default of $65/hr reflects mid-range U.S. carpenter/handyman rates; adjust for your region ($45–$100/hr typical).
- Floor covering removal costs: carpet/vinyl ~$1.00/sq ft, hardwood/tile ~$2.50/sq ft applied to full room area.
- Joist sistering flat costs are estimates: 1–3 joists ~$150, 4–8 joists ~$400, 9+ joists ~$900 (materials + labor).
- A 10% waste factor is standard for rectangular rooms; use 15–20% for L-shaped or irregular layouts.
- A 10% contingency is included for unforeseen conditions (hidden rot, fastener issues, subfloor leveling).
- Estimate does not include permit fees, mold remediation, or finish flooring reinstallation.
- Sources: HomeAdvisor Cost Guide, Angi Subfloor Repair Costs, RS Means Building Construction Cost Data 2024.