Structural contractor (beam shimming): $280 - Sister joist materials: $45 - Subfloor screws: $18 - 1/4-inch plywood underlayment: $220 - Self-leveling compound: $85 - 2.25-inch solid red oak, #1 common (182 sq ft + 15% waste = 209 sq ft at $4.80/sq ft): $1,003 - Portanailer rental (2 days): $85 - To