Install Subfloor Sheathing

What happens here

Begin installing subfloor sheathing (typically OSB or plywood) over the laid joists. Carefully center the subfloor sheets on the center of the joists to ensure adequate nailing surface for adjacent sheets. Crucially, stagger the seams of the subfloor sheets; do not let seams fall on the same joist in adjacent rows. Staggering helps to spread loads across multiple joists, enhancing the overall strength and stiffness of the floor and preventing load concentration on a single joist. Before fastening, apply a continuous bead of subfloor adhesive (e.g., Liquid Nails) to the top of the joists to prevent squeaks and further bond the subfloor to the framing. Then, use a screw gun to securely fasten the subfloor sheets to every joist, ensuring the screws are properly spaced and sunk below the surface. Measure out your studs (wall framing) on the subfloor as you go to maintain accurate layout for subsequent construction.

Goal: Create a solid, stable, and squeak-free walking surface over the joists.