Step 4 · Frame the Floor

Cut floor joists (e.g., 2x6s or 2x8s) to size. Attach them to the foundation skids or build a frame that rests on the foundation blocks or slab. Ensure the joists are spaced correctly (typically 16 inches on center) and are square to the rim joists. Once the frame is complete and square, lay down and secure the subflooring material (e.g., 3/4-inch exterior-grade plywood or OSB) using screws or nails.