Verify Overall Frame Squareness, Plumb, and Level

What happens here

With all major components in place, conduct a thorough check of the entire stair frame. Use a long spirit level to verify the overall levelness of the treads and the plumb of the stringers. A large framing square or the '3-4-5' method with a tape measure should be used to check diagonal measurements across the frame openings to confirm squareness. Adjust any components as necessary by shimming, slightly repositioning, or adding temporary bracing. This critical verification step ensures structural integrity and proper function before any permanent fasteners are applied.

Goal: Perform final adjustments and verification of the entire stair frame to ensure it is plumb, level, and square using various measuring and leveling tools.