Prepare and Level the Base

What happens here

Achieving a perfectly level base is crucial for the long-term stability of the stairs. Use a level to check each block from side to side and front to back. Then, check the level across multiple adjacent blocks to ensure an even surface across the entire foundation. A small 'lip' (slight height difference between blocks) is acceptable within tolerances, but anything larger will lead to future problems. The subsoil (raw earth) and base material (such as 3/4 clear rock or Class 5 aggregate) beneath the blocks must be thoroughly compacted to prevent settling. If the subsoil is soft or 'squishy,' it should be removed and replaced with good, compacted base material.

Goal: Ensure the base for the stairs is perfectly level and compacted.