CSST underground installation requires what regarding marker distance from grade?

• A. Marker placed twelve inches from grade
• B. Marker placed six inches from grade
• C. Marker not required
• D. Marker placed at grade level

Answer: (B)

The main idea here is that buried gas piping must be clearly identified so future excavation doesn’t strike it. For CSST underground runs, the marker should be placed six inches from grade, meaning six inches above the ground level. This offset helps ensure the marker stays visible even if soil settles, mulch is added, or grading occurs, and it prevents the marker from being buried or easily damaged. Placing a marker at grade level risks it being buried or obscured, while six inches above grade strikes a practical balance between visibility and protection. The option of not requiring a marker is incorrect because marking buried gas lines is a standard safety practice.