Step 2 · Support the Existing Pipe
Cast iron pipe is extremely heavy. Before cutting, you must securely support the pipe on both sides of the planned cuts. Use adjustable pipe hangers secured to the floor joists above, or build supports using wood blocks (e.g., 2x4s). Place one support within 12-18 inches of each side of the section you plan to remove. This prevents the remaining pipe from sagging, breaking at the next joint, or falling on you.