Here are a few things to try:

Chemical Root Killers: There are chemical root killers available at hardware stores specifically designed to kill tree roots that intrude into sewer lines. These products contain copper sulfate or similar substances that can inhibit root growth. Follow the manufacturer’s instructions carefully when using these chemicals.

Hydro Jetting: Hydro jetting is a method that uses high-pressure water to clear and clean sewer lines. It can help remove tree roots and other obstructions from the pipes. This is typically done by professionals with specialized equipment.

Mechanical Root Cutting: Professional plumbers often use mechanical root cutting tools, such as a sewer auger or rooter machine, to physically cut and remove tree roots from sewer pipes. This method is effective for immediate removal of roots, but it may not prevent regrowth.

Chemical Foaming Agents: Some foaming agents are designed to coat the inside of sewer lines with a root-inhibiting chemical. These products can help prevent root intrusion for a period of time.

Trenchless Repair: In some cases, it may be necessary to repair or replace sections of your sewer line that have been damaged by tree roots. Trenchless sewer repair methods, such as pipe lining or pipe bursting, can be used to address root infiltration without extensive excavation.

Regular Maintenance: To prevent future root intrusion, consider scheduling regular sewer line inspections and maintenance. This can help detect root problems early and take preventive measures.