5 Methods to Clear Tree Roots From Pipes

1. Rodding: Plumbers stick a ratchet (a bar with teeth) down your pipe to break up the root block. They then send another bar down to cut and clear the debris.
2. Jetting: Plumbers will use a hose with a special nozzle to direct a powerful jet of water at the block. With this method there is a big risk that the jet won’t be able to break up the blockage and you may have to pay for a more hard-hitting solution.
3. Root Cutting: This process uses the same high-pressure water as jetting, but in this case the water is more directed, and is used to cut the roots before flushing them out. Cutting the roots usually encourages new root growth and they could grow back faster and stronger.
4. Chemicals: This treatment is a heavy foam that contains herbicides. How a chemical treatment works depends on how bad the root block is. Less dense root masses can be forced out by the pressure of the foam as it travels down the pipe. More dense masses will have to be jetted first. The foam seals cracks in the pipes caused by the roots, and the herbicides hinder further root growth. You’ll have to treat pipes near root systems at least once a year by using Vaporooter; this is the leading product to get this done.
5. Dig out and Repair: This method requires excavation of the pipes and roots. Although fairly permanent, this method is often only used in extreme situations, such as the total collapse of a main drainage pipe. The costs can be quite high when you have to dig to remove tree roots.

Source: http://www.docstoc.com/docs/33520788/INVESTIGATION-OF-SEWER-BLOCKAGES-DUE-TO-TREE-ROOTS-Graham-Thomson-/