Here's the deal. If you have clay, cast iron or other piping with flexible joints, and trees around, then you need to have the main line either snaked every year to prevent root growth or use a root destroyer every 6 months after an innitial cleaning. If you do this type of maintenance, you won't have to pay for a new line when the tree roots destroy your piping. Remember, tree roots are strong enough to get into tiny fissures in rocks and break them apart after years of growth. Your pipes (clay and cast iron) are weak compared to rock. A little maintenance will save you a lot of headaches. Now if your pipes are plastic and the joints are glued, you should have no worries as long as they are pitched properly.

Good Luck

Raymond VinZant Plumbing Prof.