Question
We have a huge and old Maple tree (belongs partly to the District) that sits about 12 feet away from the front of our house. Over the last few years, we have noticed that the roots of this tree are very visible from the surface of the ground and some of the roots are touching the base of our house. We spoke to our district arborist and was told by him that the roots are not affecting the foundation of our house. I find that very hard to believe and my other consern is the underground pipes too. We would really appreciate your opinion. Thank you for your time.

Answer
Tree roots have a spread width of about 1 /1/2 times the branch spread. Larger roots can damage foundations if the tree is close to the house. IF the house is a crawl space type house the roots usually are not a problem but could be if the house is on a slab type foundation. IF the tree is that old it more than likely is not harming the foundation since the roots more than likely have adapted and turned away from the foundation. Water pipes will not be damaged by tree roots since the pipes are sealed and the roots can not get to them. Roots tend to grow toward moist soil and if there is a leak they would grow that way. Septic tank lines can be damaged by roots since they are not as sealed as water pipes since there is little water pressure in theses pipes. Tree roots can and do damage septic lines and can be problem. A large maple tree 12 feet from the house could be a problem from the limbs hitting the house. Limbs reaching the house should be pruned off to keep from them rubbing the house.