QuestionA previous reader asked a question about tree routs causing problems to a house's foundation, you stated that the root system will turn when they reach a foundation and that if the foundation is not broken & leaking water the roots will not damage it.
Another reader followed up and said "A large poplar tree can transpire 150 liters of water per day during the summer. The water is taken up by the roots, thus depleting the soil of that moisture. Here lies the problem.. 80% of homes (Canada and U.S.) in urban settings, are built on expansive clay soil. When water is depleted from expansive clay,(it is extremely hard to replace) it shrinks a great deal, reducing the amount of friction that a foundation wall has in connection with the earth. When that friction is lost, there is very little to stop the foundation walls from buckling, heaving or cracking."
What type tress are considered a poplar tree? I live in NC, and I don't know about the type of soil that my house is built on but in light of this new insight, can you expand and/or comment further on your answer?
AnswerThere are several species of Popular tree. The poplar trees in North America are all members of the willow family. They include cottonwoods, aspens and balsam poplar. As such they usually grow in wetter soils. A common tree in NC is the Yellow-poplar,
Yellow-poplar (Liriodendron tulipifera) is common throughout the United States east of the Mississippi River. Although called "poplar" this species has no biological relationship to the true poplar genus, Populus. Poplar is a common name and to ID the tree it is best to use the scientific name which will let you know the real name. Common names are different for the same tree in different parts of the world.
The roots in my opinion if they are going to be a problem it will not depend on the soil type. The soil type may cause problem alone. Here is Al. we have a soil we refer to as black belt soil--heavy clay that will crack when it is in a drought situation. Red clay is added to the foundation site before the foundation is built to prevent this cracking but this has nothing to do with tree roots.
Large tree should not be planted next to the house since the roots near the trunk are larger and could push the foundation. IF a tree is planted this close the branch will be rubbing on the house causing more problems than the roots.
I am not sure if this cleared it up or not. I will stay with in general "that the root system will turn when they reach a foundation and that if the foundation is not broken & leaking water the roots will not damage it."
