Question
I have a beautiful 30 ft river birch off my back patio.  It is 12 ft from the house at the nearest point.  The house is built on a concrete slab.  What do I need to do to protect the foundation?  Is cutting roots that grow near the house enough?  Would cutting roots on one side make the tree more likely to fall toward the house in case of storm damage?  Thanks for any advice!

Answer
The roots will spread about 1 1/2 times the width of the branches and be mainly in the first 2 feet of soil. At maturity the branches could have a spread of 20-30 feet. You should not have a problem with root damage from a river birch--their root system is fibrous and I could find no one who has sited root problems with this species. As the tree grows the limbs may rub against your house causing problems but this can be solved by pruning back the limbs. When you prune the branches do it during the winter --birch has a tendency to seep sap at the wounds and this could attract a birch borer. In the winter the sap is not flowing much and the wound can heal some what before the spring sap starts.