We have a spruce or fir tree which came up on its own, about 10 inches from
the foundation of our house. At first it seemed to be just a shrub, but it's
now grown into a tree about 30 feet high.

We like the tree, but we're concerned that the root system may endanger the
foundation, much the way that tree roots sometimes cause sidewalks to buckle
up.

Is this a danger?