Trees Too Close to Foundation

I look at houses all the time that have mature trees and bushes growing too close to the foundation.  Trees and bushes will remove moisture from the soil, and if they're removing moisture from underneath or adjacent to the foundation, the foundation could experience some distress from the movement of the soil.

A mature oak tree can remove over 100-gallons of water per DAY!  That's a lot of water.  Since expansive soils shrink and swell depending on their moisture content, you can easily see how trees can wreak havoc on a foundation.

Generally speaking, if a tree's dripline (i.e. the edge of its canopy) is overhanging the house, then the tree's roots are extending far enough out from the trunk that it could be pulling moisture out of the soil from underneath the slab.

In the picture, that oak tree is only a few feet from the slab.  There were two cracks in the brick veneer adjacent to the tree, as well as some cracked floor tile just inside the house in the vicinity of the tree.  The cracks in the brick and the floor tile were likely caused by the tree removing moisture from the soil underneath the slab, causing the slab to move and crack the brittle finish materials.

Also note how the dripline extends way over the roof.

If you have trees and large shrubs next to your foundation, but the trees and shrubs seems to be getting along well with the slab, then there may be no need to do anything.  Sometimes removing a large tree can cause more problems than leaving it in place.  A lot of that depends on the visible damage that the tree is causing.

If you do decide to remove a tree, keep in mind that the soil is going to go through a period of rehydration, which could cause the soil to swell and the foundation to move.

If removing a tree is not desirable, the installation of a root barrier may help to mitigate the impact the tree is having on the foundation