Trees and Shrubs

Trees and Shrubs

The roots of trees and shrubs can affect footings by removing moisture from clay soils immediately underneath the building, causing subsidence as the clay shrinks.

In its search for water, a tree root system can spread a lateral distance equal to the height of the tree. If in rows or grouped with other trees, the roots may spread up to twice the height of the tree.

Care should be taken when selecting trees. As a guide, the trees listed below should not be planted within the distance of their mature height from the house depending on the site classification and whether they are planted in a line or in a group.

Height of Tree (h) – Distance from house (d)
d = 1 × h for class H and M sites.
d = 1.5 × h for class E sites.
d = 2 × h for rows or groups of trees.

Approximate Tree Heights