That beautiful tree is destroying
your property: The magic of how tree roots grow
Not all trees have damaging root systems, but it is worth
understanding how roots grow and especially if you’re planning on planting a
tree, knowing what to look for to avoid problems in the future. Let’s first
talk about different trees.
Maple, ash and cottonwood trees have lateral root systems
that are known to be invasive and are not good choices near foundations. Pine
trees, oaks, walnut, hickory and conifers are tap root feeders – their root
systems grow straight down into the ground and have almost no effect on home
foundations.
Hardwood trees like elm, oak and ash have shallow root
systems. These trees grow quickly because they use plenty of water and have
root systems that fan out slightly farther than the edge of their leaf mass.
Whether these root systems will damage a foundation depends greatly on the
soil.
On what type of soil is your home built? Gravels, sands and
silts that are dry and well-compacted may not be impacted by trees at all. The
tree will pull water from this soil however, little volume loss of soil mass
will occur. In loose soil however, roots will seek out moisture and can cause
shifts in soil and bring instability to a foundation, causing it to shift. When
trees are planted close to a house foundation when a house is constructed,
roots will weaken the surrounding soil simply through its survival, causing the
foundation to ‘settle’.
There are two ways that homeowners can attempt to control
damage a tree’s root system can inflict on their foundation.
Control the leaf mass – a tree’s
leaf is the way in which water is dispersed back into the atmosphere. By reducing
the number of leaves, the less water the tree will use. It’s worth noting that
removing too many leaves can kill a tree, so use caution.
Manage the root growth away from
the foundation – the general rule from experts is that trees should be planted
no closer than half of their anticipated mature height toward the foundation.
So for a tree that grows to be 40 feet tall, it should not be planted within 20
feet of a foundation.
Hopefully this gives you some idea about the damage roots
systems can cause to your home’s foundation. Whether you’re planting a new tree
or taking inventory of the trees surrounding your property, a professional tree
service or arborist can help further educate you about protecting your
foundation as well as caring for your trees.
