The weather is warm and rain abundant, and tree roots are
trying to break into your
house.

For most well-designed and -installed foundations,
sidewalks and driveways, roots can’t
breach your spaces. But some poor designs actually encourage
tree roots to grow, leading
to structural damage.

We’re surrounded by a hardscape of cement, masonry and
asphalt. Within this hardscape
are sewers, water pipes and utility lines that bring quality
to our lives.

These hardscapes are built to withstand occasional
natural calamities and constant use
by humans and vehicles. But they’re sometimes vulnerable to
other natural attacks.

Many sidewalks, driveways, patios and foundations are
designed and installed properly
for human use but ignore the valuable trees in the area.
They aren’t designed to withstand
slow-acting natural processes. And opportunistic tree roots
use these engineering flaws.

Many homeowners and engineers blame tree roots for
cracking sidewalks and damaging
foundations. Irreplaceable trees have been permanently
damaged or removed to minimize
damage to a piece of concrete. But the trees are just the
scapegoats for faulty design,
engineering and maintenance.

We often invite tree roots into the hardscape surrounding
us. The ways we design and
build things leave gaps, pores and spaces for tree roots to
use.

The coarse sand beneath a sidewalk is an open invitation
for roots to grow and crack
the cement. Without proper soil compaction or protective
barriers, roots will colonize
areas near pipes, foundations and pavements.

Roots aren’t the main cause of damage to hardscapes.
Through careful disregard, their
roots are invited into warm, moist, protected places with
plenty of oxygen and space.

With a full cookie jar left open in the play room, a
child may be blamed (or even
punished) for cookie indiscretions. But better solutions are
clearly present.

Tree roots are made to use soil pores and control space.
Providing more space for root
systems is the same as providing more resources for the
tree. Roots are designed to
carefully sense current soil conditions and, in concert with
the rest of the tree, exploit
open spaces.

As roots explore and colonize soil space, they come into
conflict with other
structures. These conflicts are most often associated with
sewer or septic lines, storm
water drains, water supply lines, foundations, sidewalks,
streets, parking lots, pavements
(floating and with footings), curbs, walls, swimming pools
and structures on dimensionally
unstable soils.

Most of these conflicts are preventable.

If we understand trees’ growth and correctly install
structures made of proper
materials, we can minimize tree root damage. Ignoring the
way tree roots grow will allow
trees to remain an excuse for poor workmanship, bad
development, ignorant designs and
incompetent engineering.

Tree roots take advantage of cracks, pores and gaps in
building materials. They can’t
push into pipes. But they can take advantage of small cracks
and improperly sealed joints
and connections. They can’t break up cement. But they can
raise pavements where foot
traffic can form cracks. Tree roots can’t grow into a solid
foundation. But they can grow
into settling cracks caused by other problems.

Some tree-illiterate designs inadvertently prepare a
great home for tree roots. When
the roots move in and start to elongate and grow in
diameter, any fault can be expanded.

Don’t blame trees for human errors. If you don’t want
tree roots, don’t invite them in.