The
most important feature of a septic system is the buried tank, which contains
wastewater as it moves out of your home. Despite the heavy-duty nature of this
tank, it remains susceptible to damage if not cared for properly.
Cracks
are the most common form of septic tank damage. A crack allows wastewater to
escape from the tank, which creates potential health hazards. If you would like
to learn more about the factors that can lead to a damaged septic tank, keep
reading. This article takes a closer look at three common causes of septic tank
cracks.
One
of the most common causes of septic cracks involves vehicles driving or parking
directly on top of the tank. Even when buried below several feet of earth, a
septic tank simply cannot handle such compressive forces. Not only can the
weight of a car crack a septic tank, but it can also cause a weakened tank to collapse
entirely.
Be
sure to learn the exact location of your septic tank, and never drive or park
cars in that vicinity. Those who simply cannot avoid placing a septic tank
along a driveway or road must select an appropriately reinforced tank. A septic
professional can help determine which tank design offers the necessary
top-loading strength to resist vehicular damage.
Some
concrete septic tanks consist of preformed concrete blocks mortared together.
Other tanks consist of fresh ready-mix concrete poured into forms and cured
on-site. In the latter case, the exact proportions of the concrete mix play a
huge role in determining the long-term structural stability of the tank.
The
water-to-cement ratio of your concrete mix should never exceed 0.45. Above that
level, the curing concrete experiences excessive amounts of bleeding — in other
words, water rising to the surface of the concrete.
A
high bleed rate increases the amount of capillary pores in the concrete. These
void-like pores allow water to flow into and through the concrete. This
porosity presents problems for long-term durability, especially for those who
live in regions with cold winters. As water trapped in the concrete freezes, it
expands, which creates pressure that can easily crack the concrete.
A
low water-to-cement ratio improves the watertightness of the concrete, which
protects it from damage due to expansive forces.
The
ground around your septic system can also lead to a cracked tank, especially
for those whose soil contains a high clay content. These expansive soils can
absorb much greater amounts of water than regular soil. As a result, expansive
soils undergo proportionally larger volume changes than regular soil.
As
expansive soil soaks up water and expands, it exerts increasingly greater
amounts of pressure on the walls of your tank. This pressure can easily cause
cracks to form. Expansive soil also becomes problematic during especially dry
periods, when it shrinks out, pulling away from the walls of the tank and
leaving it undersupported.
At
such times, the weight of the wastewater can create large enough amounts of
stress to crack the walls of the tank. Preventing damage due to expansive soil
begins with proper septic system planning. Ideally, a professional should
install a septic tank with the requisite strength to withstand expansive
forces.
Homeowners
can also protect pre-existing tanks against expansive soil by practicing smart
water management. Landscaping should direct water away from septic tanks
whenever possible. During dry seasons, you may need to take the opposite
approach, which ensures that your yard remains well enough hydrated to prevent
excessive shrinkage.
For
more information about how to protect a septic tank from cracking, contact the
industry pros at The Nibbler Company.
