Concrete Tanks vs. Fiberglass Tanks

A concrete two tank system install.

A concrete two tank system install.

As in any industry the quality of products varies.  Alberta Septic & Excavating prefers to install concrete tanks rather than fibreglass or plastic tanks for many reasons.  Concrete tanks do not require specialized imported back fill material keeping the cost of installation down.  Fiberglass or plastic tanks usually require a layer of sand or pea gravel completely surrounding them to protect them from damage.  Concrete tanks will not float if there is water in the bottom of the hole when being installed.  Furthermore, because fibreglass tanks are light they are more susceptible to floating if there is a high water table when the vac truck cleans them out.  They are like an inflated balloon in the ground when empty and can pop up even after they are back filled.  Fibreglass tanks often need to be anchored with concrete.  Concrete tanks can be buried deeper avoiding the need and additional cost of lift stations.  Nine foot basements are popular these days which often requires a deeper septic tank.  Manufacturer’s of fiber glass tanks will claim that they are more resistant to sewer gas but sever gas is extremely corrosive and given enough time it can still cause deterioration.  See the picture below.  In addition, although no tanks should be driven on, in the event that this does happen concrete tanks are less likely to sustain damage.

Removing a fiberglass tank that cracked due to hydraulic pressures.

Removing a fiberglass tank that cracked due to hydraulic pressures.

Sewer gas damage to a fiberglass tank lid.

Sewer gas damage to a fiberglass tank lid.

A plastic tank we removed with major damage after a post was pounded through the top.

A plastic tank we removed with major damage after a post was pounded through the top.

Advertisement

3 thoughts on “Concrete Tanks vs. Fiberglass Tanks

  1. Glad I read this, my new installation was recommended the fiberglass tank, I have never heard of one so I was reading up on them. I have always had concrete tanks and have one now which is over 30 years old and no problem. Think I will get another company to install this system who uses concrete.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s