Are Galvanized Screw Piles a Gimmick?

Competition: “We offer no gimmick screw piles.  Don’t pay for things you don’t need such as hot-dip galvanizing.”

What else is the competition going to say when they can’t offer hot-dip galvanized screw piles at an affordable price?

Postech Screw Piles has made a commitment to quality and one area we push heavily is hot-dip galvanized screw piles.  As a result they send a lot of our helical screw piles (like 98%) for hot-dip galvanizing.  You can likely appreciate that the volume discount received is substantial and therefore Postech dealers can offer a top-quality hot-dip galvanized screw pile at an affordable price.

TIP:  Compare pricing before assuming you’re paying too much for hot-dip galvanized screw piles.

Here is a chart demonstrating the difference in screw pile with 1/4″ wall thickness life expectancy between black steel (untreated) and hot-dip galvanized steel.

Corrosion of Screw PIles Chart

1st value in Italics = Minimum Life Expectancy   

2nd value in Bold = 98% Probability of Life Expectancy

3rd value Normal = Average Life Expectancy

Source:  “Helical Piles: A Practical Guide to Design and Installation”, Howard A Perko (2009)

As you can see, hot-dip galvanizing will more than double the life expectancy of a screw pile.

In Manitoba, most soils will fall under high or moderate corrosivity.

Well doesn’t the galvanizing just scratch off?

When the soil has debris or rocks in it, that is where the key advantage of galvanizing is realized.  Galvanizing provides a tough, impermeable coating. Physical damage is still possible (pile hitting or rubbing on rocks), but even when the coating is scratched through to bare steel, it will continue to provide cathodic protection to the exposed steel.  Even a 1/4″ wide scratch to bare steel  will be protected by the surrounding zinc until such time the zinc coating has corroded off the steel.  That doesn’t happen with paint and non-treated metal corrodes faster when scratched.

“Coating damage is most likely to occur at edges and often corrosion begins in the interior of hollow structures, so these areas are where added protection is needed.” – American Galvanizers Association

A hot-dip galvanized screw pile is coated on all surfaces including the interior of the shaft and at the edges.

It is also important to note that Manitoba’s clay soils are typically free of debris and galvanized coatings are usually fully in tact after installation.

If you would like to know more about corrosion of Postech Screw Piles, please contact Dale Plett, Director of Customer Consultation at Postech Screw Piles Manitoba and NW Ontario and request a copy of a technical brief – 204.793.0653 or

Visit our website at



About screwpiling

We install premium pile foundations which are guaranteed against movement due to frost heaving. Our piles are affordable and professionally installed according to torque, this means you get a perfect install every time! We proudly serve the Greater Winnipeg Area, Steinbach, South-East Manitoba and Interlake regions. Start off on a solid foundation with a Postech Thermal Piles, the most solid and stable piles ever designed.
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