Our Unique Polyethylene Green Sleeve

Let’s look at one feature that makes Techno Metal Post stand out from our competitors: Our high-density polyethylene green sleeve. It offers a unique benefit because of its design to reduce friction between the surrounding soil and the helical pier.

For over 30 years now, Techno Metal Post has promoted using the green sleeve during the installation of helical piers, particularly for those installed through a layer of soil subject to freeze/thaw cycles. When the ground freezes, it causes the soil to expand and push the ground surface upwards, resulting in frost heave. Expansive soil can also alternate between shrinking and swelling with seasonal changes in its moisture content.

Over time, we observed that using the green sleeve reduces the risk of piers lifting/heaving in winter and thus promotes their stability throughout the seasons.

During 2020, TMP undertook a process to characterize and quantify the positive effects related to the use of the green sleeve. A field load test campaign was completed in March 2022 by TMP and witnessed by a third-party laboratory. The objective was to validate the effectiveness of the green sleeve on our helical piers, models P1 to P5, for two different types of soil (compact sandy silt and stiff clay silt).

The test consisted of conducting pull-out load testing on pier shafts installed with and without a green sleeve. Based on the analysis of different results, the conclusion showed that friction can be reduced on average by 67% between the pier with a green sleeve and the frozen ground.

Important to note: Normally, helical piers are designed to be anchored in a stable layer of soil and installed below the frost line or zone of potentially swelling soil. Helices in a deeper soil layer resist uplift forces caused by frost or expansive soil. However, for shallow applications of light loads, such as deck foundations, patios or other residential structures, we recommend our high-density polyethylene green sleeve to reduce the effects of soil friction and expansive soil.

Overall, adding the polyethylene green sleeve during a pier installation greatly reduces the risk of piers lifting/heaving in winter and allows the stability of your structure on a long-term basis.

Call your local dealer if you have questions, they will be happy to chat with you and take the time to explain the benefits of our technology. Click here to contact a dealer.