The quest to find longer lasting, lower maintenance building materials is endless, especially in the marina industry where salty seas, ice, extended exposure to sun, and relentless wave action are strong contenders in the battle of man versus nature. Constant exposure to the elements in the marine environment can attack even the strongest of materials.
A fairly recent advancement in the industry that boasts product longevity is the high-density polyethylene (HDPE) pile sleeve, used to protect steel as well as timber pile. The sleeve is an alternative to traditional treatment methods and is proving to be a viable option for marinas looking for a pile that is longer lasting and requires less maintenance.
Bellingham Marine has been using HDPE pile sleeves over steel piles successfully with concrete floating docks in Australia for over a decade and more recently in the Caribbean and the U.S. While the technology is still relatively new, proponents of the HDPE pile sleeve claim that the protection given by the thick plastic barrier is long lasting. The strength in the performance of the sleeve comes from the fact that once the initial oxygen contained beneath the sleeve is consumed, the metal’s ongoing exposure to oxygen is limited to only that which exists in the soil – without ample exposure to oxygen the rate of corrosion is greatly reduced.
The sleeve is ¾ – 1 inch thick and is embedded approximately 2 feet below the mud line. Even if nicked or scratched the protective barrier offered by the sleeve will not be compromised. On the other hand, galvanized or epoxy coatings are typically only 1/16 inch thick. The thin protective layer does a decent job of protecting the pile initially but is extremely vulnerable to small scratches or nicks.
On average, industry experts estimate that a galvanized or epoxy coated steel pile has 8 – 10 years before it will require constant maintenance and up keep. These piles typically have a lifespan of 30 years. In comparison, an HDPE sleeved steel pile is estimated to have a lifespan of 50 – 100 years and will require no maintenance whatsoever.
The HDPE sleeve not only offers the benefit of longevity but offers cosmetic and environmental benefits to the marina as well; the look is clean and uniform, and it will not leach chemicals or negatively impact the water quality.
The sleeved pile is also relatively easy to install. Once the pile is driven, the HDPE pile sleeve is driven over top of the pile and embedded into the ground. An HDPE cap is then welded on top of the sleeve creating an oxygen barrier and sealing the pile in an airtight sleeve. It is important to note that the sleeve must be a tight fit to perform as designed.
Bellingham Marine is committed to helping owners build profitable and lasting structures. For additional information about this innovative option please contact us at bmi@bellingham-marine.com
