Screw piles for piers

Why screw piles are chosen for piers

1. Strength and stability in soft soils

The bottom soil is rarely dense. Along the banks of rivers and lakes, there is silt, sand, or clay. Driving concrete or wood into these areas is pointless: they are "drift," squeezed, and sink. A screw pile, on the other hand, is screwed into a dense layer below the loose bottom soil—approximately 1.5–2 meters. The blade acts as an anchor, firmly securing the pile even in a shifting environment.

Simply put, a screw pile is held in place not by its weight, but by its grip on the ground.

2. Water and frost resistance

Unlike concrete, which absorbs moisture and cracks when frozen, piles are protected by an anti-corrosion coating. A zinc coating or epoxy paint insulates the metal from contact with water. Even when the soil freezes and thaws, the pile maintains its strength—it "plays" with the soil movement without deforming.

3. Minimal impact on the ecosystem

Helical piles are installed by screwing using hand tools (requiring 2-3 workers) or specialized hydraulic equipment with a gearbox. This technology differs from driven piles in that it minimally disturbs the structure of the bottom soil—the blades are carefully screwed into the ground without compromising its load-bearing capacity.

Properly selected blade configuration preserves the integrity of the surrounding soil and avoids significant deformation of the reservoir bottom during the construction of piers, walkways, and other hydraulic structures.

4. Quick and clean installation

Installing piles for a pier takes 1-2 days, depending on the length of the bridge. The work can be performed year-round, even in winter, while ice remains. The decking can be assembled immediately after the piles are installed, without waiting for the concrete to cure.

What types of piles are used for piers and walkways?

A pier, unlike a typical canopy or terrace, is constantly in contact with water, so the requirements for piles are more stringent. An incorrect diameter or coating can lead to deck warping or corrosion within a couple of years.

Diameter and Wall Thickness

For piers, reinforced piles with thicker walls and larger blades are used. This prevents the pile from loosening in currents and from "wandering" during seasonal soil movement.

Material and Corrosion Protection

Piles for water structures must be made of steel grade no lower than ST20 and treated with anti-corrosion compounds. The best options are:

1.       Hot-dip galvanizing – forms a durable zinc layer that is not washed away by water.

2.       Epoxy or polyurethane coating – creates a sealed film that protects against oxygen and salts.

3.       Combined protection—zinc and paint—is the most reliable option for aggressive environments.

For particularly humid conditions, stainless steel piles or polymer-coated pipes are used, but their price is 2-3 times higher than standard piles.

Capitals and Supports

Special caps with anchor pads or U-shaped grips for wooden beams are installed on the piles. This allows the decking to be secured directly above the water and the height to be adjusted as needed.

In areas where the water level fluctuates, adjustable supports—piles with retractable telescopic elements—are sometimes installed. This is convenient for seasonal piers that need to be raised in the spring and lowered in the fall.

Pier Piling: Construction Stages

1. Site Marking and Preparation

First, the pier axes and future pile installation locations are determined. Marking is done from the shore using a level and cords. It is important to consider the depth, slope of the bottom, and water level during different seasons.

If the pier extends far from the shore, a floating craft (such as a pontoon or boat) is used to attach a post with markings.

Stage 2. Screwing in the Piles

Piles are installed in two ways:

•        From the shore: the first section of the pier is assembled directly on dry land, and as the work progresses, workers move onto the finished deck, screwing in the subsequent piles.

•        From the water: if the depth is more than 1.5 meters, a boat or pontoon with a hydraulic winch is used.

Hole piles are screwed into a dense soil layer that is not easily washed away by the current. Typically, this depth is 1.5–2.5 meters. After screwing in, each support is checked with a level and load.

3. Leveling and Trimming

After installation, the piles are trimmed to the level of the future deck. An anti-corrosion coating is immediately applied to the cut surfaces—this is especially important in areas exposed to water and air.

Concrete is poured into the pile—it protects the metal from the inside and makes the support rigid.

4. Installing the pile caps and assembling the deck

The pile caps are welded or screwed onto the prepared piles. Next, the load-bearing beams are installed—usually made of galvanized profile or larch if the pier is wooden.

After this, the decking is assembled: planks, deck tiles, or lattice metal. It is important to provide gaps for water drainage and to compensate for the seasonal expansion of the wood.

5. Inspection and Final Finishing

After assembly, the pier is checked for stability and levelness. All welds are additionally coated with a zinc-containing spray or mastic. If necessary, the bottom of the piles is treated with a special bitumen paste that is water-resistant.

The result is a durable structure that can easily withstand ice, waves, and the weight of several people without the slightest deflection.