Dock Piling Installation: A Step-By-Step Guide For Boaters

Dock pilings are an essential component of any waterfront structure, providing stability and support for docks, piers, and other watercraft. Installing dock pilings can be a challenging task, but with the right tools and techniques, it can be accomplished successfully. One common method is jetting, which involves using a high-power water pressure hose to dig a hole in the soil and then sinking the piling into it. This process requires at least two people and is suitable for sandy or soft soil. Alternatively, pilings can be set in concrete footers, which provides more stability for muddy beds. When installing pilings, it is important to consider the weight of the dock, the number of pilings required, and the soil conditions to ensure the structure is secure and safe.

Using a water jet to clear sand and silt

To use a water jet to clear sand and silt, you will need to follow these steps:

• Obtain your pilings, ensuring they are chemically treated to prevent water damage and are long enough to reach the dock above the water line after being driven a minimum of 4 feet into the soil.
• Set up your water pump so that the suction hose is in clean water and will not be disturbed by the jetting. The discharge hose needs to be long enough to reach the bottom of the hole at the furthest pile from the shore.
• Mark your jetting pipe and pile with index marks so that they can be kept at the same level while you are setting the pipe. Attach an elbow at 90 degrees to the end of your jetting pipe to direct the water underneath the piling as you drive it down.
• Stand the first piling in the water and push it into the lakebed. If possible, recruit 1-2 strong people to help you hold the piling in place.
• Aim the water jetter at the bottom of the piling and turn on the pump. The water will blow out of the hose with enough force to push the sand and silt out from under the piling. As this is happening, guide the piling further down into the earth until you reach the desired depth. Move the tip of the hose from side to side so the piling can go in evenly.
• Once the pile is in place, strap it to the dock with a rope or bungee cord and use a spirit level to make sure it is true.
• Use the water jetter to push some of the dirt back into place around the piling after it’s set. This helps stabilize the piling.
• Repeat this process for the remaining pilings.

This process will require at least two people to hold up a 12-foot by 8-inch piling; anything larger will require a crane. It is also important to wear protective gear to prevent injury.

Pouring concrete posts

Concrete dock pilings are a popular choice for commercial and industrial use due to their durability, longevity, and strength. They are made of reinforced concrete, which is a mixture of cement, aggregates, and steel reinforcement. Before you begin, ensure you have the necessary tools and materials, including heavy-duty PVC pipe, quick-set concrete, a post-hole digger, and a water pump or hose.

To pour concrete posts, start by measuring the length of PVC pipe needed for each piling. Measure from the lakebed to the highest water level, adding an extra 1-2 feet if the lakebed is soft. Purchase heavy-duty PVC with a diameter of 12-18 inches for standard 8-foot docks. For longer docks, opt for a larger diameter PVC pipe and posts.

Next, drive the PVC pipe about 2 feet into the lakebed. You can do this by hand or use a spare piece of wood and a sledgehammer. Mark the pipe in 1-foot increments to monitor its depth. Once the pipe is in place, remove any water, mud, or silt from inside the pipe using a bucket and a post-hole digger.

Now, it's time to mix your concrete. Follow the instructions on the package to mix the quick-set concrete in buckets. The amount of concrete needed depends on the size of your project. For a standard 12-inch diameter PVC pipe and a 4-inch post, estimate about 2 bags of concrete per foot of height.

With your concrete ready, pour 10 inches of concrete into the pipe. Then, insert your wood post and push it down into the concrete mix. Continue pouring concrete around the piling until you reach the maximum waterline. Ensure you work slowly to avoid air pockets in the concrete.

Repeat this process for each post, and then let the concrete cure for 3-4 days. It's important to be patient and allow the concrete to cure completely before continuing with your project.

If you have a lakebed that is extra sandy or soft, you may need to go deeper than 2 feet with your PVC pipe. Additionally, always check local regulations regarding dock or pier construction, as permits may be required.

Using pressure-treated wood pilings

Pressure-treated wood pilings are a great option for your boat dock as they are sturdy, high-quality, and long-lasting. Treated wood pilings are more affordable than other options like fiberglass and Greenheart wood, and they can also withstand immersion in brackish or saltwater while maintaining their integrity. The treatment process involves fortifying natural lumber against mould, rot, and pest infestations by exposing the wood to a chemical treatment under pressure. Here are some detailed instructions on how to install pressure-treated wood pilings for your boat dock:

Step 1: Choosing the Right Wood

Select round dock pilings made of pressure-treated wood. The treatment process preserves the wood with special chemicals that help it withstand harsh outdoor conditions, such as constant water exposure and attacks by marine organisms. Round pilings are harder than square-cut ones because they are not cut to expose the interior of the wood. Pressure-treated wood is also the most cost-effective option.

Step 2: Determining the Diameter and Number of Pilings

The diameter of your pilings will depend on the weight of your dock. If your dock weighs less than 10,000 pounds, choose pilings with a diameter of 6-8 inches. For docks weighing more than 10,000 pounds, select pilings with a diameter of 10-12 inches. Ensure you have enough pilings to place one about every 10 feet along both sides of the dock for adequate support.

Step 3: Preparing the Pilings

Spray paint your pilings at 12-inch intervals to monitor their depth during installation. Cut the pilings to the appropriate height, taking into account the desired height of your dock above the water level, as well as the depth of the pilings underground (4-6 feet). The ideal height of your dock should be above the highest water level, accounting for tides, flooding, or heavy rainfall.

Step 4: Installing the First Piling

Stand the first piling in the desired spot in the water. If possible, enlist the help of one or two strong individuals to hold the piling in place. Once it is in the right location, gently push or hammer it a few inches into the lakebed for initial stability. If the lakebed is hard or compact, use a water jetter to create a starter hole to help the piling settle.

Step 5: Using the Water Jetter

Aim the water jetter at the bottom of the piling and turn on the pump. The force of the water will displace the sand and silt, creating a hole for the piling. Guide the piling further down into the hole until you reach the desired depth. If needed, move the tip of the hose from side to side to ensure even installation. You can attach a PVC pipe with a 1-inch diameter to the end of the hose to increase water pressure if the sand is not easily removed.

Step 6: Stabilising the Piling

Once the piling has reached the desired depth, use the water jetter to push some dirt back into place around it to stabilise it further. This will provide additional support and ensure your piling remains secure.

Step 7: Repeating the Process

Repeat the above steps for the remaining pilings. Ensure that all pilings are installed at the same depth and are securely stabilised.

Additional Tips:

• Consider attaching a metal brace to each piling 4-6 feet above the bottom to prevent it from sinking further into the lakebed.
• Protect your pilings with piling caps, sleeves, or wraps to extend their lifespan by shielding them from sun damage, water damage, and marine life.

Choosing the right piling material

Natural Marine Timbers

Natural wood is a classic choice for docks, but not all wood types are suitable. Since pilings are constantly submerged in water, they need to be either pressure-treated or made of naturally water-resistant hardwood.

Treated Softwood

Treated softwood is a popular option due to its affordability and customizability. While it is vulnerable to decay and marine pests, it can be treated to resist these issues. Common species used include pine, cedar, redwood, and cypress.

Hardwood

Hardwoods, such as Greenheart, redwood, fir, and cedar, are naturally tough against water and rot. They don't require pressure treatment and are more resistant to decay and marine borers. However, they may be too hard for standard DIY tools, requiring pre-cutting and pre-drilling at the lumber yard.

Synthetic Materials

Synthetic materials, such as fiberglass, concrete, and steel, tend to require less maintenance than natural wood. They are often more expensive upfront and have specialized installation needs, making them more suitable for commercial applications.

Fiberglass

Fiberglass composite materials are a modern innovation for dock pilings. They are engineered to never rot, rust, or crumble, making them ideal for low-maintenance docks. Fiberglass pilings are straight and uniform, eliminating some of the challenges associated with natural wood.

Concrete

Concrete pilings are resistant to decay and can be reinforced with steel to improve their strength. They are safe for use in both freshwater and saltwater environments. However, concrete may not be the best choice for residential docks due to its appearance and installation challenges.

Steel

Steel pilings are strong and durable, making them suitable for commercial and industrial applications. They are coated with a protective layer to prevent corrosion and are resistant to insects, marine borers, and decay. Steel pilings can last up to 50 years with proper installation and maintenance.

When choosing the right piling material, consider factors such as water type (freshwater, brackish, or saltwater), weather conditions, freezing temperatures, boat traffic, and whether the dock is for a private residence or a commercial marina. Each material has its own advantages and disadvantages, so selecting the most suitable option depends on the specific requirements of your project.

Driving pilings into the lakebed

Choosing the Right Pilings

First, select the appropriate pilings for your project. Pressure-treated wood pilings are a popular choice due to their cost-effectiveness and resistance to harsh outdoor conditions. Alternatively, you can opt for plastic-coated wood or heavy-duty aluminium pilings. Choose pilings with a diameter of 6-8 inches if your dock weighs less than 10,000 pounds, or go for 10-12-inch pilings for heavier structures. Ensure you have enough pilings to place them about every 10 feet along the dock on both sides for adequate support.

Preparing the Pilings

Before you begin installation, chemically treat your pilings to prevent water damage and extend their lifespan. Cut the pilings to the appropriate height, taking into account the desired clearance above the water level, which should account for tides, flooding, or heavy rainfall. The pilings should be tall enough to hold the dock 3-4 inches above the highest expected water level.

Setting Up the Work Area

Recruit a few strong individuals to help you with the installation process. You'll need at least two people to hold and manoeuvre the pilings. If assistance is not available, consider using a tripod made of sturdy wooden pieces and a pulley system to hold the pilings in place. Set up your water pump and ensure the suction hose is in clean water, undisturbed by the jetting process. The discharge hose should be long enough to reach the bottom of the hole at the furthest pile.

Installing the Pilings

Stand the first piling in the desired spot and push it a few inches into the lakebed for initial stability. If the lakebed is hard or compacted, use the water jetter to create a starter hole. Mark your jetting pipe and pile with index marks to ensure they remain at the correct level. Attach an elbow at a 90-degree angle to the end of the jetting pipe to direct the water underneath the piling.

Turn on the pump and jet the water below the pile to displace the soil. As the soil becomes displaced, force the pile down into the hole. Work swiftly to drive the pile down before the soil resettles. Ensure you work the jetting pipe around the pile to keep it centred in the desired location. Once the pile is in place, use a rope or bungee cord to strap it to the dock, and check its alignment with a spirit level.

Finalising the Installation

Backfill the hole by jetting soil around the pile to stabilise it further. Repeat this process for each remaining piling. For pilings deeper than 6 feet, you may need to attach concrete to the top to overcome buoyancy and force them further down. Always wear protective gear during the installation process to prevent injuries.

Frequently asked questions