DIY floating dock: how to build the frame when building a dock

You need a new floating dock or want to add to your existing one, but money is tight, so you’re thinking of building your own. The cost of a finished dock includes the following:

• The cost of manufacturing the dock parts.
• The cost of transporting the dock parts to the final location.
• The cost of assembling the pieces into a finished dock.

It’s easy to see that building a floating dock yourself can save you the cost of paying someone to build the dock for you. This article will show you how you can save money on both parts and shipping by choosing the right framing materials.

Galvanised steel
There are many companies that manufacture galvanized steel frames. These are often sold as part of a kit that includes floats designed to work with the frames. Typically these frames come in sizes ranging from 2×8′ to 8’x10′. Typically, each frame is a single welded assembly that is hot-dip galvanized after being welded. The largest frames can weigh up to 300 pounds and depending on where the dock frames are manufactured, shipping can represent a large percentage of the final dock cost.

The significant weight of a steel framed dock not only adds to the cost of shipping, but an 8×20′ steel framed dock with suggested float will weigh 930lbs before decking. If your dock has to go out of the water every winter, this may not be the dock for you. Another downside to steel frame docks is that the metal is protected by a galvanized coating. No holes can be drilled in the frame or the protective coating will be broken and the metal will rust. This makes it more difficult to add or modify the dock.

Treated wood
Another option is to frame your dock with locally purchased pressure-treated lumber. With this option, a hardware kit is typically purchased that has galvanized steel brackets and fasteners. The hardware kit is small and relatively inexpensive to ship. While framing your dock with local treated lumber will save on shipping costs, wood-framed docks can be just as heavy as steel-framed docks. Also, unlike galvanized steel or aluminum, treated wood is not designed to be continuously submerged. This means that the dock must be built so that the wooden structure sits on the floats and rests completely on the water. Due to design constraints and the weight of the wood itself, wood-framed docks can be even more difficult to move in and out of the water than steel-framed docks.

Aluminum
Aluminum spring frames are significantly lighter than frames made from steel or wood. But some aluminum frames are welded units that can still cost a lot to ship because they take up a lot of space on the delivery truck. So, depending on where the dock frames are manufactured, shipping can still represent a large percentage of the final dock cost. There are companies that make aluminum spring frames that are completely bolt-on. These frames can be shipped in a set of small packages and can be shipped cost-effectively even from coast to coast. The final spring will also be significantly lighter. Most aluminum dock frames are designed to work with custom dock floats (usually sold by the dock frame manufacturer), however there is at least one manufacturer that has designed an aluminum frame dock kit that can work with 55 gallon polyethylene plastic drums. Combining the aluminum frame and plastic drums, the same 8×20′ steel-framed dock that weighed 930 pounds will only weigh 520 pounds. This is a significant difference that will make the dock much easier to get in and out of the water.

For many reasons, including dock weight and frame design, there has never been any floating dock manufacturer that put wheels on their docks. However, as of 2010, at least one manufacturer is now offering wheels with their aluminum sprung frame kits. They can be strong plastic wheels that allow the dock to be rolled up on the beach and stored there for the winter. Or an actual highway axle and tires can be added to convert the dock into a floating trailer and allow it to be towed directly from a standard launch ramp like a boat. This can be advantageous if your waterfront property is steep and does not have a beach on which the dock can be stored for the winter.

Another advantage of aluminum frame docks is that corrosion resistance is built into the aluminum and is not compromised if new holes are drilled for additions or modifications. Note: When bolting aluminum for use in saltwater or any water that has even a trace of salt, you’ll want to avoid stainless steel fasteners and use aluminum fasteners instead. Stainless steel and aluminum have an electrolysis effect in the presence of salt which causes the aluminum to corrode into a white flaky powder.

We hope you found this article informative, and if you decide to build your own dock, you better understand your options for framing it!