You need a new floating dock or you want to add on to your existing one, but money is tight, so you are thinking of building your own. The cost of a finished dock includes the following:
• The cost to manufacture the dock parts.
• The cost to transport the dock parts to the final location.
• The cost to assemble the parts into a finished dock.
It is easy to see that building a floating dock yourself can save you the cost of paying someone to assemble the dock for you. This article will show you how you can also save money on both the parts and the shipping, if you choose the right dock floats.
Custom Dock Floats
Dock floats are what keep your dock afloat. There are many companies that sell floats specifically designed for docks. Some floats are made of polyethylene plastic and may or may not be foam filled. Other floats are made of plastic coated Styrofoam.
One common dock float sold with dock kits is 8 feet long, 4 feet wide, and one foot high. This float has a polyethylene shell and is foam filled. The main function of the foam filling to make the float stronger, otherwise the shape of the float would cause the plastic to collapse on itself. The foam will absorb water over time so if the plastic shell is punctured, the dock should be repaired immediately as there is no way to dry the foam out once it is wet. This particular float costs about $260 not including shipping, weighs 110 lbs, and displaces 1815 lbs of water. A 20 x 8 foot dock would typically use three of these floats for a total cost of $900, if we include only $40 shipping per float.
When it comes to shipping, floats like the one described above are fairly light, but they are also fairly large and take up a lot of room on a truck. So depending on where the floats are manufactured, shipping can add significantly to the final cost of the float (often much more than $40).
Standard 55 Gallon Plastic Drums
Standard 55 gallon polyethylene drums have been used as dock and houseboat floats for at least 20 years and have proven to be extremely reliable. 55 gallon plastic drums cost about $40-60 new and are used in huge quantities in the food industry. When used for food storage, the FDA typically does not allow the drums to be re-used. This is great for the dock builder because reconditioned drums in excellent condition are available in most communities for $5-20 and with little shipping expense.
Because of their round shape, 55 gallon drums are extremely strong and do not need to be foam filled. This makes them significantly lighter than foam filled floats. And if they are ever damaged, the water can be completely drained and the drum can be repaired “as good as new” without the concern the inside foam has become waterlogged.
A typical 55 gallon drum weighs about 22 lbs and displaces about 480lbs of water. A 20 x 8 foot dock would float on 12 of these drums. Even at $20 each, the total cost of flotation would only be $240 as opposed to $900 for custom dock floats we discussed earlier.
There is at least one company that has started manufacturing aluminum dock kits that are designed to use standard 55 gallon polyethylene drums for flotation. These kits completely enclose the drums in an aluminum truss structure and are designed to work with any common decking material. The truss structure is so strong that poly dock wheels or even a highway rated axle can be added to the finished dock to make it easy to move in and out of the water. In addition, these docks can be registered and insured as U.S. Coast Guard approved boats. In some areas this can be advantageous if dock permits are difficult to acquire.
We hope you have found this article informative, and if you decide to build your own dock, you have a better understanding of your options to float it!