4 Things to Consider When Choosing a Dock Float

4 Things to Consider When Choosing a Dock Float

Whether you are a veteran dock builder on brand new to floating docks, choosing your dock floats is one of the most important parts of the process.

Evaluating your float provider is an essential part to making sure you get the best deal and continue to keep everyone who uses your dock safe. In this blog, we will be talking about the top 4 Things to Consider When Choosing a Dock Float.


First is application. Where will these floats be installed? Who/what will be using the dock? Are there any special requirements that the dock must meet? Answering these questions is crucial to understand what dock float you require. If you are expecting heavy or commercial use on the dock, we always recommend going with heavy-duty, air-filled dock floats that are meant to withstand more wear and tear.

If this is just a backyard, residential dock, you might be able to get smaller dock floats that cost less. Everything directly relies on the application. With that all being said, once you have figured out your application and what sort of needs your dock float needs to meet, you can focus on the next step.


One of the most overlooked aspects of building your own dock is buoyancy. Our sales team has become really great at explaining this concept to our customers, making sure they are well informed before making a purchasing decision.

Buoyancy ratings (in short) allow you to estimate how much weight a flotation device can handle. All of our dock floats have a buoyancy of 55 lbs. per cubic foot. Your application comes into play here and generally dictates how much freeboard you would like your dock to have.

For residential customers, 12-14" is the preferred freeboard height. There are many extra calculations to do that require you to take into account everything that is on the dock (including the dock itself). Our team will gladly work along side you with some simple math to begin, but for specifics (and specially if you have never built a dock or building a marina) we recommend hiring a contractor/engineer to help you out.

Rough math for residential docks goes as follows: Our most popular dock kit (a 10' x 20' model) uses 12 inch tall floats and is recommended a 6 inch tall side stringer, 6 dock floats are included for a total of ~7,140 lbs. of buoyancy.

You normally want around 12-14 inches of freeboard height, meaning you would want the deck to submerge around 4-6 inches. A roughly 30% submersion, which means you would want your dock to sit around 2,100 lbs.

This weight includes the floats themselves, lumber, decking, accessories and any variables that are commonly present (people, pets, lawn chairs, etc.). Keep this in mind when you are building your dock, as if you are consistently exceed thigs, you may need floats that offer more buoyancy.

At maximum, you would want your deck sitting around half submerged, or 9 inches of freeboard height. Meaning you would not want to exceed ~3,570 lbs. of weight at any given time.


Now that we have all the math out of the way, we can move on to the next item for evaluation: Durability. Depending on where your dock is situated, weather can very and conditions can become quite severe.

On a day-to-day basis, your dock float will experience: UV exposure, changing tide conditions, animal contact, bumps from boats, salt contact (if on ocean water), debris contact, and other forms of potential damage. This is where application comes back into consideration.

The conditions your float is expected to endure will directly correspond to which float you should use in your dock. Most dock float suppliers stock fairly tough dock floats, but it is always worth checking to make sure.

A couple of protections you want your dock float to have:

• UV deterioration protection - Black pigment and resin that contains UV ray inhibitors are essential for a long lasting float.
• Rotomolded Construction - This will eliminate weak points and have your float be one cohesive piece.
• Made from polyethylene resin - For rigidity & overall durability

Again, this is standard practice with dock floats. The more important choice you will have to make are choosing between Foam or Air-filled Dock Floats. To make this a little easier, we will always recommend our foam filled floats. They are much more durable and can handle higher pressures.

If you are starting a brand new dock. or new at replacing/repairing existing docks, we recommend foam filled as the general solution. it's not to say there is not a place for air filled floats, but when you are first starting, its the safe choice.

Quality & Price

The last part to consider is the floats quality and price. Generally, you are paying for the floats buoyancy and durability. While it may be tempting to buy the lowest price float available, you are compromising long term longevity, durability and ultimately, safety.

There are a variety of different styles of floats, but you can generally group them into three categories, sorted by price.

1. Hollow Dock Floats
2. Foam-Filled Dock Floats
3. Heavy Duty Air-Filled Dock Floats

For almost all our new users, our experts will recommend foam-filled dock floats. The biggest reason why is they are the safest option, at the best price.

There are very specific areas where hollow or heavy-duty floats can be used, but at that point we recommend contacting an expert for their advice and design.

For more experienced contractors, these calculations are second nature. For anyone newer to building docks, we have designed DIY Dock Kits to take some of the hassle of calculating exactly how much buoyancy you need.

These kits include all the floats you would need, galvanized steel hardware, and step by step instructions on how to build the dock kit. You can find the different size of dock kits we have available below:

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