The Ultimate Guide to Dock Sway

 

Define Dock Sway

Dock sway is the side-to-side movement experienced when you walk on dock decking. The higher a dock sits, the more likely it will occur. It can also happen on deeper inland akes, even though the deck is only a foot above the water. Sway is the direct result of the length of the legs and the size of the leg material. 

We have published several articles to tell you about the continued rising waters on Green Bay and Lake Michigan.

https://wisconsinpws.com/rip-rap/  &
https://wisconsinpws.com/lake-michigan-water-levels/)

At the time of the most recent report, the water was 14″ higher than last year. Remember, last year was about 12″ higher than the previous year. 

Since the most recent update, it has continued to rise several inches more. The upward trend will continue through 2020.

How Much Higher Will the Docks be This Year?

 

It will be necessary to raise the docks to adjust for storms. It’s the only way to escape the waves’ energy. The high waves we experience in Door County means it is always prudent to raise the dock accordingly. 

What Causes Dock Sway?

The longer the legs are, the more likely you are to experience sway. Let’s look at two examples to explain this:

1. A flagpole tends to sway when subjected to strong winds. If you raise the pole 10′ higher without increasing the diameter of the flagpole, you will see much more sway. The higher the pole is, the larger the width of the pole must be.

1. If you step on a 6-foot step ladder, the first few rungs are pretty stable. You’re not high off the bottom. The higher you go, the more the ladder tends to sway.

 We do not advise this, but if you place your feet on the top rung of the ladder, you need to start looking for a safe place to land. 

How Can You Minimize Sway?

There are several things that you can do:

1. Increase the width of the dock. It’s more stable when walking on a wider pier. But, that’s not practical when you already have a dock.

2. The addition of cross-braces on the lower parts of the legs will reduce the swaying motion. Cross braces are rigid pipe(s) attached in an “X” pattern to make the dock stable. Usually, the cross brace attaches near the end of the dock, where the longest legs are used. The end is the most susceptible point on a pier when looking at sway.

3. New this year is the 3-Season Pier. This new pier will also be set high, but the legs are stronger (larger diameter), and the dock is more stable as a result. Cross braces would still be a good idea if your experience sway.

4. Give serious consideration to not installing all the sections you have available. See this article – Shorter Dock on April 28th.

Why Go Through Any of These Expenses?

You could let the waves destroy the dock and get a new one using the insurance money. Wrong!! If you re thinking this way, check out this article along with this article. Insurance will rarely pay for your damaged dock.

What Does the 3-Season Pier Use?

On the 3-Season Pier, we use 2″ schedule 40, galvanized steel pipe, which has an outside diameter of 2 3/8″. 

Compare that with the legs used by some competitors, which are 1 ¼” pipe or even 1 ½” tubing. (Tubing is the lightest or thinnest of all the materials used. Tubing is used mainly on all-wood docks). Both of these have little strength, and docks should never use them.

One Last Suggestion

One final recommendation is to use “Flow-Through” decking (see this article on May 19th) This decking minimizes the effects of the waves on the dock. With 42% less deck surface, it allows much of the wave’s energy to pass harmlessly through the decking. 

In conclusion

Give serious consideration to not installing the full length of your dock to avoid sway this year.

Tell Your Friends & Family

Have friends or neighbors you believe should see this article? Email them this link  – and Thank you!

Also, visit Pier & Waterfront Solutions on Facebook.

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