Setting an All-steel building in water

[EddieWalker]

I'd be careful of building a floating dock that included a boat lift on it. You can't just consider the total weight of the building AND the boat, but also the change in it's center of balance having the boat up in the air. Just a few feet above the water is enough to make it very unstable. I wouldn't do it, but realize it is a doable project, it just requires a lot of additional support in both floats and surface area.

Eddie

 

[s219]

No way I'd put a boat lift on a floating dock unless it was for a very light boat and it was a very light lift system.

I have one of the smaller lifts you can buy, 5000# capacity, with aluminum frame so it's lighter than steel systems. Even then, with my 2400# boat up in the air plus some fuel (tank is 40 gals) it's a pretty good load swinging from the cables. My pier has telephone-pole-sized pilings driven down. Two pilings support the lift frame on each side. Sorry, this is not the best picture put you can sort of see the slip and lift on the right:



We left the end pilings at the slip high. Those will support the roof when we put it on (hopefully this spring). I'm going with a stick-built wood-frame roof system. I wanted to do one of these, from steel master buildings, but it did not pass architectural review in our county:



TO me, the benefit of the steel master arch system for a pier is ease of assembly. The corrugated roof sections bolt together in place. So you could slide them up over your horizontal side beams, and bolt together a section at a time. The sections will support the weight of a person from above, and then you'd want someone below to help tighten the bolts.

I looked into the steel carports (i.e., Carolina carports), but was concerned about the strength under storm/wind conditions here on the water. But for the price ($500-700) it's a good option if you can get away with it.

 

[bucktaker]

You all are missing the point the of a floating dock, the dock supports itself and any thing on the dock with floatation.. A boat lift is floating the boat and holding the weight, it is air operated to flood or lift the tanks to support the weight of the boat. It simply attaches to the floating dock to remain stationary within the slip.

HydroHoist 4400UL2 Boat Lift Series | Lake Lanier, Hartwell, Keowee, Boat Docks, Boat Lifts | Marine Specialties

My dock goes up and down 20 feet with lake level...Norris Lake La follette TN. A TVA flood control lake.

 

[MoKelly]

You all are missing the point the of a floating dock, the dock supports itself and any thing on the dock with floatation.. A boat lift is floating the boat and holding the weight, it is air operated to flood or lift the tanks to support the weight of the boat. It simply attaches to the floating dock to remain stationary within the slip.

HydroHoist 4400UL2 Boat Lift Series | Lake Lanier, Hartwell, Keowee, Boat Docks, Boat Lifts | Marine Specialties

My dock goes up and down 20 feet with lake level

Absolutely correct. At the Lake Of The Ozarks in mid-Missouri all people can have is floating docks. These docks support 40+ foot cruisers and cigar boats year round. There are thousands and thousands of these docks.

MoKelly

 

[Creamer]

Wow! Lots of good ideas. My pond does not have much wave action as it is a private pond (about 14 acres) plus the area I am putting it in is somewhat protected. My concerns were the ice but I was not thinking about driving pylons - I was thinking about metal feet that bolt to the structure and then tying it down with trailer house type anchors.

The pond has a solid clay bottom and the deepest point would be about 3.5'. The water height does not vary much through the year - about a foot total.

 

[EddieWalker]

You all are missing the point the of a floating dock, the dock supports itself and any thing on the dock with floatation.. A boat lift is floating the boat and holding the weight, it is air operated to flood or lift the tanks to support the weight of the boat. It simply attaches to the floating dock to remain stationary within the slip.

HydroHoist 4400UL2 Boat Lift Series | Lake Lanier, Hartwell, Keowee, Boat Docks, Boat Lifts | Marine Specialties

My dock goes up and down 20 feet with lake level...Norris Lake La follette TN. A TVA flood control lake.

I never seen or heard of a hydrohoist and can see where the stability of the dock or building wouldn't be as important since the boat is still floating on the water once lifted out of the water. My experience is with lifts that actually pick the boat out of the water with two straps that go under the boat, so it's hanging from the beams above the boat. This puts all the weight of the boat up in the air 8 to ten feet, which means additional floats to support this weight and more width to keep it stable. How much is the question?

In the picture, it shows huge dock structures, which would be very stable due to their massive size and the amount surface area they cover. You really cant compare that type of structure to a single boat lift structure in stability.

Eddie