Setting an All-steel building in water

[Creamer]

I am planning on putting in a boat lift - permanent, i.e. not pulling it out in the winter - with an all-steel carport type structure over it. The structure is 12 x 31'. I am looking for suggestions on how to get this built out in the water.

This is to house my 24 ft pontoon so I have that to work with along with a small paddle boat and a canoe, some 55 gallon barrels, etc.

Building the structure in the water looks like a difficult task but if we build it on land how do we get in the water and leveled on its feet?

Suggestions?

 

[s219]

I know people who have used steel carports over their slips, and it works pretty well. Normally they build up scaffolding and walk-boards on their pilings, then work around the edges. Pre-fab as much as you can ahead of time on land.

 

[JoeL4330]

presumably the uprights are either driven piles or uprights set on an underwater foundation: (a) cribs filled with ballast stone; (b) precast concrete blocks craned in; or, concrete cast in place via evacuated sono-tubes (casings) and/or hydraulic cement and "rubble". As with pilings, the uprights only have to be, well, upright, and long enough to be cut off level once set. X-braced on three sides. Any (water quality) restrictions--can you cast cement in place? Winter worries about ice and freeze-thaw cyles? wave action? what kind of water depth are you dealing with? How did your neighbors do it?

or, maybe I misunderstood and you have the framing part licked and only want to put on the "roof" ...so, scaffolding, no? and use your frame uprights w. pump jacks?

 

[BHD]

First I have never done this,

but my first thoughts, would to be to drive or set a series of posts/piles on what would be each side, and then put across the posts some temporary cross, members, and then build the car port and (I would then probably put two pulleys on the far posts/piles and use them to help pull the car port on to the temporary cross members, and once in position, bolt the base of the carport, to the post/piles and then remove the cross braces,

 

[forgeblast]

I watched them put up my carport it went fast. I would have the posts in place and leveled. Then you would add the base plate (this would be connected to your posts then the uprights go in these are slip fitted and then have selftapping screws with washers that hold it in place. Next comes the roof ribs and supports same thing slip fit and screwed in. Finally the roof, what they did was put on one sheet then have a guy go up on the roof and screw it in as they pulled sheets off he kept screwing it in place. Took less then an hour for them to do everything.

 

[Brad_Blazer]

You could build a dock around 3 sides first.

 

[EddieWalker]

What is the carport going to rest on? If you are going to set posts into the ground for a dock, or support for the carport, why not use posts long enough to also support the roof? then all you have to do is build the roof.

Eddie

 

[sld]

Sounds like you need to build a small floating dock and then just bolt the carport to that. It would handle water level changes and let you pull your pontoon boat right under it. Use a hinged walk way too.

 

[PoorPlowboy]

For a boat LIFT you will need concrete pilings driven in and precast steel reinforced concrete beam runners along three sides attached to the top of the pilings. Then you can build your boathouse on top of the beams and have enough structure for your lift. A small crane or large winch truck will be required but the whole job shouldn't take much more than a day.

 

[bucktaker]

I just finished a floating boat dock 28x32 with a 10x26 boat slip. 15 4x6x20 encapsulated foam flotation,2x6 joists, 2x6 decking, triple 2x6,2x8,2x10 band boards. I built mine on the water side in three pieces pushed them in the water and then floated them and bolted them together. Pushed it around to where it belongs and set up the winches and anchors.

I am in the process of obtaining the material for a metal roof over the slip, i dont really want the carport type as I get lots of wave action and dont want the squeaking. I am searching for 8" galvanized Zee purlins
I will remove the deck board and attache the post to the triple band board with bolts then us the Zee purlins and metal panels for roofing.