I need help with my new Dock design

[biglurr54]

I need some help building a new dock. This will be my second dock build. My first dock build(the one I’m replacing) was a few sections of scaffolding and some 2x6s for decking! It worked great for the 10 years we used it but its time for a nice dock that we can maintain and fit our boats at.

The lake is a small lake in upstate NY so I need to pull it out at the end of the year. The current scaffolding dock was too challenging to pull and set up each year so it has stayed in and then fixed each year in the spring. This was not fun. My lakefront is shallow and mucky but there is nice sand and gravel under the 10” of muck. My current dock is 48ft.

My plan for my new dock is to create two 20ft gangways out to a 16 x 24 ft floating dock at the end. My plan is to use a winch and pulley in a tree to lift the middle section of the gangway into the air, which will pull the floating deck in in the fall. The gangway will be on removable legs for stability purposes. I think I will attach pipe vertically to the end of the gangway and have the floating dock slide on the pipes. I will also chain the floating dock to anchors in a cross pattern.

I plan to make the gangway out of 3x either 2x6 or 2x8 beams and then make the decking removable. The floating dock at the end will be 16x24 and framed out of 2x8 with 2x6 joists 24” on center. I will stuff 16 barrels under the floating dock to float it.

Some questions I have:

1. Is there a better way to attach the floating dock to the stationary gangway?
2. Will I have issues with the floating dock breaking up the gangway from wind or waves?
3. Will 2x6 cut it or will I need 2x8s for the 20ft sections? What about the floating dock? @x6 knocks the price down but if the gangway will be springy it will be worth the money for the 2x8
4. Would it be better to float the gangway? I can increase the width to 4ft to make it stable but I would like everything very stable and not rock when your walking on it.

I have attached a quick drawing of the design.

 

[UP HOOKER]

That is an ambitious plan! On the large section if it is a floater it will not require as stiff of framing as the load will be spread around. One option for the walkways would be to use Aluminum planks that are usually used for scaffolding, they are available in some pretty large sizes (lighter and stiffer than framed) not to mention a lot easier.

 

[biglurr54]

That is an ambitious plan! On the large section if it is a floater it will not require as stiff of framing as the load will be spread around. One option for the walkways would be to use Aluminum planks that are usually used for scaffolding, they are available in some pretty large sizes (lighter and stiffer than framed) not to mention a lot easier.

I would assume the aluminum would be a lot more costly as well! Im trying to keep costs under 2k

 

[JimS123]

Look at the website. They have floaters and aluminum docks. They all pull out of the water easy. You might spend a few more bucks initially, but you'll never spend a dollar afterwards. They will last a lifetime. Build it yourself and end up spending more and not have a warranty to fall back on.

Been there, done that.

https://www.anchormarina.com/inventory/v1/current/EZ-Docks

 

[biglurr54]

Look at the website. They have floaters and aluminum docks. They all pull out of the water easy. You might spend a few more bucks initially, but you'll never spend a dollar afterwards. They will last a lifetime. Build it yourself and end up spending more and not have a warranty to fall back on.

Been there, done that.

https://www.anchormarina.com/inventory/v1/current/EZ-Docks

My price range is $2k. This is way out of that price range!

 

[alldodge]

How much does the water level change throughout the year?

Barrels are gong to leak someday, any plans to fill with foam?

Dock is floated with barrels but what floats gangway?

 

[biglurr54]

The gangway will be on 4x4 legs with angle braces. The gangway will be stationary. Just the large part at the end will float. The lake is controlled with a dam so the level doesnt very much unless there is a drought. I would say it stays within 6-8 inches.

I can get barrels to replace as needed. Maybe one day fill with foam or buy specific dock floats for the large part as the barrels leak.

 

[alldodge]

Suggest changing 4x4 to 6x6 and add 2 more of them on outer section

 

[biglurr54]

Suggest changing 4x4 to 6x6 and add 2 more of them on outer section

do you mean the larger outer section (16x24)? I would like to keep that part floating as it will be difficult to set up and take out in the winter if it is on legs. II figured the gangway would be fine with 4x4. I also considered metal pipe because I have leveling legs from all the scaffolding I have. I could do 4 pipes on each section of the gangway. I think i would need alot of legs, including some in the middle, on the 16x24 dock area. Could i get away with 8 galvanized legs on the end piece of the dock?

 

[JASinIL2006]

How protected is your piece of the shoreline from waves, wakes, etc.? I'd be concerned about the 24' floating section getting pounded broadside by waves, torquing the poles out of alignment, even with weights/chains.

 

[alldodge]

do you mean the larger outer section (16x24)? I would like to keep that part floating as it will be difficult to set up and take out in the winter if it is on legs. II figured the gangway would be fine with 4x4. I also considered metal pipe because I have leveling legs from all the scaffolding I have. I could do 4 pipes on each section of the gangway. I think i would need alot of legs, including some in the middle, on the 16x24 dock area. Could i get away with 8 galvanized legs on the end piece of the dock?

The second section of the gang way is my comment
The first section is held by concrete and then 4x4 at other end
The second section is supported by the first section and another set of 4x4 at other end

4x4 warp easy, 6x6 doesn't so much and there is enough to notch cut them to help support the load.

 

[alldodge]

Looking at your drawing some more I think your making it way to cheap. Your spanning that distance on 2 ft centers and no cross supports. The joist are going to start bowing and won't be long before it all has to be done over

 

[biglurr54]

Looking at your drawing some more I think your making it way to cheap. Your spanning that distance on 2 ft centers and no cross supports. The joist are going to start bowing and won't be long before it all has to be done over

Thats a good call. I could add cross braces between the joists every 48 inches to stabilize the barrels and prevent the joists from bowing./ deforming.

 

[biglurr54]

How protected is your piece of the shoreline from waves, wakes, etc.? I'd be concerned about the 24' floating section getting pounded broadside by waves, torquing the poles out of alignment, even with weights/chains.

Its a small lake and it is fairly protected. There's practically no boat traffic on the lake and the majority of the boats on the lake are smaller. I agree its a large platform that would also have two boats tied to it, including a pontoon which catches the wind, so stabilizing it is a concern. Im trying to avoid diagonal ropes to shore off the large dock. Thats how most people on the lake have their floating docks secured. I dont like the ropes because the would cross the beach area and are a pain with kayaking and the kids swimming.

How would you all get a 16x24 floating dock out 50 from shore staying in the $2k range?

 

[biglurr54]

Here's the current dock that it will replace. This is just scaffolding with 2x6s connecting it. Then a floating dock cabled to the scaffolding. This is 9-10 years old and never taken out for winter. It got moved around a bit this winter!