DIY 4×8 Floating Dock section

My last 8×8 floating dock section was built from mostly salvage materials. I’m slowly adding sections until it reaches shore. Unfortunately, I can’t use the cylindrical foam floats as the base of walkways, as they will rotate/spin in the water. (Also, I have plans for the other 2 cylindrical foam sections….)

Two sections of floating dock on lake

So this 4×8′ section of floating dock uses two commercial roto-molded dock float sections (48x24x16″), which drove the price up to around $680 in materials. (But I have a decent number of composite deck boards and hardware left for the next (3×12′) section I plan on building.   [Yes, every section of my dock will have a different width, deal with it.]




8×8 floating dock section


I bought a 8×16 floating dock for $100 delivered. The main reason it was so cheap was that they had originally used Melamine covered particle board for the decking, with predictable results.

But the pressure treated 2×6’s and foam floats were in relatively good shape, so I bought 4 brand new 2×6’s to have nice new lumber on the outside, and built my own 8×8 floating dock.

I used 7 2×6’s total (4 new ones and the 3 interior ones salvaged from the original dock) to build the frame around the foam floats, wheeled it down to the lake, and then screwed in 19 composite deck boards.

And here is the finished product (before adding hardware to fix it in place with pipe floats, bumpers, solar lights, etc…)


The total cost was about a dollar per pound of dock. The composite deck boards were the heaviest and most expensive single item, although the hardware to hold the dock on pipes and attach it to other dock sections will also add significantly to the cost.

Item Price Weight
Old Dock parts w/ Delivery 50 100
4 (new) + 3 (used) 2×6 -ground contact PT 23.52 117
3x tubes of black calk 14.34 2
deck screws 3.5″ 8.05 1
19 composite Deck Boards 252.7 307
2 lb deck screws (1 5/8″) 16.08 2
2x TommyDocks floating dock pipe guide (with pipe & augers, not included in the weight) 111.9 4
4x Solar Pathway Lights 57.95 1
Totals (Cost / Weight) $534.32 534lb