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Thomas Kasper Posted: May 22, 2007 08:46 AM	Floating Docks Hi Mason, What are some recomendations for building floating docks? Will the foam hold up and not absorb water? I understand 2lb foam will foat about 60lbs per cubic ft. I plan on building dock sections that measure 3'x12' and foam with 2lb foam at 6in thick. Each section will have 18 cubic ft of foam and according to the caculations each section will hold 1,080 lbs. Each section will have posts on the corners, driven into the lake botton, designed to allow the section to rise and lower. Sound good or sound bad?
mason Posted: May 23, 2007 08:11 AM	You would want to add a safety factor of around 50% to your calculations. You lose around 25% from the foam packing in and making a higher density product. Also, consider that the foam can absorb some water depending on how deep the dock is sitting. If the foam is 4-6 feet under water, there is enough hydrostatic pressure to breakdown the exterior cells of the foam and allow water to go in an inch or so. To prevent this, many folks fill tubes or drums with foam and strap those to the bottom of the dock. Hope this helps.
Gerry Wagoner Posted: May 23, 2007 09:12 AM	We like to use plastic drums (Iso from NAP for instance) and fill them slowly. Use a generous amount of silicone on the bung and you have a flotation vessel that is permanent. oG
Thomas Kasper Posted: May 24, 2007 08:45 AM	Thanks Guys, I forgot to say that the water is very shallow. It is only 18in deep at around 50' out. It is swampy shoreline but it gets nice once you get out past the weed line. I like the idea of drums filled with foam and strapping them on, when you have enough room. "Spray Foamin"
Doug Commette Posted: May 24, 2007 05:39 PM	Try a nice coating of polyurea or bed liner type urethane. That will make it much more ding resistant as well. We also have some other info on the site at the link to the left.
Posted: May 25, 2007 06:11 AM	i would check with your state DNR.... there are strict requirements as to what they will let people put on most public waters... they probably will not allow metal drums,,,more than likely will not allow plastic drums that have been used for paints, solvents... they may require "engineering" as this is a load bearing device..protecting ourselves from ourselves...
mason Posted: May 26, 2007 08:00 AM	Foamdude, This is good advice for any issue discussed on this forum. Please check your local, state and federal codes and regulations before any construction project. The Army Corps of Engineers have specifications on floating docks that are widely circulated and used.

Author

Comments

Thomas Kasper

Posted: May 22, 2007 08:46 AM

Floating Docks

Hi Mason,
What are some recomendations for building floating docks? Will the foam hold up and not absorb water?

I understand 2lb foam will foat about 60lbs per cubic ft. I plan on building dock sections that measure 3'x12' and foam with 2lb foam at 6in thick. Each section will have 18 cubic ft of foam and according to the caculations each section will hold 1,080 lbs. Each section will have posts on the corners, driven into the lake botton, designed to allow the section to rise and lower.

Sound good or sound bad?

mason

Posted: May 23, 2007 08:11 AM

You would want to add a safety factor of around 50% to your calculations. You lose around 25% from the foam packing in and making a higher density product. Also, consider that the foam can absorb some water depending on how deep the dock is sitting. If the foam is 4-6 feet under water, there is enough hydrostatic pressure to breakdown the exterior cells of the foam and allow water to go in an inch or so. To prevent this, many folks fill tubes or drums with foam and strap those to the bottom of the dock.

Hope this helps.

Gerry Wagoner

Posted: May 23, 2007 09:12 AM

We like to use plastic drums (Iso from NAP for instance) and fill them slowly. Use a generous amount of silicone on the bung and you have a flotation vessel that is permanent.

oG

Thomas Kasper

Posted: May 24, 2007 08:45 AM

Thanks Guys, I forgot to say that the water is very shallow. It is only 18in deep at around 50' out. It is swampy shoreline but it gets nice once you get out past the weed line. I like the idea of drums filled with foam and strapping them on, when you have enough room.

"Spray Foamin"

Doug Commette

Posted: May 24, 2007 05:39 PM

Try a nice coating of polyurea or bed liner type urethane. That will make it much more ding resistant as well.

We also have some other info on the site at the link to the left.

Posted: May 25, 2007 06:11 AM

i would check with your state DNR....
there are strict requirements as to what they will let people put on most public waters...

they probably will not allow metal drums,,,more than likely will not allow plastic drums that have been used for paints, solvents...

they may require "engineering" as this is a load bearing device..protecting ourselves from ourselves...

mason

Posted: May 26, 2007 08:00 AM

Foamdude,

This is good advice for any issue discussed on this forum. Please check your local, state and federal codes and regulations before any construction project. The Army Corps of Engineers have specifications on floating docks that are widely circulated and used.

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