Advice Needed On Deck Posts In Pond

smitty58

I've built decks for 30+ yrs but never built a dock. I have a deck to build that will cantilever out over a pond. The posts closest to the water will actually be in the water when the water level returns to normal. I typically sink my posts in the ground instead of on piers ,however for this one I'm thinking piers are a better idea. Anyone have experience with this? Is there any other options? Is sinking a 6x6 treated post in the ground knowing the water will be "around" the post acceptable? What are the negatives to doing it that way? What way would you do it?

Teetorbilt

We usually "jet" utility poles or drive pilings.

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smitty58

Not famaliar with the term "jet" ,but I was wondering if a telephone pole would work. Is that what you mean?

RobertCDF

If its dry right now I would just sonotube the pier 1-2' above the HIGHEST possible water level. Of course I would imagine the pier would need to be oversized over normal piers.

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Robert Shaw
Colorado Springs Custom Decks
Colorado Custom Decks
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Teetorbilt

"jet" is using water pressure to evacuate a hole around the piling. This only works in a loose substrate. The pole is erected in place and then high pressure water is applied around it to dig it in. In many places here it can be just hose pressure (60 PSI), some PVC tubing and time. I've seen guys jet 10' an hour with setup.

__________________
You can't solve you're problems with the same level of thinking that created the problems.

Albert Einstein

smitty58

Teetorbilt - thanks ,never heard that term before. I guess I'm thinking about doing it this way, auger a hole 12"-14" diam and 32" deep, pour concrete in the hole about half way then add the sonotube, bring the tube out of the ground 2-3 feet(above water level), install a j-bolt and bracket to hold a 6x6 post. Does that sound like a plan that will work to you?

Bone Saw

IF I'M understanding you correctly, you propose submerged augering? how deep? inches? feet? wont work... You will need several things, a pipe of the diameter and overall length you need for your pier to create a cofferdam, something to jet it in with, and something to evacuate it with. you will be able to jet and evacuate with a small trash pump, although you will have to somehow retro rig a 3/4" or 1" pipe to the discharge end for a jetting wand.

obxdeck

We jet 6x6 and 8x8 pilings here. It's mostly sand, so it may not apply to where you are. I have a small trash pump with a 2" outlet hose dropping down to a 1 1/2 peice of aluminium. I cut the end at an angle and flattened it out a bit. It makes the water come out under more pressure and at a 30 degree angle or so. I can take a 8x8x18 and drop it in the ground 8 ft in 3-4 minutes. getting it plumb is another story, but not too bad once you get the hang of it.
Good Luck