I need to build a new dock on my family's 4 acre pond. My other family members insists the dock must be stationary, supported by piers, to allow safe access by wheelchair. Even if a floating dock could be stable enough, they still wouldn't feel comfortable with it. So, floating is out of the question.
I wasn't able to build this summer but I am thinking building it in winter might be easier. This is mid-michigan. The temps have been consistently around 20 and our pond is well frozen over. The ice is plenty thick enough to walk on and seems level enough to build directly off from. Is there any reason (besides being a bit cold for some) that winter isn't the best time to build a stationary dock??
I have been a professional designer and builder my whole life. I am very confident with the structural aspects of my construction plan; My plan is to build a stationary dock using 0.60 treated 6x6's set into the mucky/gravel bottom. The dock will be almost 30 ft long and will require 16 ft posts for the depth at the farthest distance. I figure I can simply layout the dock on the ice, drill holes and sledgehammer the posts down till they won't move. I realize crossbracing will be required so I plan to pre-install a single bolted 2x4 to each post before sinking it down then chainsaw a slot in the ice to pivot the braces across. Next, I can set the headers directly on the ice (which should be rather level, right? I can always check and shim) then bolt them to the posts. Finally I can drop on the joists and finish the framing/decking.....all while just standing on the ice!
It seems so obvious that I am surprised it's not common practice. In facts, it seems almost too obvious and that it gives me pause. I did a lot of web surfing and I did find one professional dock building company in Ontario who say they build docks on the ice all the time. But other than that I am not finding anything. I have personally built several houses and countless decks in winter but never a dock yet. Am I overlooking something specific to winter dock building?
Every step sounds pretty good in winter - except using a sledgehammer to drive 6x6s into a mucky/gravel bottom.
I do not know of any builder that would construct a house deck using support posts set in loose fill. I think those would be set in an oversize hole that is backfilled with cement, or attached to anchors on poured concrete post bases. I would definitely apply the same construction rules to a pond dock, minus the concerns about frost-heaving of the support posts.
Further, if you are only working above the ice surface, then your dock and posts will be subject to "racking" failure if you do not have any crossbeams set down low on your posts. If your bolted 2x4s are going to be sufficient to stop the racking, then I think you will have a very difficult time driving your posts. The connected post and crossbeam are going to resist downward movement of the post you are attempting to drive.
I am pretty sure that you are a much better builder than I am, but those would be my concerns about your dock design.
Dad and I installed 2 docks during the winter. We used galvanized 2" dia pipe for the verticals. He had scrounged some cross piece brackets that bolted to the vertical pipe and allowed a 2" pipe to be placed horizontally and we drilled a hole through the bracket/pipe and dropped a 16 penny nail in it to stop the horizontal pipe from walking out.
We first used a sledge hammer then got smarter and hooked up a water pump. Screwed a fitting on top of the pipe, connected up the pump and washed the sand/gravel out of the way from the pipe. We found out that we had to stop 2'-3' from finished height and pound it down the rest of the way or else it'd sink on it's own.
The pipes held up for way longer than expected, 40+ years.
Then just lay the joists on the horizontal pipes and start building the deck. You can put a joist that is 2" taller on the outside of the pier to overlap the horizontal pipe if you don't want to see it.
We also used the same system to install a permanent boat lift. We used 2" vertical pipe that was at least 12, if not 15 feet long. Washed it in, pounded the last few feet. Slipped larger pipe over that and used pipe fittings on that to make the horizontal connections. That is still in the water, and it was installed in the late 1970's.
Last edited by esshup; 01/17/2206:03 PM. Reason: added boat hoist info.
I also used the pipe vertical method for new docks on my pond. It worked good for me. Pipe will pound in easier compared to 6X6s. I years ago made a dock on the ice with 4X4s. The strong arm guy pounding them in for me hit them with a 20 lb sludge hammer hard enough to split the tops.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
Washing down and driving hollow steel pipe is a whole different ballgame - and it sounds like a huge improvement for his situation.
How did you tie the wood dock elements to your steel support structure?
The wood hasn't been tied to the steel pipe at all. It sits on top of the horizontal pieces. Been sitting there without moving forever. 4' wide dock, three 2x8 stringers running the length of the dock, cross bracing of more 2x8's between the stringers (or joists). Dock is "L" shaped, roughly 60 feet long. I can't remember, but I think the pipes were installed at either 8' or 10' intervals. Decking was 2x6's, and when that deteriorated, it was changed to extruded plastic, which we found out is EXTREMELY slippery when there is snow/ice and somewhat slippery with water on it. But it is only slippery in the direction that the boards are running, which is 90° to how you usually walk on the pier.
I thought I had attached a sketch of the dock I am planning but I do not see it under my original posting now. I will attempt to attach that sketch again.
As for washing down, I assume you mean water jetting? My standard design and construction practice is to start simple then get increasingly more complex as the need arises (K.I.S.S.) and to me it seems that pile driving should accomplish the task. If after driving the post to maximum penetration the posts still seem too wiggly, I have already purchased a semi-trash pump that I can modify for jetting use. However, you can imagine my hesitation to jet if the water depth is of great depth. That, combined with dealing with a pump and inevitably getting wet in the cold temperatures makes jetting seem a lot less appealing. As of now, it is my observation that driving down to firm gravel will be more than sufficient considering the cross sectional area of the posts I am using. But, I can see how pipe, with a much smaller cross section would require more extreme methods; As one commenter posted: "Pipe will pound in easier compared to 6x6s". I suppose then the question would be, what is the minimum penetration depth required?
I don't think you believe them that the 6x6 will be too hard to drive. Let me use numbers to help you understand ... If you look at the area of the pipe you are driving approximately 1.62 square inches of area compared to 36 sq in... That is 22.2 times more difficult to drive in.. If you drive the pipe with a post driver you apply around 100 lbs per hit, to drive the 6x6 post you will have to apply 2220 lbs per hit to drive it... I doubt you're that strong, so the 6x6 will sit on the mud and provide no support...
I really like the idea of building on the ice, I wish i would have done that... Instead I tried to do it from a boat and my posts ended up crooked. I just drover mine with a post driver rather than washing them and it worked okay except for not being vertical... I think if you combine the two ideas you can build a great structure and it will last a long time... I haven't had much luck with treated lumber lasting when submerged lately, unless you get the creosote treatment in ties... Another reason I'd go with the steel well casings at least they last 40 or more years... Good luck... Later J
We really didn't get wet jetting in the pipes once we figured out how to do it. We just had a well pump that we used for the underground sprinkler system, and adapted the outlet to garden hose thread. Ditto for the top of the pipe (we had a manual pipe threader too). At first we tried tape and rags, or just holding the hose in the pipe with rags and that didn't work.
We installed a 75' seawall there too. We used the interlocking "W" shaped steel, either 5/16 or 3/8" thick. We washed/jetted that down too, using a piece of 1/2" or 3/4" pipe on the end of a hose. We used 8' lengths of the seawall steel, going 4'-5' down into the lake bottom because it was holding back soil. We capped it with a piece of 4"x4"x1/4" steel angle. That was installed around 1980. Still holding strong.
Now they have rubber reduction collars that are held in place with hose clamps, that might work without having to thread the pipe.
I doubt that you will be able to get enough force on the 6x6's manually to get them far enough into the bottom of the pond. To prove that to yourself, try digging a hole at the edge of the pond in a few inches of water, then try to pound a 6x6 down into the soil.
We went by the rule of thumb to have at least 1/3 of the length of pipe that stuck up out of the bottom of the pond into the bottom of the lake, going up to at least 1/2 the length (or more) when installing in shallow water.
We also found out that by installing a martin house on a pole that was attached to one of the pipes that was holding up one corner of the boat hoist was a bad idea. In one year, due to either the birds landing/taking off or the wind blowing on the martin house, combined with the down pressure of the boat that post sunk 3" over the course of a year. Our "fix" was to support the horizontal part of the boat hoist (floor jack with a piece of wood on the ice), unscrew the large pipe we slipped over the pipe we had jetted into the bottom of the lake, set a 3" long piece of pipe on top of that pipe, and re-attach the slipped over piece of pipe to the horizontal part of the hoist. AND put the martin house on it's own pipe........
We also found out that by installing a martin house on a pole that was attached to one of the pipes that was holding up one corner of the boat hoist was a bad idea. In one year, due to either the birds landing/taking off or the wind blowing on the martin house, combined with the down pressure of the boat that post sunk 3" over the course of a year.
Just call Esshup Engineering Consultants for all of your pile driving needs!
No more heavy construction equipment required ever again.
Call us for a quote on Purple Martin houses. Our unique designs can drive 2" steel posts to a depth of 8' in unconsolidated material.
Also ask about our Bald Eagle nests if you need to drive posts up to 4" in size. The eagles will work for free if you allow them two fish/day from your pond!
Update on ice dock; Layout and post setting went mostly as planned. I ended up moving the dock location at the last minute and found the water depth to be quite a bit shallower than the previous location. Layout was super easy. I drilled holes to set stakes. Using upside down marking paint on the ice worked excellent. Even better than marking on grass or dirt. String lines were ran and everything was squared up. I marked out hole locations and angered 10" holes for the 6x6 posts. I pointed each post to aid in driving them down. The points proved helpful in stabbing the posts in the proper locations but hand driving them from a ladder was quite tedious and I had to give up before getting any to acceptable depth. I locked everything together until I could come up with a new plan for sinking them. Ice conditions haven't been the best. We've been getting these huge temperature swings from well below freezing to nearly 50 in the sun. We are now past peak ice so I am going to be hustling to get post down and at the very least get headers attached. Being we had warm weather, I refocused efforts on getting our excavator running. I think it should be super easy to drive down the posts just by pushing them down with the excavator bucket. Also, if my ice thaws before building the platforms, I think I will just build on shore then swing them in place using the excavator too. Should be fun!