Hey guys, I am building a new dock in existing water. I was wondering what your ideas were for placing posts in the water. I am only going to be dealing with 2-3 foot of water and I have a tractor with an auger to dig my holes. The ground is pretty hard clay after the one foot of muck and does also contain gravel. My question is , what is the best way to anchor in the posts? I thought of using quickcrete ,but I was unsure of how to do it when the holes will be in the water. I also thought about just adding gravel and tamping it down. I have done the gravel thing with 20ft telephone poles and it held them up. The very front posts are the only ones I have to worry about dealing with water as my pond level is down enough I can easily concrete the others in. It is going to be around 16 x 25 ft. Any advice would be appreciated. Thank you, John
No problem with concrete curing under water. It is much heavier than water, and will settle around the posts and compact itself. As long as the posts are secured and don't move during cure, the concrete will be as strong or stronger than air cured concrete.
For what you're doing pouring underwater will probably be fine but will be weaker than if poured above ground. Wet concrete can become overhydrated. If you've ever seen the surface of concrete chipping off, it is likely that the person finishing it sprinkled some water on top to speed the process. The upper 1/4" or so becomes weaker and therefore chips off easily.
Are you trying to pour a footer for underneath the post or simply around to post?
Fast setting mix would probably be better than regular mix.
I put a steel plate with a 2.5' pin on the bottom for my "footers". It serves the same purpose as setting the post on a concrete pad. If you're using wood posts, a pin could be welded to the top of a plate and a hole drilled in the bottom of the post then the post could be slid over it.
Yet another option is to drive a tube into the clay then pump the water and muck out and then place your concrete, again fast setting would probably be a good idea.
I am just using it to pour around the post to hold it in place. Did anyone have any thoughts on using gravel and tamping it in? Thanks guys
If it's all contained in a hole, you don't have to tamp pea gravel.
get a concrete form from home depot that will slip over the post, pour it full of concrete. they come in diff. sizes. 1 should do, saw it in half.
Hey JK...
Let's get outta this box, eh?
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What if....
You set the pier on permanent concrete footers in the shallows that are accessible by equipment. Then, build a hinged section that attaches to the end of the last permanent section. Attach the other end of this hinged dock section (with another set of hinges) to a floating dock. It will always be at the perfect height. The drawback will be if/when you get a hard freeze. I don't know how much abuse the various floatation units will take, let alone the shear of moving ice floes.
Check out the muck pad and auger foot on this page
http://secure.tommydocks.com/index.cfm/choice/quarter_accessories/page/introThe ones I made for my dock were a sort of hybrid between the two.
Ok, I am either going to be using a 6x8 post or telephone poles because I have them already. Those all sound like great ideas and I will let you know what I do when the time comes ( this week hopefully) anyways I have another question for you guys. I was wondering if I could use 1x6 or 1x8 oak lumber on the deck. From what I know oak is pretty strong and is already rot resistant I think ? The reason I ask is I can get about 100 of these for 150.00 dollars. I am looking to go cheap ,but still have something strong that will last. I am looking at a 16x20 to 25 foot dock. If I can use these how many inches apart should my joists be underneath which will be at least 2x6 if not 2x8. Please help soon because those materials may be gone soon. Thank you again, John
Oh by the way the boards are 8 foot in length. Thanks
I think 16" o/c would be fine for oak planks. 16" o/c for treated pine 1-1/4" works and oak is a lot stronger. I've never seen it done but I'd bet they'd last quite a while considering how long oak barn siding lasts. If they were sealed regularly I'd bet oak would outlast unsealed treated. At that price I'd use the oak.
I must admit that I have never considered oak for an exterior application. It just never came up as a consideration....maybe cuz of it's normal expense over other options. This is interesting. Does anybody have personal experience with oak in an exterior application like decking?
I would make the joist's 8 foot long and then they would tie into a 16 footer going the opposite direction across the center. I could stagger the joists on either side of the 16 footer if you thought this would make it stronger.
This is from brettski in a PM
2 x 6 joist span of 96" is fine. The 16 footer is going to be bearing alot of weight. I would seriously consider a double 2 x 10 (or even a double 2 x 12 ???) beam to span the 16'. Think about the header over a 16' garage door; usually a double 2 x 12.
Brettski
What did you mean by pallet stock?
In 1974 I built a 18' x 36' deck with untreated, freshly cut red and white oak. Bought it directly from the saw mill.
The deck is still standing today.
HOWEVER, fresh cut oak shrinks terribly. I placed the 2x8 planks tightly against each other and I still had 1/4 inch gaps. Also, any piece that was not securely nailed or screwed to something twisted and bowed terribly. We put a 2 x 8 top rail on the top and where we made a 45 degree cut in each plank to form a corner the shrinkage between the two pieces was so great that we had to take off the entire rail cap and replace it with western cedar.
It also gets harder and harder to work with each day, especially if the weather is hot and dry. This is because the moisture leaves it rapidly.
On day one nails were easy to drive, on day 17, when we finished we had to drill holes in order to drive the nails.
You may not be talking about green lumber, but if you are beware.
Bing
No, it is not green lumber. Thank you
I have used white oak for cattle catch pens and for flooring on equipment trailers. It is preferable in these uses because it takes a pounding and distributes weight better than pine boards. Seems like it lasts @ 10 yrs or so on catch pens untreated. It is VERY hard to nail and sometimes subject to split. Hard, high quality screws would be the way to go. Don't skimp on the wood treatment afterward. I have had good luck with oil based. Your spacing should be the same though as if you were using pine boards.
So, I assume then that the whole frame should be at least 2x10 with a double in the center. I could then use 2x6 joists to screw the decking to correct?
Honeyhole- Bing
Thank you for your replies. I think you guy's have made me decide to do this with the oak. I still haven't been able to get a hold of the guy ,but when I do I will let you guy's no if I get it and what he says about the wood. Brettski said something about the fact that it might be pallet stock. I have no idea what that is. Thanks guys
Pallet stock is the bottom of the barrel quality oak. It's what they use to build skids.
Ok , Thanks
I still have no answer on his phone. Will let you know what kind of wood he says it is.
White oak would be fine. I am probably going to be building mine out of the same stuff along the lines of Brettski's floating dock idea, I have a small sawmill and lots of oaks. Red oak has open pores and may not weather as well, water can get into it easier. Oak does lift a lot more splinters than treated pine, so it may not be very good if you like to take your shoes off. Any green wood will shrink so plan for your gaps, they are only going to get bigger.
Ok guys, I finally got a hold of the guy with the oak and he stated it was rough cut he thinks. He said he gets it from an auction house and that the wood is cut straight and the right lengths ,but would need sanding or something to smooth the boards for walking on barefoot. Is all oak rough like this or is this probably pallet wood?
Oh yeah, is anyone familiar with galvenized grain bin flooring.There is a guy selling it for 5.00 for 12 to 20 foot sections. He advertised that it was good for trailer and dock flooring. I just can't picture what it looks like. Thanks
40 years ago, it was sheet steel thin enough to cut with tin snips that was galvanized on both sides. IIRC the strips could be joined together with crimped seams, but I've never installed any, just removed some when moving and restoring an old corn crib. Nowadays ???
JohnK.. I just built a pavillion out of white oak & would offer this.. I believe you will have to pre-drill all your holes before being able to use deck screws. Not a big deal, but something to consider when working with oak..du
Regarding the oak, you need to put an eyeball on the stock....or get a trusted opinion. First of all, verify the dimensions...particularly the thickness. If it is exactly 1" thick and rough sawn, you will be OK for deck boards that are supported by 16" O.C. Next test: if it is not split and cracked, knots are tight, and the boards are flat and straight, take it. (At this point, I must remind you that I have no experience with the weatherability of of oak in exterior applications. Based on the approval and input from others that have, I assume this part to be a given)
Do you have power surface planer (or a pal with one?) One very lite pass on each surface will knock down the rough texture and not remove too much stock. You will not remove all the saw blade marks, but who cares?
david u...a question to you about these 1" thick boards.
If they are cupped a little, will they crack when he puts the screws to them and forces them flat?....or, are they pretty forgiving?
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John...a note about cupping
If david u thinks you are going to be OK with a little cupping, you might have to re-think the surface planing procedure. As you can imagine, surface planing cupped surfaces is a waste unless you remove enough stock on both surfaces to get a consistently flat board....usually leaving a considerably thinner board.
I used oak boards for my decking 20yrs ago. Replaced it last year mostly due to the portion of the deck on the north side of the house. I used green boards & butted them with no gap. Worked fine except for the north side, there they never dried enough to leave a gap & rotted.
My advise would be to use 5/4 or thicker boards & make sure they will be gapped btw boards.
Brettski is right on pre drilling holes. That is a must. IME oak doesn't cup as bad as treated pine, at least it wasn't a problem with my deck which was apx 800 sq ft. Also as they weather the roughness softens & isn't much of an issue even barefooted.
Ric
Do you think that 1" oak stock attached to 16" o.c. will be too weak for suitable support? I would think that 1" thick oak is easily equivalent in strength to 5/4 southern pine. John's deal is 1" thick boards; I would hate to wave him off of a good deal if it will work.
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(edit; thanks for the kudos on pre-drilling, but that credit goes to david u and Bing)
I don't think 1" will be weak & IF you can judge each board for clearness (no knots or sapwood) they will prob. last fine. IME 5/4 or thicker boards would simply last longer because they would be more forgiving if there is a defect.
I used 3/4 kiln dried oak boards on my covered front porch & they are plenty strong enough.
... sorry, I should have read the whole thread closer.
Hello again, there is a picture of these boards on craigslist kansas city,mo. I do see knots in the pictures ,but they appear to be decent boards. Thanks guys
I also found an auction going on this weekend with treated 2x8's 2x10's and 2x12's. I haven't received an answer as to how many yhet ,but I may hold out until this auction is over. It is just so hard to wait when I get my mind set on doing something. I really want a large dock for my family to hang out on. My pond is 2 acres and in my front yard. I can just for see a small enclosed building or something attached to the dock to hang out in when the weather is bad and do who knows what in it. I was talking about cleaning fish and storing poles in it ( ok maybe I wasn't) ,but there will be room for that too. Anyways wish me luck on getting some good wood to build this thing. Thanks for all the help ,John
Hello, I found a guy that says he has 39 - 2x8 between 6 and 12 ft most over 10ft, 23 - 2x6 over 8ft and 8 - 4x4 post all treated for 200.00$. I am assuming this is probably a good deal. What do you guys think. It would be a great start to my lumber pile for this dock. The way I figured it I would be using 2x6 or 2x8's at 8 foot lengths for the deck. The guy from the auction also called today and stated there was at least 50 boards in the pile I talked about above. I think between the two I could have this thing built at low cost with a bunch left over. Thanks
Pressure treated lumber has always been my choice for exterior framing; period. It also winds up being my choice for decking for 2 reasons: lasts (virtually) forever...and...is the most affordable option.
Some notes on PT lumber.
I don't know the specific percentages of vendor compliancy or specifically when the change(s) occurred, but current PT from home centers is arsenic free. The old PT (maybe 8 - 10 years ago...?) was not. We have had some discussions within this forum regarding the potential of toxicity within a pond, particularly for the old stuff. As I recall, we wound up with no certifiable scientific evidence to point to yea or nay. Also, if it is the old stuff, you will definitely need to wear a face mask during cutting to eliminate the potential of breathing the dust particulate. Personally, I have built many decks in my younger years with "the old stuff" and never wore face protection. I'm still here typing...b'pamZ:Lfm:.........
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(kidding)
Also, the correct fasteners for the new PT is stainless. You can "get away" with galvanized, but it will react with the copper chromate (?) preservative and will eventually corrode.
I did read the post about the wood toxicity. I am not to worried about it. Also if the wood is old it will already have warped or shrank and I won't have to worry about much more of that. So I called the guy and got his answering machine of course and so the waiting game is on. Thanks again
JohnK, the SS deck screws I used were 3" #10 with square heads from McFeely's. I had a hard time finding a source & probably paid too much! Get plenty of bit drivers & use a screw gun if possible. This applies to the PT wood Brettski is talking about...du
I used 3" #10 SS screws with Torx heads, and they were too soft. I looked for some harder ones, but couldn't find any. They were so soft I could take my bare fingers and bend them double. I had to be careful with the torque setting, and kept some vice grips handy for when they occasinally twisted off.
So if you have a choice, find some stronger screws if you can.
Bobad and david u
Man...we could write a book. Don't ya just luv it when a stainless steel screw head decides to strip right when the head just starts to enter the wood? I have tried using screw extractors...that's a laugh.
I will say that I have never had product that was so soft that I could bend 'em in my bare hands, but I often wondered if the torx heads would be better than the #2 square. Guess not, eh Bobad? The one thing ol' cheap-azz Bski did discover...throw out the driver bit every now and then and replace it with a new one. That practice DOES make a diff.
Well, I purchased the load of treated wood I talked about earlier and I almost have enough. Unless I get some from somewhere else I will be headed to the auction this weekend to try and get some 2x10's and 2x12's for the frame. Thanks for the advice on the screws by the way.
JohnK, I'm probably a week late here but I've put in probably 50 or more grain bin floors. If it is plank style, I bet it would make a nice dock. The newer style bin floors are designed to make a smooth surface for easy sweeping. They are perforated to let air flow through or in the case of a dock, water to drain through. They are galvanized and snap together. You wouldn't want to cut many with tin snips, a partner saw would be ideal. The only problem I see with used flooring is that it may be bent up from disassembly and not fit back together well. The snap together very tightly with interlocking Js. Another problem is that if it came from a round bin, there won't be very many long ones and if laid end to end usually leaves a very sharp edge that has to be covered.
I think it's a great idea and will seriously consider it for the floating dock I am contemplating.
Here's a link for the type I used to install
http://www.brockmfg.com/uploads/pdf/BR_2051_0308GrainBinFloorsEM.pdf
Hello again, Well no luck at the auction. I did however just pick up 28 CCA 12 foot 2x6's and 32 CCA 8 foot 2x6's for 25.00. I also have lot's of other 2x6's and 2x8's I already collected. My plan as stated above is to build a 16x24 dock. I would like to make it 24 long on the shoreline and 16 feet out into the water. Because the water is so far down right now most of my post holes will be dug above the water line. I am trying to figure out how far apart to space my posts if I use 2x8's for the frame. I have plenty of post's so using a lot doesn't matter. Should I place 1 every four feet or can I get away with eight? Oh Ryan, thank you for the info on bin flooring. I will have to look into that and consider it for future projects. Thanks again guys
I am thinking every 8 foot which would mean 12 post's. I would have 8 foot squares basically in a grid that equaled 16 by 24. 4 across the front. 3 along the side going out into the water. Then 4 across the back and 3 down the other side with two in the middle. Something like this.
24
O O O O
16 O O O O
O O O O
Wow that didn't come out right. Oh well I am sure you guys get it.
O O O O
O O O O
O O O O
That's a little better I guess. Anyways will 8 foot apart be ok with 2x8's for the frame? I can possibly double them up or some of them anyways if need be.
John, are you attaching the joists directly to the posts or are you planning to bolt beams to the posts then set the joist frame over the beams? The latter is better because your joists won't have to span as far plus, you can cantilever the joist frame over the the beams about 1.5' without upsizing the joists. It makes it look like it's floating in air a bit.
Most big box home improvement stores have simple CAD programs that they can design your deck/dock for free. They'll usually print you some decent working drawings (usually a 3D too) and a material list. The parameters of these programs can be easily changed to accomodate different sizes of lumber.
I am planning to attach the frame to the posts and then the joist's to the frame,but that could change I guess. I am not sure what you mean by bolting BEAMS to the post. Are you talking about the outside frame when you say BEAMS?
There will be a 2x8 bolted to each post on all sides except for the outer post's of course, if that's what your asking.
This way the each joist will only span 8 feet and will be 16 inches apart. Does this sound good?
I am starting dock building today!!! I decided to make the concrete footings with the tubes in the water. My question is do you pre-mix the concrete with water before you pour it into the tube or do you pour it dry into the tube and let the pond water soak into it? I am assuming you premix so you get it all mixed well.
JK
I can't comment on your concrete pour. I have never done it in the water. I'm not sure I completely understand your plan. Maybe some of these other guys have done this before and can provide advice.
well we used the tractor auger to dig holes that were 3 foot deep and 6 inches under the water line. We then filled the holes with quickcrete that was dry and we let the pond water do it's magic.
I think quikcrete's fast setting can be poured in dry but from my experience, premixed concrete will force water out of the tube. Either way, the concrete will not be as strong as if it had been poured into dry forms and properly cured but I expect it will probably be good enough for what you're doing.
Thanks Ryan, I am in my third day of building and it's going along well although I have been having to dig my holes by hand. I have only 1 corner post left to set in the water and 1 8x8 section left to frame. It has definitely been a learning experience with a 20 minute ride 1 way to Home Depot each day. I am having fun and will post some pic's as soon as I can remember how. Thanks, John
Oh and that's a very nice picture of dock plans. That's what I did on my dock except there is one more section with two more post's 16 x 24. That's much nicer than my try at it.