Suggestions for 2 foot high wall on pond?

[JCschild]

now thats retaining wall blocks!..

 

[sissy]

sure are and took a lot to get this far .I had to rebuild part of the pond last year a new neighbors dog ripped my liner so when the say 45 mil liner can with stand anything ,they lie .Sucker was even heavier to take out as it had a suction grip on the ground and new one just as heavy .I have to do this all with only 1 person ,me .

 

[Waterbug]

funny guy

Seriously. If I could get inexpensive straw bales here I'd use them as a pond wall, especially here in Phoenix. Liner over the top, stucco on the front, one course high. Bet it'd last 5 years. On top of a concrete foundation could last 10 years or more. Good insulation too. I'm also thinking about Adobe. Could look cool and I would be digging it out of the pond.

There's really no limit to what can be used. As long as expectations aren't crazy. Just a question of what a person wants to do and have.

 

[sissy]

well here the field mice would love a straw house to live in all winter and have a nice nesting place for 100 's of babies and the snakes that eat the field mice would be 30 ft long and weigh 600 lbs or more . :razz: not sure I would like that

 

[Waterbug]

That sounds pretty cool.

 

[shanezam203]

SOLD on split faced concrete 8x8x16" blocks, thank you all. now the heavy lifting and hard work begins.

 

[Waterbug]

Pictures coming?

 

[shanezam203]

For the record, I agree with Sissy, I like the versatility of retaining wall blocks, they are kind of like building with Lego in that you can go back and fix or change things without beaking things apart, and you never have to mix any cement or mortar. Although I don't remember ever getting such a sore back playing with Lego???
Split face is the a common pattern for retaining wall blocks.

Nice pics, I found similar split faced blocks but in Grey. I like that you can go in and tweak yours if needed but I am using rebar and concrete/ mortar so it will be a little more permanent.

I am digging out the area this weekend, going down 4 feet and then will create the 2 foot wall about a foot back out of 3 rows of split faced blocks. Will update after we did this weekend weather permitting.

Thank you for getting me off my wood kick, this will look so much nicer and was exactly what I originally wanted to do.

 

[Mucky_Waters]

Nice pics, I found similar split faced blocks but in Grey. I like that you can go in and tweak yours if needed but I am using rebar and concrete/ mortar so it will be a little more permanent.

I am digging out the area this weekend, going down 4 feet and then will create the 2 foot wall about a foot back out of 3 rows of split faced blocks. Will update after we did this weekend weather permitting.

Thank you for getting me off my wood kick, this will look so much nicer and was exactly what I originally wanted to do.

I have seen people glue the retaining wall blocks together. In fact it is standard proccedure to glue the cap blocks on so they don't move.
It's a good idea to glue the caps because they can get kicked off, but personally I don't see the point of glueing the blocks themselves, if the ground settles or moves a little glue isn't going to stop it.
You can always tell retaining wall blocks from standard blocks because retaining wall blocks have a lip that hold the block on top from slipping off. that's what gives them their strength. Consequently retaining wall blocks are always stacked with a little step back with each successive row, so the wall angles back more and more the higher it gets, where building blocks stack straight up vertically.
For high retaining walls retaining wall blocks are stronger than building blocks, even though they don't have mortar to hold them together, because of the stepped, angled in the walls,
For short 2 ft walls it really doesn't make that much difference.

 

[shanezam203]

Yes I am doing a 2 foot wall using the blocks below, concrete blocks not retaining wall bricks.

 

[Craig58]

Just joined and saw your topic. In Chicago, your winters are going to be similar or worse than mine in Pennsylvania. I'm in the process of building my second pond that involves above ground stone work. My first is now 17 yrs old and no signs of problems. I've seen a lot of mention of block but not a ton of comment on foundations. I don't know about access to your yard but I highly recommend you have the foundation poured. The concrete cost is minimum and a good foundation makes the walls so much easier to build. I also didn't see what volume of a pond you are planning and what volume is above ground. The pond pressure is what is critical. With soil, only a limited depth of soil contributes to the pressure against a retaining wall. In a pond, all the water above ground contributes to the pressure. The pressure on the wall at the top is much less than the pressure right at ground level. A three foot high pond of 4x8 dimmensions only exerts 166 PSI at the one foot of depth. But at the three foot depth, it puts just under 500 PSI on the wall. Expand that same 3' high pond to 10x12 and it's 624 PSI at one foot and 1871 PSI at three foot. Since water is liquid, the entire volume above ground is exerting water on the wall as opposed to soil where only a certain amount of soil causes pressure on each block.

So yes, stone is the way to go. But back to your foundation. What I found sucessfull was to basically dig a trench in the ground for my wall's foundation. Dig it at least 15", preferrably 20" wide. The foundation should be at least 12-15" thick. And you want the top of the foundation to be about 3" below the finished grade. So overall you want it 15-18" below your final grade. I then dig a post hole down at 3.5 ft below the final grade at all corners and every four feet of wall. Once dug, I put in vertical rebar in the post holes and horizantal rebar in the trenches and tie to all together. I also used short vertical rebar about every three feet as well in the trenchs. These are set so as to be at the exact height you want the top of the foundation to be at. With three foot spacing you can lay your 4' level from one rebar to the next and get them very precise. You do a single pour of concrete, right to the very tops of those vertical rebar. That makes it much easier when pouring to know where to level off at. If done right, you can just make out the rebar tips in the concrete. By using the ground as a form, you save from having to build any forms. Now you can dig out the ground around the pour and grade it as needed.

If you did this pour correctly, you should have a very level surface to lay your block on. Taking care at this stage saves a ton of headaches later. With the rebar and 3+' post holes, you should never experience any frost heave on your pond walls. (the pond itself will help keep the ground from freezing as well so a frost heave isn't as likely around the pond. But a minor crack from a frost heave in the wall with all that water behind it can bring it down quickly.

I'm new here but when I figure out how to post pics here, I'll post some of mine while I'm building it. My new pond is 12.5' X 20' by 4' deep with about 20" above grade retained by a block wall. That's about 1800 PSI on my bottom course of block., 1100 PSI on the second course, and 325 PSI on the top course. (water level should be about halfway up the top course of block)

I hope this helps!

Craig

 

[addy1]

Nice post Craig, welcome to our group.

 

[shanezam203]

Craig, great info; just what I needed thank you. I planned on framing out a 10-12" base and lay mixed sand and gravel down. There I would need to level some low areas so that my 1st block is the same height all around the pond...

I plan on digging 4 feet down but that psi will be supported mostly by the ground level/ dirt walls correct? with the Concrete Blocks I only plan on going 3 rows high, so 2 feet. Is it correct only the water above ground level contributes to my pressure?
If so, again I am only going 3 blocks high and pouring concrete + rebar in centers + locking edges together with corner pieces.

Any more tips on this will help, thank you.

Shane

 

[JCschild]

Sigh::: building a house foundation for a pond.. i tend to over build everything myself (my house additions were built to FL hurricane codes etc etc, way over kill for KY) but this is an aweful lot of work and money.. (for a pond)

on the other hand if you want square not rounded corners and extremely symetrical (house looking) you dont have much choice but to go with the block.
if you intend to pour any of that block full of concrete (or mortar them together) then you also have no choice but to pour a footer.

if you pour a footer it would be best to pour it @ frost level.. have a feeling for you thats 36-40" (30" here)
never been fond of the "pier" footings craig mentioned.. that still leaves too much above frost level and its amazing what water turned to ice can do. rebar or not

 

[shanezam203]

JC, I plan to use the 4 foot dirt to build up my waterfall in the back & then fill in the back sides of each leg. Using a friends bob cat, so hope to get it dug in 1 to 2 days.

I want to go deep so the ground level 2 feet is able to freeze solid & the fish can survive at the bottom during cold Chicago winters.

I do want a square symmetrical look vs. rounded corners, that may be good for the blocks but bad for water flow I was thinking.