dieselscout80
Elite Member
We have a block retaining wall (8"x8"x16" block) and we'd like to take the end of it and make a small circle to use as a planter. What is the smallest diameter circle that can be built with 8"x8"x16" block?
Block Wall Circle Question
- Thread starter dieselscout80
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I think the question you're asking is how few sides can a polygon made out of 8" blocks have so the exposed mortar joint is acceptably small, probably around 1/2" wide. And then you'll want to know what is the dimension across the flats of that polygon, which is approximately the diameter of a polygon that approximates a circle.
If that's what you want to know, without doing the geometry, my guess is it's on the order of 10' across the flats. If you could use 4" block instead, that size would be a good bit smaller. Or if you could make it out of those angled landscape blocks it could be a lot smaller.
If that's what you want to know, without doing the geometry, my guess is it's on the order of 10' across the flats. If you could use 4" block instead, that size would be a good bit smaller. Or if you could make it out of those angled landscape blocks it could be a lot smaller.
Sutol
Platinum Member
You could cut the blocks in half and at an angle to tighten the circle with tight joints
Craig Clayton
Platinum Member
Could you post a pic of the block retaining wall, as some members might have some different thoughts.
Craig Clayton
Craig Clayton
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dieselscout80
Elite Member
MikeD74T
Veteran Member
Ten 16" blocks will give an inside diameter of just over 48". Whether laying with mortar or dry stacking you'll have very large joints on the outside (i.e.4"), so if you cut 1" off each end of each block on the inside diameter you'd still have 2" joints on the outside with a slight reduction in diameter. You need blocks with ears (strechers) rather than square ended (jamb) blocks for this. You can go smaller understanding that the fewer blocks the less "round" it will be. MikeD74T
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dieselscout80
Elite Member
Thanks Mike.
I'll take a pic and hopefully that and a bit of hick english will make it clear. :laughing:
Basically I want to take the far end of that wall (left side of pic) and turn it counter clockwise and end up with a planter at that end. I am willing (kinda want to) shorten the wall some too length wise.
Here is a pic I found that kinda shows the end in question. The wall at its tallest is 6 blocks above the ground level and steps down to 3 high at the end in question.
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Damifino
Gold Member
I've seen these used on some jobs before, if you mix and match, I believe you could get close without the wide mortar joints. one is 22 deg other 45
Just a thought
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Egon
Epic Contributor
There are also half blocks that can be used.:
Check with the local concrete block supplies. They may be able to help you out.
Or consider using a catch basin section in a length that you like.
Check with the local concrete block supplies. They may be able to help you out.
Or consider using a catch basin section in a length that you like.
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dieselscout80
Elite Member
magicheater
Veteran Member
It looks to me that you have a curved wall to start with. Perhaps the answer lies within the wall. Purely an exercise in mathematics but you can just align the block you are using with the size of mortar joint you are comfortable with and then do the math.
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dieselscout80
Elite Member
Yes, but I want a tighter curve and in the opposite direction of the current curve.
Block won't resist pressure against it's concave side, so if you fill the planter with dirt the blocks are likely to crack and move out over time. You'll need to put some kind of wire along every course to keep it in place. On a straight wall it's called track and looks like a ladder made out of welding rod. You'll have to improvise on a curve like that. You could probably bend 3/8" rebar by hand and use that, although it's way heavier than you need. Maybe some 3/16" welding rod. Weld the ends together so it's a continuous hoop, or overlap a few sections.
MikeD74T
Veteran Member
The angle block are meant to be stacked to form a vertically straight corner. They willl work but will not be "round'. Half block are square ended & much more difficult to cut if it's desired to reduce joint size as well as there'll be less overlap of blocks but would be "rounder" than full block.
I'd take down 4 ' of the existing wall & go with a bigger radius. Filling the cells with grout/rebar will help with freezing/pushing concern but good drainage behind the wall is even better. The existing wall seems to have held up ok. My first post assumed 8" block but the wall looks to by 10" or 12"??? MikeD74t
I'd take down 4 ' of the existing wall & go with a bigger radius. Filling the cells with grout/rebar will help with freezing/pushing concern but good drainage behind the wall is even better. The existing wall seems to have held up ok. My first post assumed 8" block but the wall looks to by 10" or 12"??? MikeD74t
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dieselscout80
Elite Member
We measured them and yes they are bigger 12".
MikeD74T
Veteran Member
You can still tie into the wall with 8" block, they'll make a better turn. 8' diameter or so should make a good looking planter. I'm guessing you need about 1/3 -1/2 circle to die into higher ground? If I wasn't 1000 miles away I'd lay the block for you. MikeD74t
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dieselscout80
Elite Member
I just thought of another idea.
What if I got a piece of concrete culvert and used that to make the planter?
Is that what you meant by a catch basin Egon?
What if I got a piece of concrete culvert and used that to make the planter?
Is that what you meant by a catch basin Egon?
Much better idea
Egon
Epic Contributor
Yes, that is what was meant by a catch basin or manhole section. They might come in shorter lengths.
