Accidentally building a 12' diameter pond

[combatwombat]

I'm far from a civil engineer, but I'm pretty sure that once geogrid is installed properly, whatever wall facing you are using is basically just decoration that is retaining the last few inches of soil. It is the geogrid that's doing all of the work. Like the freeway on and off ramps and see in every major city. They're like 30 foot tall walls made out of 6" thick concrete panels. It works because they're not actually the part of the system that is doing any of the soil retention.

 

[Brandyn]

An update: The backhoe knocked down most of the wall, and I'm slowly but steadily getting the blocks resituated on pallets to sell for most of what I paid for them. The learning experience was inherently valuable.

The plan: rebuild the wall with an appropriately dug footer, using natural native stone approximately 4'x5'x1.5', with Type S mortar and smaller native stone pieces between them. This way the wall and waterfall will blend fully together, as it was previously, except with mortar and larger rocks so the wall doesn't blow out this time.

 

[combatwombat]

Wowsers!

 

[addy1]

Welcome to the forum!

Got to love these learning experiences.

The learning experience was inherently valuable.

 

[brokensword]

An update: The backhoe knocked down most of the wall, and I'm slowly but steadily getting the blocks resituated on pallets to sell for most of what I paid for them. The learning experience was inherently valuable.

The plan: rebuild the wall with an appropriately dug footer, using natural native stone approximately 4'x5'x1.5', with Type S mortar and smaller native stone pieces between them. This way the wall and waterfall will blend fully together, as it was previously, except with mortar and larger rocks so the wall doesn't blow out this time.

footer; fine, but you're still going to need rebar and concrete filled blocks. If you're planning on putting a soil berm between the water and wall, that too will work. The main idea here is water pressure pushing sideways will topple most construction walls and especially block ones as block are built for compression, not sheer pressure. So to use blocks you need the rebar (to sink into the footing as well as tie the blocks together as your wall rises) every other hole. And use cement, not mortar as cement is waterproof and stronger than mortar, especially if you're going to have any portion touching water/wet soil/beneath the grade. And I'd cement plaster any of these surfaces in contact with the above.

 

[GBBUDD]

I searched the forum for new posts and whats new last night and this post never showed. and it's to bad because. the idea of building a two foot thick berm outside the retaining wall and coming up 3 or 4 courses on that retaining wall along with the soil i see on the inside of the pond i feel would have been fine. But it would have required pulling the layers apart as you did and simply mortaring the layers together making a brick wall and with the soil on the inside up as high as it shows in the picture again i think you would have been fine so long as your masonry skills were sufficient

 

[Phaewryn]

An update: The backhoe knocked down most of the wall, and I'm slowly but steadily getting the blocks resituated on pallets to sell for most of what I paid for them. The learning experience was inherently valuable.

The plan: rebuild the wall with an appropriately dug footer, using natural native stone approximately 4'x5'x1.5', with Type S mortar and smaller native stone pieces between them. This way the wall and waterfall will blend fully together, as it was previously, except with mortar and larger rocks so the wall doesn't blow out this time.

Native stone looks so much nicer than landscaping blocks. 4'x5'x1.5' stones? I am imagining something like this? But these are more like 4'x2'x1.5', so I am a little confused. 4'x5'x1.5' stones would be massive. Stones that size will give you wonderful support and you won't need any mortar or rebar after stacking those massive babies on top of one-another. Also, mortared or concrete walls require footings dug below the frost line else they risk buckling due to frost heaving (unless you live in an area that never freezes, you didn't fill in your profile so I don't know where you live). An unmortared wall is a little more forgiving in that is can flex a little where a mortared one just cracks, although with those size stones I doubt frost heaving will ever be a problem.

You never want to mortar a retaining wall that is holding back soil (or anything that needs to drain). If it's a pond wall and you're waterproofing the inside of it, that's another ballgame because you're addressing the water in another manner (with a liner), but you don't need mortar if you have these nice big stones. Or are you saying you have smaller rock and you plan to build the wall to be 1.5' wide and 4 or 5 feet tall? A 1.5' wide mortared rockwall of 4' height is probably going to need a lot of rebar. https://www.artofstonegardening.com/limestone-iron-wall shows what looks to be about a 1.5' wide and 4' high stone wall with rebar that isn't holding back anything: they say the rebar is necessary due to the thinness of this wall, and this wall is just a wall that is not retaining anything. I personally would never build this type of stonewall. I only build dry stonewalls. Maybe someone here has built something like you are and can be of more help. Please post a photo of your new stones when they arrive so we can see your new materials. I'm sure they will be much better than those landscaping blocks!

 

[GBBUDD]

Native stone looks so much nicer than landscaping blocks. 4'x5'x1.5' stones?

Agreed, but you have to remember the wood retaining wall is literaly 1/10th the price

 

[GBBUDD]

although with those size stones I doubt frost heaving will ever be a problem.

Even a retaining wall such as your showing is no match for frost but it will definately hold up better then will a cinderblock 8" wall alone but. with a gravel bed footing drain tile blanket behind the wall more gravel even a pipe or two and that wall mortared will last as long for a 1/3 the cost. getting boulders that uniform is not cheap by any means

 

[Phaewryn]

Agreed, but you have to remember the wood retaining wall is literaly 1/10th the price

Did this person ever have wood as an option? I must have missed that. You can do a lot with railroad ties.

 

[Phaewryn]

Even a retaining wall such as your showing is no match for frost

Right, maybe for the pond I depicted, but the OP says they have 4'x5'x1.5' stones. Those are massive. I can't imagine stacking 4'x5'x1.5' stone slabs on top of each other like sandwich bread, frost is much of an issue anymore.

 

[GBBUDD]

GUESS i missed that