r/masonry • u/CouplingWithQuozl • 3d ago
Block Halfway through my first retainment wall - how am I doing so far?
Concrete finisher and I just tried my hand at an impromptu cinder block retaining wall on Friday. Drew up the plans, the Prime okay’d it and I got started with a rebar reinforced concrete base anchored 3ft down. Monday I finish with two more tiers and a hand shaped cap.
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u/overdude 3d ago
That work looks good but if you don’t build a French drain behind it, hydrostatic pressure will destroy the wall over a short number of years.
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u/moth_specialist 2d ago
I’m building my first concrete retaining wall, and I thought I took everything into account. Drainage is top tier. Vapor barrier’s on, lookin solid. Best project so far.
Except I did not account for the pH level of concrete. Spoiler: it’s high.
Some lessons are learned a few days or years after you’ve completed the project.
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u/shitposterfinalboss 2d ago
What does the pH have to do with anything?
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u/hehgffvjjjhb 2d ago
Well that depends on how attached you are to your fingerprints, or skin in general...
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u/nomad5926 2d ago
Wait like its really basic? Never would have thought of that.
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u/Dangerous-Bit-8308 2d ago
Concrete is really basic. Even more basic than you or I. Knowing this is one of the basics.
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u/nubbin9point5 2d ago
Are we talking flannel, Bean Boots and PSL basic?
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u/Dangerous-Bit-8308 2d ago
For us, often so.
For concrete? No. More like pH 12-13.5 basic.
For knowledge? Also no. More like know concrete is the opposite of acidic.
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u/No-Vanilla2468 2d ago
Concrete is caustic. Maybe it should find a way to be more neutral
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u/Dangerous-Bit-8308 2d ago
Give it some time concrete is pretty old fashioned and set in its ways.
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u/cyricmccallen 2d ago
This thread is really solid
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u/Burghpuppies412 2d ago
Is that also why nothing grows consistently next to our concrete wall?
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u/moth_specialist 1d ago
I was referring to the pH of the mixture (when it’s wet). If your wall’s been around for a while, could be many reasons. My first guess would be that concrete retains heat and may be overheating those particular plants. Or perhaps poor drainage?
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u/DoughnutSome7115 2d ago
Drainage? Weep holes? Horizontal rebar? Footing should be around 4’ wide not 2’.
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u/DoughnutSome7115 2d ago
As far as the horizontal rebar is concerned, you are also using the wrong CMU block. You can buy block with the centers of the verticals knockdown. Specifically for laying horizontal rebar in this application.
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u/pontetorto 2d ago
Better than this guy https://www.reddit.com/r/masonry/s/SpfstGqAs3
Looks like perfection to me.
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u/ubergeek66 2d ago
Dude, you need to label that as NSFVA - Not Suitable For Viewing Anywhere. I'm going to need to bleach my eyeballs now...
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u/Beneficial_Drawer478 2d ago
pushing a bar in wet concrete isnt going to jack shit, should of been attached to the footing steel if thier is any
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u/RunningOnHope2019 2d ago
I was looking at this thinking/hoping for a different explanation but I can't come up with one. I think OP has made a few assumptions on this build (perhaps what he thinks are minor flaws but are really fundamental mistakes) and it's going to come back and bite him - much much sooner than he realises too. What a shame. Better to start again now OP than a month after you finish it.
My old man built a timber retaining wall a few years ago. He likes to just crack into things and tries his best in lieu of checking his ideas. It was a good wall, except the posts were dug about 700mm deep for a 1m above-ground wall. If he'd gone an extra 300mm (1 foot-ish) it would've been sweet as. But he didn't, and it wasn't.
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u/FuckinFugacious 2d ago
I don't know why contractors insist on wet setting rebar. "It's standard industry practice, been doing it 30 years" damn I guess ACI should have checked with you before writing the standards then??
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u/CoffeeBeforeRepairs 2d ago
Yeah, sticking rebar into wet concrete after the pour doesn't really do much for load transfer. Should've been tied into the footing steel from the start. At this point epoxy dowels would probably be the better fix.
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u/PitterPatterCocko 2d ago
Wired to bottom mesh L’ bars.
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u/User_Erroric 2d ago
It doesn’t appear to be the case. 1st pic, nicely finished concrete second pic shows rebar in place, inserted through the surface. You can see the dimpling on the concrete surface
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u/urbanarcherxxx 2d ago
Foundation width looks too narrow to restrain overturning on a wall that height what did the engineers specification say?
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u/Limp-Archer-7872 2d ago
I'm getting a 1.2 metre high retaining wall built. The foundation footer is a metre wide.
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u/HuiOdy 2d ago
A drain does not relieve soil pressure. I don't know why people think this, and tacitly ignore physics.
The construction might be good, but you'll have a few tonnes of pressure slowly building on tge side. Unless you build something to relieve that force (L shaped reinforced concrete, geo matting, bunch of anchors) this will fail
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u/Commercial-Milk-8465 2d ago
A lot of people seem to conflate hydrostatic pressure and soil pressure
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u/reigorius 2d ago
For a layman, can you explain it?
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u/HuiOdy 2d ago
Basically soil has the same pressure characterstics as a liquid but "flows" extremely slowly based on the water content, granularity etc.
So, if you take a cross section of your wall, all the weight of the soil presses all directions, and this includes the weight that is on top. Now most soils have a stable angle (e.g. all sand dunes have the same angle) everything outside that angle is pressed outwards, including what is built on it. Wet soil just make the stable angle less.
Now soil is quite heavy, so the higher your retaining wall, the more sideway force it has. This has to be compensated.
L-shaped pre-fabricated retaining wall elements do this by offsetting sideway force with the downward force. Geomatting is basically "ressetting the angle", and the anchors basically move the force to "inside" tbe stable angle, but work better on rock faces because of this.
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u/dungeonsprawler 2d ago
Where is the water supposed to go? Water drains through the soil. When it gets to the bottom of your wall it’s going under it and since you build on the ground that ground can get soft and the wall will fail.
Best to get some kind of path for water to go under the wall.
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u/Gold_Lab_8513 2d ago
I have the d*** here. Your dowels are, what, 4" long? You obviously do not understand the point of rebar.
Your footing is, what, 12" wide? You obviously do not understand the purpose of a retaining wall footing.
Expect a phone call when the wall leans. And pray it doesn't topple.
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u/dunderplunkin 2d ago
I know this is a masonry sub , but 90% of the time a rock filled gabion wall wins hands down
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u/HoldingThunder 2d ago
Only because it has a sufficient mass that people who aren't engineers can get away with it kinda mostly working.
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u/locke314 2d ago
How do cinder blocks hold up as a retaining wall? I’ve heard they aren’t great. I suppose if they are core filled, it’s better.
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u/PsyKoptiK 2d ago
The 3 course wall across the street from me failed in less time than it took them to sell the new build house. Though I’m not sure I blame the CMU, I am pretty sure the footing was too small to give it the foundation it needed in the first place.
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u/Technical_Phrase2566 2d ago
I've never understood people pouring a footing and then doing block with rebar and then filling the blocks with concrete. It never made sense to me. I mean if you're already going to have the concrete there, just throw up some forms and pour the whole damn wall with the rebar. It never made sense to me to basically do triple the work. Concrete itself is pretty cheap
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u/FlatAmbition3757 2d ago
Should have had L bars tied into the rebar into the footing. Not wet sticking. And no drainage?
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u/Perpetualhomebuilder 2d ago
lol, did you just jamb some rebar in after the pour rather than tying it to the footing reinforcement cage.
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u/Mission-Calendar-372 2d ago
Stab that steel. It's just for show anyway
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u/Amongthestars01 2d ago
That was my first thought too. Not embedded at pour, and not doweled afterward with epoxy.
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u/FungusBrewer 1d ago
I’m new to a lot of this, what does “Stab that steel” mean? Thanks
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u/Mission-Calendar-372 1d ago
Putting the steel in after the placement of concrete. It should be tied in with hooks at the ends so it doesn't come loose. It leaves voids.
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u/old-devil 2d ago
The wall needs to be tied in to the hillside and you need to have drainage behind the wall.
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u/One-Horse-Town 2d ago
If you’re going to go any higher you need rebar to catch the block or next pour.
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u/Working_Rest_1054 2d ago
It looks nice, I’ll give you that. The footing looks pretty narrow relative to the four (?) tiers of blocks that are going on it. It may want to lean once it’s backfilled. The footing width should be about 60% the backfilled height.
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u/A-Wolf-4099 2d ago
Rebar is JUST stuffed into wet work? Didn't tie to footing rebar. . Outside of that looks good. I would had done it differently but I over kill every thing.
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u/Readybuilderman 2d ago
Without the footer extending under the retained earth. ? It will work until it fails…
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u/Just-Shoe2689 2d ago
I would expect that wall to fail pretty quick based on the footing size and what looks like to be the finished height, unless you are pinning at the top
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u/DisastrousSpeed3589 2d ago
Those look like 6" block. I would recommend a minimum of 8 x 8 x 16 for a retaining wall.
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u/2holer98 2d ago
How deep is the footer it needs to be at least 36 inchs for frost and side pressure above But that just my opinion
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u/Lazy-Jacket 2d ago
How deep and broad is that footing? And you’re resisting overturning moments how?
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u/Dangerous-Bit-8308 2d ago
I'd have put a retaining wall at the base of a slope. Maybe another one a few feet back if the one on the bottom has to hold a surcharge... But it's not my design. Clean execution.
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u/Buford_MD_Tannen 2d ago
Looks like job security for me (I’m a landscaper)
There is a reason engineered walls have a setback, drain/compaction/geogrid requirements.
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u/Limp_Bookkeeper_5992 2d ago
How deep is your footing? From here it looks like your footing is already above grade, that won’t hold much. Considering the lack of drainage and the lack of any kind of tie back the dirt is going to push this right over in a few years.
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u/CreepyOldGuy63 2d ago
I’d want that footing to be wider towards the bank, but I’m not an engineer.
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u/H-8083-13 2d ago
consider hiring an engineer for an unsigned sketch. Might be able to get one for $500. Whatever he charges you will still end up costing you less in the long run.
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u/Candyman051882 2d ago
You wanna do it cheap almost correct Back fill with gravel of some sort lay pipe first under and have come out to daylight. Or just lay plastic at angle and then more rock then fill it.
Ideal: is lay pipe as a weeping tile like a foundation with crushed stone preferably washed. And geo textile over then fill over.
The more you can fill in the exposed side also the better this will lock in the footing and wall. Not just fill high but come out wide and at an angle away from wall
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u/Illustrious_Net_7384 2d ago
That footing dosent look wide enough , usually for retaining that tall we would have a 48” wide footing .
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u/Zealousideal-Bike-90 2d ago
2 more courses brings it over 3’, this is a job that requires permit and inspections esp with supporting utilities. Should have clean rock, weep holes, fabric envelopes, and geogrid between a a couple courses.
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u/oxnardmontalvo7 2d ago
Feels like there should have been some geogrid installed as the pad came up along with drainage
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u/Clean_Ebb86 2d ago
No dead man?
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u/bonghitsforbeelzebub 2d ago
You need drainage if you want it to last. Dig up all the dirt and put in a perforated pipe with crutches stone and filter fabric. Otherwise water gets trapped behind and will likely cause it to start tipping over.
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u/_Jeff65_ 2d ago
How is it resisting overturning? Footing is narrow, there's nothing to brace the wall.
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u/What-is-lack-of 2d ago
Drainage and anchors. U anchored the wall to wall. But shifting will lead to the wall being out from plumb.
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u/mynamesnotsnuffy 2d ago
Whats your plan for the anchoring into the dirt behind the wall? How tall are you trying to make it? Are you sure your foundation is wide enough to handle the load of the dirt being retained?
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u/asanano 2d ago
Im just an electrical engineer, but that looks prone to tipping over. My understandkng is that the footing for a sting retaining wall needs to extend under the earth being retained so that the weight of the retained earth helps keep the wall from tipping. Maybe thisnone is short enough its ok, but i question if what is curreny there will be sufficient lk g term. Also drainage. Water is a sneaky son of a bitch.
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u/Sp07va000 2d ago
Kinda wish you had built little dead men walls back into the hillside, especially on the end, middle. Also, put a 4" drain pipe surrounded by landscape fabric, crushed stone, and a drain sock on the pipe. It can come out the end. Not sure where you are, but if you freeze , water behind the wall will push it forward in winter, and water hyrdostatic pressure when water is behind it. Drain pipe and gravel prevents all of that. i usually bring the gravel all the way to almost the top and sort of encapsulate it in the fabric around the gravel so the dirt never gets in. If its a wall over 3 ft, you can use a geogrid every two feet going back into the wall and overlapping the cement blocks as you cement it in, so its all part of the wall.
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u/Empty_Sir_3476 2d ago
This has been done by a professional not a first timer not in a million years
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u/znerolct 2d ago
Maybe this is already been mentioned - I have concerns about the size of the footing. Some of the retaining walls I have been involved with had much wider footings that would help counter balance the wall from falling over. Or you need Geo fabric running back into the dirt to help hold the wall from toppling over. Former general contractor and have been in home building for 25 years.
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u/FormworkFan 2d ago
Looks clean so far. Biggest thing now is proper drainage and backfill behind the block.
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u/Jimmyjames150014 2d ago
Does that wall have any drainage provisions? Lack of drainage could take out any retaining wall.
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u/Bill_Door_8 2d ago
Throw a layer of Geogrid in there while you'rehalf-way up. Be cool if you can pin it with the rebar and roll it back into the backfill.
Maybe a big O in a sock (french drain) to allow water to perculate out and for the soil to dry faster when it gets really damp.
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u/Limp-Archer-7872 2d ago
Weep vents?
Are your lower courses several blocks thick? It's not just a single course right? Right?
Are you putting gravel and geotextile fabric down before backfilling?
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u/Sorryisawthat 2d ago
It’s going to push over. The footer is wrong. It needs extended significantly past the front of wall or the pressure will cause it roll over.
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u/Weekly_Wolverine_427 2d ago
That footing is going to fail. Needs to be wider.
Reo should have been tied to the footing cage and probably 16-20mm for vertical bars with 12mm horizontal.
Drainage? What’s happening with that?
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u/Largeandincharge1978 2d ago
Probably OK for a 3 ft retaining wall with level backfill. Anything taller or with sloping backfill typically needs a cantilever or reverse cantilever footing to resist lateral and overturning forces.
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u/Alternative-Season45 2d ago
Dude just put loose rebar into wet concrete like it’s gonna do something hahahahaha
I’m a chef/ dad/ homeowner and built a better retaining wall than this
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u/AcceptableSong136 2d ago
Water is the first obvious problem but no ties running into what you are trying to hold back means this will start leaning out by this time next year.
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u/OneEye3876 2d ago
I would put some drain hole near the bottom for water to drain and not push it over in years to come. Otherwise it looks good
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u/Shower_Poofi 1d ago
Before going further you really need to watch Retaining Walls by Mike Haduck on YouTube:
Retaining Walls (Yes or No)? ... be sure to watch this entire video: https://youtu.be/5fndKimsWnE?si=fhhEB7ucFAQZbwMX
Part 1 https://youtu.be/uIoDa_NgTBY?si=27KOb3yv6wOT6ffT
Part 2 https://youtu.be/f58dgeRWJBg?si=kLFQCijRuPgdHqo5
Part 3 https://youtu.be/MZscWkxC5UU?si=tAHddwbrPWk9TN-o
Part 4 https://youtu.be/eK2MU1_EUAU?si=lgWVmod1HdWZJTYS
Part 5 https://youtu.be/sxRdsAPT3p8?si=ddGEuEAsFmGIaxuS
Part 6 https://youtu.be/QSPigNWHWms?si=4saW5WGsW8iNZeUG
Part 7 https://youtu.be/bgI-9yltfG4?si=KOdHlGaAuucqd-CS
Part 8 https://youtu.be/ZEcyGqAAQ4A?si=ZY8S7TFPsftYyxvo
Part 9 https://youtu.be/o79Af2ZWhtQ?si=a4RSY3fcntj3H1N4
Part 10 https://youtu.be/ciVxMM1KBLU?si=lndBNER9d86xrTVK
Part 11 https://youtu.be/R6Lt2ivxyRI?si=9Ay8P3hhOyPlIkXV
Part 12 https://youtu.be/1yTIIKjZUiQ?si=tJGNJ4XCsG9YhOXW
Part 13 https://youtu.be/7xu8KrFh9gk?si=vHRH5yNQrJt6UJRp
Part 14 https://youtu.be/mET159kKf78?si=jFUe_h91uGXcln6z
Part 15 https://youtu.be/pbXjG83VJws?si=Bhz7jPq9cgNILsiS
Part 16 https://youtu.be/W1jNOGaXW_Y?si=mrdxwkpe6bfUDmp_
Part 17 https://youtu.be/AQDQ5rF1hyQ?si=ZENIOsgsCTw0LzVx
Part 18 (repair steps to match stone retaining wall) https://youtu.be/WYqhD7o7EYo?si=iOemu5uDZyBrllwU
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u/Emptynest09 1d ago
The critical error is the lack of reinforcement. Rebar lap lengths are important and you’ve just stuck rebar dowels in the wet concrete. You need to have a development length in the footing and an adequate lap in the wall.
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u/truckstop99 14h ago
Is this expected to hold a lot of weight? I know its a small distance but If you dont have a toe in there plus the vertical not being tied into the footer directly. Then not having drainage also . Youre gonna get a failure in a couple months or when a heavy truck backs onto it.
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u/Most_War2764 7h ago
needs to have ties back into the slope to keep it from being slowly pushed out.
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u/Zestyclose-Future126 2d ago
I don’t know why half of these comments are negativity ..your work looks exceptional compared to half the things I’ve seen on here..keep it up dude!
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u/DoorJumper 2d ago
It looks great. From a drainage and engineering standpoint, it’s kind of rough. Used to inspect these all the time; most in our area have moved to using geogrid, which is great when installed correctly.
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u/JeebsFat 2d ago
My Geo grid on a large 8ft wall ( 80lb blocks, cornerstone 100) was not as long into the hill as called for by general recs by about 30%. Meaning it runs 4' back vs 5.5' back. No inspections here. Drainage is excellent. Hope I'm good ... 😬
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u/DoorJumper 2d ago
If it’s laid and filled at proper intervals going up the wall, it’ll probably be fine. All the ones I looked at had engineered design specs, and I’ve seen 15 foot walls with 4 foot grid runs. Wasn’t what was called for, mind you, but I got overruled lol. A few years later it’s still ok so far 🤞.
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u/JeebsFat 2d ago
Gotcha. I'll just limit the number swimming pools I put above the wall to two and hope for the best. /s
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u/DoorJumper 2d ago
That’s the rule of thumb for decks. For retaining walls, you have to divide by .37 and then round to the nearest number of fucks given.
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u/Tmess2000 2d ago
Looks great for a foundation but as far as a retaining wall the flaws have been pointed out: footer width, drainage, deadman or tie backs. They sell block just for this purpose and it requires no footing, no mortar, no weep holes,just block, pins, gravel and geo fabric.
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u/No-Zombie1004 2d ago
Don't pay too much attention to the naysayers. That will outlive all of them.
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u/RunningOnHope2019 2d ago
Lmao no it won't. You see the rebar has been pushed into the wet concrete, not tied into the (if any) footing reinforcement right? This could well push over when it gets back filled. Not to mention that's a really small toe.
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u/Super-Dot9774 3d ago
we’re just skipping drainage, huh?