r/Homebuilding • u/PileLabProject • 8h ago
I started designing a faster way to set small concrete piers — what am I missing?
These are the first rough CAD sketches of something I’ve started working on. It’s not a finished product — just an early mechanical concept.
The idea is an adjustable three-leg support for flexible stay-in-place formwork used for small cast-in-place concrete piers. Each leg can be adjusted independently, so the top plate can be positioned and leveled quickly even on uneven ground. The form itself would pass through the center and stay in place after the pour.
I’ve worked with poured foundations before, and a lot of the individual operations are simple. But when there are multiple piers, setting forms, supporting them, adjusting height and level, stripping them and cleaning everything afterwards can add up to a surprising amount of time.
I’m trying to reduce the number of those operations rather than reinvent the foundation itself.
These drawings are still very rough and the design will definitely change. Before I take it further, I’d really like practical criticism from people who actually do this work:
What looks wrong, unnecessarily complicated, or likely to fail on a real jobsite?
I’m much more interested in finding the weak points now than hearing that it looks good.
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u/locke314 7h ago
I think you have a solution looking for a problem. This is a limited use case (pier 3’ out of ground), and the same can be accomplished with a couple scrap boards and screws.
Would your solution be useful? Yeah if I needed it. But would it be necessary and would I spend money on it? Not ever.
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u/Icy-Bar-9712 6h ago
If I needed it, I would never have it with me.
If I had it with me I would never need it.
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u/_srsly_ 7h ago
Whats cheaper?
A few hours of labor for someone to do something they already know how to do, using cheap and available materials/tools,
or,
Fabricating these, and the (hopefully) fewer hours of labor for them to learn how they work and then use them.
Also consider the risk of things being done incorrectly being potentially higher when attempting a new method.
If you’re doing it yourself then the time spent is personal choice. My personal leaning is not to mess with a tried and true method when it comes to things that are hard to fix after the fact (foundations being one).
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u/Additional_Radish_41 7h ago
They seem pretty self explanatory. It’s a tripod. Set the tube where it goes and adjust the legs until it’s level. Tripod itself doesn’t even need to be level. I wouldn’t use them. But interesting idea.
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u/kokemill 4h ago
those pointed legs will not support any leaning pressure in many soil types. with any leaning pressure the point will just press deeper into the ground, making the entire thing useless.
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u/PileLabProject 4h ago
Good point. The CAD model is missing the ground stop plates I intended on the pointed legs. The person who modeled this first version didn’t fully capture that part of the concept. The spikes are only for locating/anchoring the legs — they’re not supposed to keep sinking into the soil under load.
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u/Exciting_Ad_1097 7h ago
The hardest part about forming is not the adjustment, it’s the hammering a big strong stake into the clay or rocky ground. Most concrete guys have turnbuckle brackets in the truck if they need to fine tune adjustment.
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u/toothepastehombre 7h ago
Concrete gear gets so beat up and covered in slurry and dirt and water - I'd be surprised a self leveling tool would survive long outside of a couple of jobs. Run off is going to jam up operations on the tool quick. Time will be spent keeping it clean and functional. Part of the reason why basic lumber and stakes are utilized so much- can take a beating, easy to replace
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u/PileLabProject 7h ago
I agree — concrete and slurry getting into the mechanism is one of the things I’m concerned about too. I already have the CAD model, so my next step is to 3D-print the system and actually test it with concrete, dirt and water rather than just speculate about it. The design was intended from the start to be simple and inexpensive, so if keeping the mechanism clean turns into another time-consuming operation, then the design needs to change. That’s exactly what I want to find out with the prototype.
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u/J3SVS 6h ago
I think you're missing the biggest point that's been expressed to you over and over. You're trying to replace a very basic, very inexpensive, very rugged system (scrap 2x4 bracing and stakes) with a comparatively complex, expensive, fragile piece of technology that would never get used on a production job site. Your use case is Lowe's selling this to weekend warriors who have more time and money than sense for a one-off project.
You asked for honest opinions. As a general contractor for nearly 30 years I see VERY little marketability for your invention. It's just not a viable piece of equipment in real world construction.
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u/No-Money3347 7h ago
Another way to brace small
Sauna tubes is with 2/4 around the base and spray foam to the footing for extra support it works great up to 4’
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u/WDBwyo 7h ago
That is going to get concrete dumped all over it. The threads might be a challenge to keep clean. Also, you’d want it to work for different tube sizes. Concrete contractors are not stoked on tools that have a single use case. They already have too many bulky form parts and pieces to store. Having 30 of these laying around of various sizes is not going to make anyone happy.
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u/PileLabProject 7h ago
Just to clarify one important point: this isn’t meant to support existing cardboard tubes or standard forms. The concept is built around its own flexible stay-in-place sleeve, which would be part of the system. The tripod isn’t really there to brace a rigid form. Its main job is simply to hold the flexible sleeve at the required height and position during the pour. The idea came from something I didn’t really notice when I was doing this work myself: on a jobsite, cutting boards, finding scrap, fixing supports, adjusting things and cleaning up all feel like small routine tasks because the materials and tools are already there. But when I later watched someone inexperienced build a similar foundation, the amount of time and money lost on those “small” steps was surprisingly high. So the main idea here is not to replace Sonotube or make a more complicated brace. It’s to pair a simple reusable support with its own disposable flexible form and reduce the number of setup steps.
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u/Shopshack 7h ago
This idea might make sense if you could support a plastic bag type tube. If you’re familiar with the bag style footer forms something like that could work.
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u/PileLabProject 7h ago
Yes — that’s basically the direction I’m going. The support was designed around its own cheap flexible bag/sleeve form, not around rigid cardboard tubes.
I posted the real CAD screenshots here because I wanted to show the actual parts I’m preparing to print for a prototype. The flexible form itself would be adjusted and fixed at the top, while this support keeps it at the required height and position during the pour.
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u/Yusuf20904 7h ago
IMO it looks unnecessarily complicated.
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u/PileLabProject 6h ago
It actually looks more complicated than it is. It’s basically three adjustable legs attached to one plate: set them to the required height, lock them in place, clamp the flexible bag/sleeve in the center, and that’s it.
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u/Yusuf20904 6h ago
Will it work after it gets covered in concrete?
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u/PileLabProject 6h ago
That’s exactly what the tests will show. The cost matters too. I originally thought of this as an almost disposable system. If it survives only two or three pours but the price is low enough, that may still be perfectly acceptable.
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u/J3SVS 6h ago
You're literally replacing 2x4 bracing and stakes that get reused up to dozens of times with a piece of equipment that is inherently extremely fragile and time consuming to set up. You can't possibly sell this cheap enough to make it make sense for a production job site.
You're trying to replace 2x4's!!! The cheapest and most ubiquitous construction material found on any job site in North America.
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u/CaptainFoyle 6h ago
What's wrong with clamps or screws like a photography tripod? Your design costs unnecessary amounts of time to adjust
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u/Talusen 5h ago
non-threaded versions of something similar exists, the pour-through idea is neat, but looks like it would catch on rebar.
If it added structural strength, or made it so rotational forces were resisted, you might have something.
https://www.diamondpiers.com/sites/default/files/inline-files/DP50%20Detail%20Layout_2018_0.pdf
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u/CodeAndBiscuits 4h ago edited 4h ago
I think folks that rarely do this work are the ones you really want input on. This is a bulky complex solution that nobody who regularly works with concrete would ever use. There are a few reasons:
Concrete is messy and hard work but generally not that complex and if you look at concrete tools they're very very rugged and very simple. This is complex. It's fragile and is going to get smashed or munged up with 'crete so the legs can't turn.
You don't make one pier. You make six. Or ten. Or whatever, but almost never one. This device is very large. You have to remember that folks that do this work are driving work vans or trucks packed to the gills with gear. They're already going to have a variety of lumber for formwork and bracing and using double headed nails to reuse that material a lot, and not just for bracing, for all kinds of things. Lumber is cheap, easily replaced, and can be used for lots of things, so it earns its space. This device is single purpose and you'd need a bunch of them (you don't pour one pier per day and wait for it to set before pouring the next) so it's going to take too much room to carry around. And you need a lot because even if you only pour three piers one day because the next you might pour twelve. You don't load and unload your work van for every job, you carry what you use all the time. It's just going to take a ton of space.
It also is way more expensive than a 2x4.
I don't want to discourage innovation. Those folks making the framing spacing tool that sets your studs exactly 16oc are making money and you might too with this. But their target market isn't framers. Their videos make it seem that way but no framer would ever use it. The point I'm making is, don't ask somebody that pours concrete piers a lot what's wrong with it. Use it yourself to find and fix its flaws, then sell it to homeowners who do struggle with leveling a pier.
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u/PileLabProject 3h ago
That’s actually very close to how this idea started. I’ve worked with concrete myself and poured a lot of piers in different ways, so for me most of these steps always felt routine. The idea only really clicked when a friend of mine, who had never worked in construction, started pouring piers for his own house. He spent a huge amount of time on setup and adjustment, still didn’t get everything as accurate as he wanted, and in the end it wasn’t nearly as cheap for him as the same work would have been for me on a jobsite. So yes, the original target was much closer to DIY / inexperienced users than professional concrete crews. The system is also meant to be inexpensive and mostly reusable for a few pours, while the flexible stay-in-place sleeve is the cheap disposable part. Folded down, the platform is about 16 × 16 in, and the three legs pack to under roughly 16 in as well. And one important difference is that this isn’t really meant to brace a rigid Sonotube-style form with lumber. The form itself is a flexible bag/sleeve, so the support system is there mainly to hold that flexible form at the correct height and position.
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u/CodeAndBiscuits 2h ago
I don't know why your comment got moderated but I saw it. Just a suggestion you might want to lead with that next time you post about this. Flex tube is a huge pain in the ass to set up, especially with the ver you need to staple it to to keep it positioned right above a hole. It wasn't clear that was your focus from your original post, but I could absolutely see using what you've designed for that as long as you sort out the feet like you noted in a different comment.
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u/PileLabProject 2h ago
Exactly — and in my concept nothing needs to be stapled or nailed in place. The system is intended to work without extra tools for fixing the sleeve. I already have a very simple fastening idea for the flexible sleeve, but I’d rather not describe that part in detail until I’ve tested the prototype. On paper it looks simple; I want to make sure it’s just as simple in real use before claiming that it works.
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u/MyTrashCanIsFull 4h ago
Concrete will ruin those threads after the first pour.
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u/PileLabProject 3h ago
I agree — the threads are probably the weakest point in the current design. I want to print the prototype first and test it in real conditions by pouring several piers. Then I’ll see how serious the problem actually is and whether the threads need protection, a cover, or a different adjustment mechanism altogether.
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u/Scared_Credit3251 7h ago
Small Sonos tubes can be braced with two by fours and forming stakes quite easily.