A Frameless Geodesic Dome (2013) | Hacker News Reader

A Frameless Geodesic Dome (2013)

rigsomelight.com

183 pointskarim94 comments

In order to shed rain and be fastened to each other, the plastic sheets overlap each other as shingles on a roof would.

OK, that's good; a reasonable approach to leaks.

It’s all held together with bolts that bolt through all the layers. The shell of the dome is about 2 1/2 inches thick.

That's not so good. Many potential leak points. Stress concentration at the bolt holes. The plastic may tear. Nothing holding the edges together with a tight seal. Almost all the problems with geodesic domes are at the joints. The author is vague about how the joints work.

Buckminster Fuller's concept for geodesic domes was that they were to be made from factory-built components and modern materials. They were to be products of the industrial age. In a factory, parts could be made to tight tolerances and be weathertight. With modern durable materials such as aluminum and Fiberglas, the domes could have long lives. During the 1950s, many such domes were built for radar stations. There are large radomes in the Canadian north abandoned decades ago, but still standing.

Then came the era of hippie domes, which were built by hand from "natural materials". This did not end well. The author of Domebook I and II has repudiated his work, after a long history of failed structures. Trying to shingle a sphere does not work well. Nor does trying to fit a standard window into a dome. Nothing quite fits, and there are too many bad seams. All this gave geodesic domes a bad name.

The domes in this article look like the ones from Dome Village in LA, but less rugged. [1] That was an attempt to house homeless people. The Fiberglas domes of Dome Village held up fine for 13 years; the project failed for other reasons.

[1] https://en.wikipedia.org/wiki/Dome_Village

> repudiated his work

Link? Are you talking about Lloyd Kahn? https://en.wikipedia.org/wiki/Lloyd_Kahn

Personally I think the best thing that came out of the geodesic dome movement was Steve Baer’s Zome idea from Drop City, and more importantly the Zometool construction toys, which should IMO be a standard thinking tool available in every middle school and high school math classroom. http://www.zometool.com https://en.wikipedia.org/wiki/Zome

Loyd Kahn wrote a few articles about the problems with geodesic domes, like this one: https://www.shelterpub.com/domes/#domebuilders-blues

Yes, that's what I was referring to.

Interesting how these objections are mostly about how domes don’t fit well into existing industrial supply chains and building codes which were designed around more conventional box shapes. That is, many of the problems are not with domes per se but rather with their inability to integrate well with a culture that wasn’t expecting them.

I’ve found the same to be true of many aspects of human culture and engineering: we stick to conventions often not because they are inherently better reasoning from first principles, but just because they are conventions. This makes the whole society more efficient, but also has a way of shutting down novel ideas and experimentation.

Preference for rectangles, boxes, and square grids is (in particular) one of the most deeply entrenched of our cultural conventions, very difficult to displace. We use them for basic measurement, architecture, construction, city planning, cartography, textiles, industrial design, packaging, visual art, basic instruction in math and physics, books, circuit board and microchip layout, seating arrangements, camera sensors, computer displays, and on and on...

Most of those problems are associated with small domes. As domes get larger, the edges get closer to straight and many of those problems go away.

Large domes are usually built with only the top third of a sphere or less. This generates huge outward stresses at the base, so there's a steel ring in tension to support them. This works fine. Often the outer walls are raised, so the dome doesn't go all the way down to the ground. This allows roofing a big area with a sturdy structure.

Syufy Theaters built many domed theaters around Silicon Valley. The original ones were radial, not geodesic - radial beams tied together by ring beams. The Houston Astrodome is a similar design. Although vacant and unmaintained, the Astrodome is holding up well. Later Syufy went with octagonal buildings, such as the Century Cinemas next to Google HQ. This kept their round branding, but allowed better subdividing into multiplexes.

This thing has no insulation pluming etc. It's basically just a tent.

Sill at 2100$ worth of materials it does not need to last very long and frankly he can toss a tarp over it if there is rain in the forecast.

> This thing has no insulation

It is literally made of insulation. You didn't read the article.

He actually mentions significant solar gain on a white structure with partial shade and minimal windows. This is a sign of an insulation problem.

3/4” blue-board foam on it's own does not provide significant insulation you can find better windows. A well insulated house is going to have significant air dead space etc, which makes a huge difference.

Re reading he used two layers of blue board, but I would surprised if he hit R-8 equivalent overall. That fluffy pink foam blocks you see people use are often R-19 and that's in addition to the rest of the wall in a normal house.

Though because it's such a tiny space it's still probably cheap to heat and cool.

Yeah, 1.5" of blue board is probably not sufficient. I imagine carving 4" blocks of foam to fit tightly together would be more rigid and weatherproof, but cutting all those angles just right is difficult.

except aren't all the angles the same? In that case, you make a jig..

It would require some custom manufacturing, but the bolt problem could probably be solved using a channel connector that runs all the way along the panel edges. Roughly something I-beam shaped, probably angled, probably with some kind of snap-on cover for the corners. Probably made of extruded metal or plastic, or maybe molded plastic but it'd be a big and expensive mold. It would be easy enough to caulk during assembly, if you're not worried about easy disassembly and reassembly.

Of course, this almost certainly exists already, would raise his parts count (though assembly would probably be easier than with the bolts), and couldn't be home-made. It's also not really frameless anymore, because the channels become the frame. (Not structurally though, so this is sort of a middle ground.) I could see this as being a pre-made kit which you'd add your own panel design to.

Factory tolerances are not the key ingredient for weather tight buildings. Water and air management at the joints is. Good management can be achieved by careful design or by proven practice. Proven practice is why shingles can be weathertight with only moderate attention.

The reason hippie domes leaked is getting the details right during construction is hard and foregoing proven practice makes it much much harder.

Like pretty much every machined building concept other than the mobile home, Fuller's ideas were unsuccessful. Mostly because building weathertight buildings is a solved problem. The solutions are just not evenly distributed.

There's a huge success story in machined buildings - Butler Buildings.[1] They have about 100 standard steel parts, from which industrial and farm buildings can easily be constructed. Rural America has millions of their buildings, from small sheds to large factories. They offer wall and roof sections with and without insulation. (Their site promotes the fancier options for schools, malls, and churches, but the volume is in the plain metal ones.)

There are competing systems, such as Behlen.[2] ("Good iron. GREAT experience"). All these systems bolt together on site, usually mounted to a concrete slab. Such buildings are dull, boring, weathertight, easy to erect, and durable. They're rarely seen in cities, so many people don't know about them. But get thirty miles outside a big city and they're everywhere.

[1] http://butlermfg.com/en/butler_systems_details [2] http://behlenbuildingsystems.com/resources/photo-gallery/agr...

Pre-engineered metal buildings [1] like those offered by Butler are an excellent form of construction for many applications. The components are fabricated using standard processes of the steel industry (milling, extrusion, roll forming, etc.).

To the degree these create a machined building in agreggate, then likewise the aggregate of dimensional lumber, plywood, OSB, asphalt shingles, gypsum board, concrete masonry, insulated concrete forms, etc.

[1]: For what it is worth most pre-engineered metal buildings in the US come from mom-and-pop shops rather than the big players like Butler because engineering is engineering and roll formed steel production is a commodity.

> Mostly because building weathertight buildings is a solved problem. The solutions are just not evenly distributed.

Yes, but these two things are connected. Cheap, fixed, weathertight buildings are a solved problem. But as soon as you fix a building to the ground, you enshrine a rent seeking opportunity, and that space will then be subject to market rates, which will make the resource unevenly distributed.

If we had cheap, mobile, weathertight buildings (and another of other mobile amenities around them) then you could decouple the living space from the market locked to the location, and you could get something closer to even distribution.

Utopia is trailer parks?

Trailers are probably not small enough, not cheap enough, and not easy enough to move around in tight quarters.

Also: "utopia" in this sense is just "provides a path for re-entry to society to homeless". Not some sort of grand remaking of the city.

This is cool to play with and all, but what rubs me the wrong way about posts like this is the delusional 'look I made something that is applicable as anything but a novelty! I'm solving major societal problems here!'. This thing doesn't have windows, it requires replacing panels on the outer shell every few years, you can't build up not even 1 level and has virtually no sound insulation so horrible in term of land use, doesn't have walls solid enough to put plumbing in let alone fix anything else to, doesn't meet any building regulation in terms of safety - not even if you take regulations from 30 years ago, ...

I understand the draw and see the romanticism of living like a hermit in a forest; really I do. But for some reason people delude themselves into thinking that this can scale. When you're saying 'I love nature so much, I'm going to go live right in the middle of it!', it's like saying 'I love my horse so much, I'm going to eat it tonight'. Which is fine - I eat horse meat. But don't claim you're 'loving' it in the same way normal people use the word 'love'.

Don't forget that bugs would get inside, that you couldn't have any reasonable sort of climate control, etc. Domes are cool for camping, events, and as very temporary emergency shelters, but living in one like this is not very sustainable. The Better Shelter exists and is a good product: http://www.bettershelter.org

FWIW it also says the "temporary shelter" produced by the organisation Better Shelter is intended to last 3 years (product page).

The Yurt seems to have been doing well, it's close to a raised dome, has replaceable modular construction, is easy to erect and move, has been tested for centuries (millennia?) in some of the harshest climate on the planet, namely the Mongolian steppe. In UK a few people use them as permanent homes.

They won't fit well in a rectangular road grid (unless you want to use the margins to provide outdoor space, eg for growing), but would pack in to a tri-/hex-grid.

Of course bugs might get in, just like a house in a Western city, seems a strange objection? Do you live in a cleanroom?

I can buy a metal garden shed for a couple of hundred bucks, assemble it myself, and it'll stand for decades without needing much if any maintenance. I could get one with a window, and a door that locks.

It wouldn't give me any Whole Foods cred like a dome or a yurt, but aside from that issue it seems more practical than either of those, if I wanted to live in one small and poorly insulated room without plumbing.

I've just looked at the Better Shelter page and it seems that their idea is the same as mine -- a metal shed.

There's looks like a good shed, extendible, more insulated than sheet metal.

The metal shed you get now, is likely to be designed to break and be hard to repair, 10 years ago its predecessor was probably much better.

At least their shed is designed with repairability in mind.

> I could get one with a window, and a door that locks.

For a couple hundred bucks?

Well, okay, closest I could find was this $279 one with a lockable door but no window, but I haven't looked all that hard.

Gers/Yurts aren't poorly insulated. They're actually a bit over-insulated for most places. You could easily add locking doors or plumbing (I've seen both in Mongolian gers), but the real design advantages are the portability and wind load factors.

Also, you can't put straight furniture against the walls. And it's difficult to stand near the walls.

If you build the dome tall enough it isn't really an issue. My dome is a 20' diameter 5/8 dome and my head will only touch if I am standing 4" away from the wall.

Each of the 15 sides is around 4' long on a 20' dome so you can put square furniture against the side if it isn't over 4' long. It is a problem with long furniture. I have an 8' long counter and I drop stuff behind it all the time.

On the other hand, you'd be surprised with how little you actually need in order to survive and live a peaceful, happy life. Building regulations are fine - if you wanna be a normal, living a normal life, in a normal society.

But the world is a pretty big place. We don't all need these norms.

You might have a morally authoritative view on just what basic needs a human has, and certainly can justify these requirements with a human ideal forged in your own social context, but the real honest truth is, most of those ideals are arbitrary.

A lot of people can live without windows, especially if they're surrounded by nature 100% of the time, anyway. Plumbing? Who needs it if the rest of your property is set up for it - not everyone needs to live a decadent western lifestyle where running water is on demand within a few feet of your sleeping area, etc.

A lot of the world survives just fine without all of these requirements, and from that perspective this "romanticism" is less of a fantasy, and more of a "what if .. we could live simpler lives, instead of more complex ones" - and that is the real merit of articles like this. To push us outside the "glass-half-empty/-full" norms that, ultimately, a lot of us are trapped in.

("Normal people use the word 'love'": Please tell me, what is normal. Because I don't believe you have a large enough sample size, honestly, based on your professed view...)

This 'hut' uses quite a few resources. I would not like to pay electricity bill in summer/winter.

> It has electricity and is heated with a single electric radiator and is cooled with an exhaust fan and small window sized air conditioner

It doesn't have to be though, depending on where you build. In my current climate, I could do all needed temperature moderation with clothing or blankets.

There's nothing simple about a dome made of plastic, though. It demands an extremely complex and polluting network of oil rigs, refineries, transformation, transport, etc.

If someone wants to live without the benefit of a whole lot of things which are really really nice to have, like plumbing, then they have my blessing.

But even if that is your desire, then a dome is a ridiculous way to achieve it, compared to a rectangular structure with a pitched roof, which is easier to build, more stable, is less likely to leak, will probably last longer, and gives you more efficient use of space and materials. Domes solve nothing.

Domes minimize radiative cooling per unit volume?

I think domes look pretty sweet, and that‘s reason enough to build them.

I think the author was very clear in his post that this isn‘t an alternative to a real house, he explicitely called it an „ephemeral“ structure, and he compared it to teepees and yurts.

I think this was a great article, and it feels like you are more complaining about a genre of articles instead of this article in particular.

Indeed my whining is about the genre, but I feel the author is making some broad claims about wider applicability, for example:

"The difference in the ability of these different structures to shelter and provide a nice place to live is dramatic."

(notice the words 'place to live')

"The frameless dome pictured above is the culmination of my experience with these structures. Three and a half years after building it I am ready to advocate it as an excellent alternative lightweight structure."

('advocating an alternative structure' - one doesn't do that about tents)

"I think this frameless dome balances many of the trade-offs of lightweight structures and arrives at an optimal structure that drastically minimizes construction complexity, time and price while maximizing livability."

(again, the reference to 'livability', and wording that suggests something more permanent than a tent, like 'structure')

These are just 3 sentences, but the entire first half makes claims that go beyond 'hey this is nice to go camping in' or 'you can sleep in your backyards for a few nights in summer in this'.

It's more robust than a tent, but not so much as a brick and mortar house. I'm not sure what you want him to call it, but for what it's worth, I certainly didn't read the article like a zealous advocacy piece.

It seems to me like this guy is just excited about domes, so I'm curious what background you may have that causes the article to poke your annoyance buttons.

OK I think reasonable people can disagree on what they take away from this piece. So maybe he meant this as a mere build log, and not to stimulate others to do this for anything but fun. In which case - great.

Where I'm coming from (the following is navel gazing, but hey, you asked :) ) is the plethora of people who 'advocate' things that they have only rudimentary experience with, and of which they fail to see the broader context if it were adopted on a larger scale. I especially experience this in 'modern back to nature' movement, but I guess it happens equally in software. For example:

- like here, people advocating flimsy alternatives to houses for permanent residence (simplistic car tire or rammed earth houses for example; not the real engineered type, but the 'let me get a few buddies and a crate of beer and I'll build a house over a long weekend' type) because they as a single male engineer with family who owns some land have managed to 'live' (read: sleep and code) in it for a few seasons;

- the rocket stove zealot, proposing that people use those for everyday cooking without making it part of their identify or self-worth;

- the 'self sufficiency' crowd, thinking they'll go 'live off the land' on half an acre growing some zucchinis and 5 chickens. Or in a log house in Alaska - which they have to build with 50 tonnes excavators and for hunting they need a rifle with a scope for which the lenses need to be cut in a vacuum lab for sufficient clarity; but hey I pulled the trigger so I'm self-sufficient amirite?

- part of the 'organic food'/'farmers market' cheerleaders. Look, I buy organic as much as I can; and I love farmers markets. But these are luxuries, they're not part of the solution for a 'sustainable' future. We can't feed that many people on inefficient agricultural techniques.

- the 'urban farmers' and related folk. I have a garden in an urban area myself; again, I'm not complaining about the principle. But thinking that this is something that can be upscaled as an alternative to 'traditional' agriculture is just silly; and sometimes dangerous when it takes away from real alternatives. In this category is my favorite idiot: the ones who go to town hall meetings to advocate for planting fruit trees all over town to feed the poor and the homeless. I have yet to meet a single one who has ever tended to a single tree, let alone one who has tackled the many problems with this on the surface great concept. But that doesn't stop them from pushing others to work on their braindead ideas, and thereby harming the efforts of others who have actually workable plans (which are less ambitious and nowhere near as flashy, but at least not doomed to failure).

I guess what I'm getting at is that I'm annoyed at people who assume that everybody else is an idiot, and that they're Gods gift to mankind who has come to tell the unwashed masses how to achieve enlightenment (that's not what OP was doing, just talking in general). Instead, have some humility, try to understand why things are the way they are, check if your proposed solution has the same problems others have, and if they don't, show that you've done your homework by pointing out how your solution is better than the others by highlighting them.

I really appreciate this screed. You're opinions here are obviously warranted. I'm wondering, though, do you have any examples of folks who do have "actually workable plans"? It seems to me that you've set a pretty high bar for what those types of plans are, and so I would very much like to know if you can reference any person or group who has met that bar. Thanks.

I like to think that the bar is actually very low. Like (moderate) people in a neighborhood proposing to maintain more natural-style parks but being held back because a city has to spend much of their time on and needs to CYA against foaming-at-the-mouth environmentalists who will never find anything good enough. Those moderates aren't as invested as the zealots, so they won't push very hard. It's the problem of the silent majority - people who don't really care but wouldn't mind are held back by those the few who are hardcore and don't think small progress is enough right away.

As for concrete plans - I've seen so many, but none of them are 'big' enough to really wow anyone. Small scale renaturalization projects being stopped because they don't provide the right habitat for this particular type of frog or whatever it was so now nothing's done at all and the whole coastline is eroding again (no frogs now either!); a pensioners' hobby group who build wild bee housing but the spots where those were supposed to be put wasn't optimal, so they were moved, demotivating everyone so the whole thing stopped. The 'fruit trees in cities' thing, drowning out those who just want something nicer than what there is now, and would be willing to invest some time or money, but not if it means arguing 50-page reports on why this tree over another. In all cases, probably if there had been someone with enough determination some solution could have been found, sure. What the zealots fail to recognize though is that they're only antagonizing those who would be favorable to a moderate version of their ideas, one that wouldn't cause them too much inconvenience.

Apologies for the glibness, but it sounds like you're a zealot for moderation?

On the meta-level, yes - one could say that I'm moderate on the matter at hand, but a zealot at the first derivative thereof :)

I sense a contrived 'calculus of epistemology' medium post in there... I'm sure it would do great on the upvotes on this site, too.

These examples you have are insightful, and they remind me of the saying, "the perfect is the enemy of the good." Zealots want the "perfect", and Moderates want the "good."

It does seem to me that you are working with a strong bias against environmentalists, though, and maybe it's because you don't consider yourself one?

I've been thinking a lot about identity, and how a lot of our interpersonal issues comes down to whether or not we see our fellow humans as "same" or "different". ... and I'm starting to understand that the important thing is to evaluate ideas on their own merits, and pay less and less attention to the individual putting forth the idea.

We're already working with a lot of crummy ideas that are in full effect (long dead the individuals having put forth those ideas), and now we have adherents of those ideas roaming about the world quite zealously.

But I don't blame the environmentalist for being an extremist. I think they rightly perceive the situation they find themselves in to be an extreme one. I'm glad they get to tell us about it, and happy when they are able to limit humanity's encroachment on a diminishing wilderness.

Lets not hang anyone for wanting their work to “save the world” or be important in some other way, even if it is naive.

What he does have is a cool temporary structure. Maybe it can be made into a commercial product for residential outbuildings or durable camps. Maybe other people can take this design and make it their own. Maybe it’s just a concept build, without a practical application but some hobbyist potential.

Either way, it’s a pretty cool thing to build or read about someone building. The “frameless” feature that he discusses is interesting. The simplicity is interesting.

This is true.

BUT that doesn't make this a terrible idea. I believe the famous Ikea flat-pack shilter[1] is the current state of the art in "emergency" (think refugee camp) shelter. This is certainly comparable.

[1] http://www.bettershelter.org/better-shelters-house-iraqi-ret...

I'm confused by your last paragraph. Living in nature, especially if you're trying to do it with a small footprint, is nothing like eating your horse.

To suggest that wanting to live in nature is to want to destroy it is a bit extreme. If you buy a massive piece of land, and build a house on it, you haven't ruined all of nature in your land. If you farm it, sure.

Back to the article though, I hear you in regards to "I've solved the world with this one idea" sentiment. I will suggest though, that missing from your first paragraph is any notion that people can live differently to the standard house or apartment. Some people live permanently in large rugged tents in mild climates that don't need much in the way of heating. Their showering done in creeks or lakes, their cooking done outside. Some people live permanently and happily in the back of vans, even utility vehicles.

Your complaints about the dome aren't unfounded, surely that's what most people would want so to suggest that the dome could solve the world's housing desires is obviously not correct. But it would be a more than whole and total solution for many people, even if it may be transiently.

I think the domes would make a great temporary structure for someone building a homestead though. Some people live in an RV on the property while they build up their home, which I assume is to skirt some housing regulations while they live on site.

"To suggest that wanting to live in nature is to want to destroy it is a bit extreme."

Well no, they don't want to, but they do it anyway - in the aggregate. Look, a single person living in a forest isn't damaging it; it's when many people want to do so, and actually do it, and the infrastructure required to live such a low-density lifestyle. The equilibrium is that almost all inhabitable land had people scattered all across it, along with a few high density cities for those who rather live close to people than have lots of room. But even those want to go to resorts in 'nature' on the weekends, so they still disturb and on the larger scale destroy natural habitats.

If you really care about nature, you go live in a city, and you stay away from nature as much as possible (with the exception of some reserves that could be designated 'nature recreation' areas; I'm not saying nobody should ever be in a forest).

Of course from the individual choice point of view it's more complicated; prisoners dilemma and all. My point is - if you live in a forest, you don't like nature (or at least, you're not doing your best to protect it); you like living in nature, which is different. And it's fine, I understand - but don't pretend you're protecting natural areas by living in them because you're the only one on your 10 acres. You're contributing to the destruction of habitats, biodiversity and most other measures of 'health of natural systems'.

The article mentions yurts and then goes on saying "at the same time the frameless dome provides a living area that is protected by a solid insulated waterproof shell. This is absent in these other lightweight structures."

I beg to differ! Yurts as used in Mongolia and Kyrgyzstan often have several layers, at least one of them being water-proof. The innermost layer is often wool, which offers excellent insulation and can be dried quickly when it gets wet from prespiration, offering some sort of climate control. Mongolians experience ultra harsh continental climate, going from -40°C in winter to +40°C in the summer, and they have used yurts for centuries.

Source: stayed in yurts in Mongolia, Kazakhstan and Kyrgyzstan for a total of several weeks on a motorcycle tour, went to a yurt market to check out the building materials in Ulaan Baatar.

The structure seems to be relying on bolts, plastic sheeting and foam for all of its strength. Even bolts are not usually considered structural elements, since the sheer strength of bolts is negligible - much less plastic or foam.

The whole idea of geodesic domes is that the trianglular sides distribute load more efficiently. In this case, there's nothing that could be described as load bearing. It's a semi-rigid tent that will disintegrate in a strong breeze.

If you're having problems finding a suitable frame for your geodesic dome, consider bamboo. There's a guide prepared by Buckminster Fuller himself at http://www.desertdomes.com/bamboo.html and Mitra Ardron made a variant with continuous poles at http://www.mitra.biz/joomla/blog/2815-instructions-for-makin... (are there metric versions?)

I have few questions:

    - Is it livable in temperate zone (-20°C in winter)? 
    - Is that single sheet plastic window? How does it insulate in winter?
    - Is it dark inside?
    - Can plants survive inside?
    - Building codes usually have minimal volume for bedrooms, does it meet those standards/recommendations?
    - What's 2x4?
    - What's blueboard?
    - Post some closeup pictures of doors, windows, top and base from the outside
    - How do doors open?
    - Why the working table have so massive bottom? Is it just "art"? Seems like it's unnecessarily heavy.
    - Wouldn't mass-produced triangles be simpler/cheaper?

Also I just noticed article is from September 2013!

Also previous HN discussion: https://news.ycombinator.com/item?id=6355488

A 2x4 is a piece of lumber that measures around 2” by 4” in depth and breadth (in reality, it’s slightly smaller) and is often used for structural work.

(it’s slightly smaller if it is planed)

I genuinely hate that I'm going to say this, but... A 2x4 is 1.5" X 3.5" It's not _approximately_ 2x4 or _slightly_ smaller than 2x4. Not that this adds critical information regarding the article, but if you set out to work with 2x4s and assume they are 2" by 4", you'll be sorry. And yes, I have made that mistake before, but it's a mistake you only make once.

The lumber is cut to 2" x 4", but then it is dried causing it to shrink to "about" 1.5" x 3.5"

Wikipedia's page on lumber[1] is a bit more rigid:

Today, a "2×4" board starts out as something smaller than 2 inches by 4 inches and not specified by standards, and after drying and planing is reliably 1 1⁄2 by 3 1⁄2 inches (38 mm × 89 mm).

1: https://en.wikipedia.org/wiki/Lumber#North_American_softwood...

This is not correct. The standard construction 2x4 you buy at any lumber yard/home improvement store is specifically cut to 1.5" x 3.5". Of course wood naturally expands/contracts depending on the environment so it will never be exactly those dimensions, but quite close (+/- 1/32" I'd wager).

Likewise with plywood, most (but not all) plywood sold in the US is actually slightly undersized. 3/4" is normally 23/32" thick, 1/2" is normally 15/32" thick, etc. This isn't because the wood shrunk (though again plywood will slightly expand/contract depending on the moisture of the environment), it's because the manufacturers meant it to be a little thinner.

There are still manufacturing tolerances for both types of products, but the lumber mills know what they are doing, they know what their customers require and provide tolerances that match those. Just imagine one very common usage: a deck. You think deck builders would be happy if the dimensional lumber wasn't a) very consistently the same thickness and b) very consistently the same width? Otherwise you'd have a very bumpy deck that looked pretty irregular.

I genuinely hate to go and measure my lumber but anyway I just did:

Unplaned 2x5 measures exactly 2" x 5" Planed 2x3 measures 1 15/16" x 2 13/16" Planed 2x4 measures 1 7/8" x 3 3/4"

I'm in Norway. Apparently it's country specific.

In Norway construction lumber is usually specced in mm, e.g. 48x98mm, which is smaller than 2*4 inches. People still call it 2x4 though...

2x4 in this context probably refers to the size of the cross section, in inches, of the timbers in the floor structure. Floor joists are horizontal supporting members that run between foundations, walls, or beams to support the floor. 50mm x 100mm for the imerially challenged.

There's no way you could live in this at -20 degrees without heating.

Note: Do not use an open flame or heat source inside an enclosed space made from polyurethane/plastic/nylon

See: Agonising death

Isn't there a pretty good chance that the horrible plastic smoke will make you pass out before the death kicks in, making it just terrifying and brutal but not agonizing?

I've seen the results of tents catch on fire - I don't know about the panels in the dome in OP's link, but certain plastics etc can burn extremely quickly. A normal pop-up tent will burn to the ground in a matter of seconds, cocooning anything inside in molten plastic.

I can believe this. I used to work in "the Warehouse" (store name, rather than what it was). We were told that if there was a fire, particularly in the areas containing mostly plastic, we were to get out as fast as possible, no heroics, no trying to put the fire out: just scram. One of the larger buildings they owned caught fire a few years before I started, and had burned up by the time the fire department got there.

Show HN: Years ago, some friends and I designed & built a dome/hexayurt hybrid[0] for Burning Man. The walls are made of insulation sheets and the hinges are taped with 6" bi-directional filament tape (many here will know Hexayurts[1], I'm sure). Additionally it has connection-edges which feature a system of fabric-strips and 2" velcro to connect edges reliably. In total it consists of 3 separate, foldable pieces that can be set up in ~20 minutes by 2 people, even in windy situations. It has 2 "windows", the pointy things on the sides. The door is a bit small and definitely requires some flexibility getting in and out :) It survived the harsh desert conditions of 3 years at Burning Man so far, incl strong winds and rainstorms, only requiring a bit of tlc between each year. The "strap-down-spider" tightens the structure down against winds and keeps it firm enough that you can easily lean against it. To make it fully rain-proof, one needs to tape the floor-tarp up against the walls (visible in the pictures). Apart from the floor-taping the setup and tear-down is entirely zero-waste, due to the velcro system. Hexayurt enthusiast might notice the silver tape that covers the filament-tape seams, which helps protect the tape from deteriorating in the UV light (w/o the silver tape, the filament tape would go brittle after abt 1-2wks of direct sunlight).

Here[3] is some very outdated documentation on the first version. We initially tried to connect the walls via bungees - didn't work out at all as you can imagine. The following year we added the velcro system after I found this amazing post [2] on a hexayurt mailing-list, describing someone's experiments with materials. Without that person's efforts and time spent on research I could have never finished this one!

Of course there's already a bunch improvements lined up for a v2 - hopefully next year :)

[0] http://imgur.com/a/8K1dR

[1] https://en.wikipedia.org/wiki/Hexayurt

[2] https://groups.google.com/d/msg/hexayurt/2QRUl3txk-8/v_A0DDc...

[3] http://flo.jottit.com/moonberry

Neat! Nice work

Does it stay livable in the Nevada desert sun? What's the interior temp in the afternoon

Thanks! During peak-temperatures of the day it's definitely warm inside, yet cozy/cool enough to have a nap. Also kept the warmth inside at cold nights.

From what I gather, it's made from plastic, foam and wood, and uses electrical heating. I didn't see any mention of fire risks, which is something people have brought up before with these structures. I hope there's at least a fire extinguisher in there.

As an exercise in low-cost structure construction this is interesting, but this is not a practical home. It apparently lacks any kind of sanitary facilities or kitchen. As noted in the blog itself, it's comparable to a tent in terms of applications.

> The geodesic dome is brilliant in how it minimizes the amount of materials needed to enclose a given space.

Except sheet material is sold in rectangles, so you end up with a huge pile of offcuts.

As a child I was entranced by geodesic domes in the late 1970s (part of the hangover of the utopian back-to-the-land movement), and I read up on them extensively over the following decades.

I've also done a bit of construction.

Domes are wildly impractical for almost every purpose.

Yes, the hold more volume per surface area. That's great for a liquified natural gas tank. It's not so good for humans who live on flat surfaces.

They are very hard to plumb and wire.

They generate tons of waste.

They are hard to maintain.

Roofs and walls have different purposes (structural support vs shedding preciptation) and different materials are best for each.

The list goes on.

I could write a 500 page book on why domes are almost always the wrong answer, but the shortest proof I have is: if they were so great, they would have caught on.

The only success stories I have heard about with respect to dome construction do not use any sheet material at all.

They use inflatable forms, flexible basalt fiber composite rebar or basalt reinforcement mesh, spray foam, and gunnite (sprayed concrete).

As far as I am aware, even those still have moisture problems.

As mentioned by parent, the article includes cutting patterns for rectangular sheets. All the edges and corners are waste. Every edge is a cut. If you make a dome shell out of panels, you have an incredibly high amount of joints and cracks for that volume, and every one of them could move water or air through the wall. The article itself mentioned that polypropylene breaks down in UV. Maintenance.

So I guess the intrepid geodesic dome builder should sew a big balloon out of pentagonal and hexagonal nylon panels, inflate it with one of those bounce-castle blowers, and spray it with gunnite. Then saw through the top of the shell and add a stick-built cupola for ventilation control and roof pitch. You lose the portability, but if you really need that, most people make do with a tent. Those come in dome shapes, if you really need your living space to be round.

A large-scale 2 dimension version of this was built for Terminal 2E and 2F at the Paris CDG airport. It yields the same feeling of airiness and I'm always happy to transit though that one.

https://www.flickr.com/search/?q=cdg%20terminal%202e

Note that this design requires impeccable material strength characteristics. Otherwise it will collapse, as 2E did in 2004:

https://failures.wikispaces.com/Terminal+2E+at+Charles+de+Ga...

I'm left wondering about moisture. Ventilation seems pretty minimal and, inside the walls, nonexistent, so how long until this has mold all over it?

I did not understand how it is completely waterproof. What if there is rough weather? And how does it prevent water from entering in case there is standing water around the base?

There is a platform under the dome to prevent standing water from entering it. Further I would expect it would be best to build on a slight rise to mitigate this issue. As for the waterproofness of the shell, as long as the higher panels overlap those below them by a sufficient amount (maybe 10cm) then the dome will shed water in even heavy storms.

one problem i've run into when making a shed is the flooring. unless you spend a huge amount of time+effort+materials on a foundation, water vapor tends to come up. This causes mold growth and eventually over the span of 5 to 10 years the floor will rot out of under you. (I'm in the Pacific Northwest)

Does anyone have recommendations on a cheap moisture tolerant flooring? I am thinking of using Marine-Grade plywood as a subfloor on my current project.

This reminds me of Dome of Visions, which has now come out in 3 iterations.

http://domeofvisions.com

This is Bruce Hauman's dome (creator of the Clojure library Figwheel)

I watched a video of the talk where this dome is mentioned last week.

https://www.youtube.com/watch?v=j-kj2qwJa_E&t=9m16s

I was hoping there'd be some more info about the way he lives in general. Seeing from the outside picture he also seems to grow his own food.

Hexayurts[0] > Domes

0: http://hexayurt.com

(sorry, I don't have time for a more detailed post just now).

Would you save much on materials by removing the lowest tier of sheets? You'd lose standing room near the walls. Would you lose strength?

Didn't Halliburton make a line of urban survival domes to go with their bubble suits and management leisure suits?

https://www.youtube.com/watch?v=JzSMjSxM5Vo

https://www.youtube.com/watch?v=k_dg6V8pQGo

Great idea and execution. I did not find any mentions of a toilet in there, did I overlook something? How is this going to work?

Given the portable nature of it, a toilet is not more than a bucket. Otherwise it would require one of those expensive permanent installations for waste and water. You do not want such a bucket inside if you can avoid it.

I also found myself wondering about running water

I’d expect that you’d go outside for such needs.

You could spray this with layers of gunnite and build up a sealed concrete bubble. I think it'd be just as stable as an inflated form. Once you had an 'eggshell' layer of concrete, that would bear the weight of successive layers. Might require taping over the edges of the 'shingles'.

A similar idea, but edible. http://www.marthastewart.com/913141/sugar-cage-jacques-torre...

There was another with Jacques Pepin, that I am unable to find, where explains the concept better.

This puts me to mind of a Bill Burr quote, about the real desire for guys to spend $250k on a house.

Tax appraisal: cost of structure $2100, cost of land $100k. Tax bill: half the cost of structure per year plus school levies.

Not sure why you‘d use expensive land for a structure like this. You could build this pretty much anywhere, so you could go for cheap land that‘s not suitable for normal homes.

Because you'd like to have access to public transportation or bike to work?

Right, but you could get a parcel of land that‘s very small, or steep, or otherwise unusable for normal homes. Depending on local regulation, you also might not need a building permit, or there might be a simplified procedure since it is very small and/or temporary. (For example we have a lot of „green land“ in Austria, where you are not allowed to build. For this reason it is very cheap. But you can of course erect a tent on „green land“.)

could you lay the shape out flat first then pull it all in.

i would have 3d printed (or laser cut) something first.

Reply on news.ycombinator.com