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Note: This page is very much related to Hexayurt Thermal Analysis.
The Panels[edit | edit source]
There are a few materials to make Hexayurt panels:
- Hunter XCI 286 - Much like Tuff-R but *VASTLY SUPERIOR IN EVERY WAY* - much stronger, more fireproof, will last for years. This is The Way. -vg
- Tuff R/Super Tuff R - Quick-and-dirty units constructed directly from materials purchased at Home Depot or Lowes. That's what we did at Strong Angel.
- OSB Board - with precision cutting of angles for tighter assembly. That means a table saw. Ideally we'd find a local wood shop and have them cut for us because: I'm, er, not the guy to be doing that work, and keeping my fingers!
- Dow Thermax HD - Higher spec materials which may need some wrangling to obtain. Two or three inches thick, better foil facing, generally much more like what you'd use in disaster relief situations.
- Hexacomb cardboard - (http://hexacomb.com/) which can be manufactured on site from flat pack core materials, so the 1"x4'x8' board is made from a core about two inches by six feet by one inch, and a couple of rolls of foil. Hard to explain, see the "Rapid Deployment Concept" page on http://howtolivewiki.com/hexayurt/
- Waterproofed Triplewall Cardboard - Weyerhauser has a really good waterproofed triplewall cardboard, as used in the Global Village Shelters. We're trying to source some but having problems, but of all the materials, it's probably the one closest to spec for developing world use if somebody wanted to start making units ASAP.
- Honeycomb Polypropylene - usually sold as a flexible mesh which will need to be glued to two facers to form a sandwich panel, but karton dot it has a material called exalite which has this done already, and looks like a good choice for hexayurts - but untested!
Plywood / OSB[edit | edit source]
https://web.archive.org/web/20100712052444/http://opensourceecology.org/weblog/?p=340 - $132 plus paint for 166 square feet. Unbeatable. and there's a ton of unedited video and pictures here:
http://www.files.howtolivewiki.com/open_source_ecology_plywood_hexayurt_build/
I think there's scope for an approach here where there is no flashing used, but (for example) the roof triangles over-lap a few inches at the center of each triangle and screws hold the boards together, and at the roof edges, the roof goes over the lower of the two boards comprising the roof triangle, and is screwed directly into place. Could be hell to waterproof, could have structural problems, but my intuition is that there's an approach here which does plywood with no fasteners beside screws/nails which might be very useful for some circumstances.
The Dow Route[edit | edit source]
The first is a Dow insulation product. You can pick Thermax, Tuff-R, Super-Tuff-R or anything else they have at your supply store. They all work more-or-less the same, just some have a thicker, more protective foil surface. You want 1" or thicker. 1" is just fine. There are parallel products from other manufacturers. RMAX is the most common insulation board used at burning man-- the silver stuff that's tan in the middle.
You can see from the video that the panels made of this stuff are very light, fairly strong, and easy to work with. Note that the edges of each panel are taped. Tuff-R/RMAX is dusty, nasty, and at no point to be cut on the playa for it is sacred to the gods of moop, shedding copious amounts of nearly playa colored crap all over the place. This is bad. It is also hairy with fiberglass, dozens of threads per inch of board. You can cut it with a craft knife, or you can cut it with a saw that has an excellent dust collector, but in either case, be aware and take care of your lungs. Gloves, N95 dust masks and goggles are recommended.
Anyway, for these reasons, you will see the edges are fully taped. No moop gets out, and no fiberglass makes your fingers itch on the playa after handling the boards. Take a look at them in the hardware store. They're not bad to work with, it's not evil stuff, it's just not cotton or wood. It's a technical product.
Pro: Cheap ($15 a sheet approx.) Easy to find. Easy to cut, easy to work with, insulating and robust. A perfect material for the job you want to do in the Black Rock Desert.
Con: It's basically polystyrene with fiberglass added, meaning you'll want a dust mask, and you'll want to wash your hands/arms after cutting it to avoid irritation.
Make no mistake, this stuff is environmentally questionable unless you treat it responsibly and reuse it many, many times.
Making a more reusable Hexayurt: Hexayurts could be cheaper. And again: this material isn't super eco-friendly, unless you re-use the hexayurt many times (or you put the insulation into a home that's being built). According to the eplaya discussion boards, there's a decent period of re-use on even the standard R-Max type boards. The less accessible improvement is Thermax HD. This is the same stuff, but it has a thicker layer of foil akin to a soda can. This stuff will last a good long time. It's more expensive per sheet and usually requires a special order, therefore you have to coordinate with another hexayurt builder to buy about 30 sheets and split them or something. Seriously consider this if you can be so organized.
Now, an aside here. Plastic is, when respected, capable of being a very environmentally friendly material. Tupperware, for instance, does a job that no non-plastic material I'm aware of can: it stores food in a robust, reliable, reusable and sanitary way. Glass breaks in your bag, a thermos is expensive and usually full of something already and is bulky and costs 20 times as much. Compare to a yoghurt container, used once and abandoned. Tupperware is a good use of plastic, as far as I can tell, because the plastic is saving resources every time it is used.
So if you're going down the insulation board path, be sure that you take good care of your Hexayurt, and use it for many years, or pass it on to somebody who will. You can also reuse the insulation board in home construction projects because the design specifically tries to keep the building materials relatively whole. This is the correct way to bury your Hexayurt - in the walls of a building, keeping other people (or yourself) warm and dry in a permanent dwelling.
The Hexacomb Route[edit | edit source]
Hexacomb is what the first hexayurt ever built was made out of. Hexacomb for the structure, and R+Heatshield as the insulating layer. R+Heatshield is about $0.25 a square foot and is completely lightproof and reflects away 97% of the heat of the sun. Very useful to cover tents and cars with.
Hexacomb cardboard is a miracle product. It's an inch or more thick and looks a bit like corrugated cardboard, but it is stronger and lighter because instead of little ridges, the interior is filled with hexagonal honeycomb cells. It looks like a bee hive inside. It can be recycled and, for playa use, burned (if you must!) Better to reuse it, of course.
It can, however, be tricky to find distributors for Hexacomb. I really like this material, but it's just not as easy to find as the Polyisocyanurate. My expectation, however, is that if and when we go to mass production of Hexayurts, it will be a hexacomb-based board we use to make them. Great stuff.
If you would like to really go the Green route this year, I would recommend getting together with other Burners and putting in a bulk order for Hexacomb cardboard. Please contact me if you are interested in doing this, and I will put you in touch with the supplier, or you can contact them directly.
It's more hassle, but it's the right thing to do.
Corrugated Plastic[edit | edit source]
This is generally not a recommended approach because for most applications, polyisocyanurate boards with aluminum facing are a better bet for long life and insulation properties. However, should you wish, here's how to do it.
I had a little think about coroplast again, and spotted two things I have missed the first time we looked at coroplast.
We can now offer a pre-fab or field-fab hexayurt which folds up very much like the existing folding units. The mechanism might change just a little on the roof.
As a bonus, the coroplast hexayurts can be fastened with pop-rivets rather than tape, which cuts the price even more. Pop rivets are five cents each, and we'd use one about every six inches. They go in with a cheap manual tool or a power tool.
The trick for strength is that for the roof, where two panels come together, you take about four inches of each panel and make a crease. The panels are put side by side, with the 4" strip bent up at 90 degrees to each panel, forming a fin.
Those fins then re-enforce the roof from wind loads.
That fin - that vertical ridge - is then folded over in half, forming a 2" fin - and pop-riveted in that position. This connects the two panels, and and produces a structural reinforcing fin which is also watertight because there is no route for water to enter the building's roof, except by going up the fin, through the tight folds, and into the building.
A similar approach can be taken at the roof edge, incidentally producing a Rainwater harvesting gutter if done right.
Taking down the hexayurt would be a matter of using bolt cutters on the rivet (light ones, maybe even tin snips) or just ripping the rivets through the material - note the holes would only be in the fins.
With a little additional work, I'm also pretty sure we could make this entire assembly fold. There might be some fiddly little cuts or creases in the coroplast to make it work, but nothing you couldn't do with a craft knife or a hack saw. We could also spec an 8' roof pole to go into the center of the space, which removes all and any structural issues about the coroplast permanetly by putting it in tension, and it will simply never tear in that configuration (*very* strong in tension). I should have thought of that before.
Or consider the IcosaPod direction, and use ?triangular? box girders on the structure. They could, for example, be fabbed on the edge of each panel, or possibly done as separate items. Might be a good way of getting the roof pole also.
Other Materials[edit | edit source]
There are a lot of other materials that we have not tested. The 6' and 6' Stretch Hexayurt designs are much more forgiving, so if you want to try Coroplast or Triplewall corrugated cardboard or something like that, consider a test run on one of them first. One material you should not use is plywood, or any other heavy building material. The strength-to-weight ratios of plywood does not work well with the Hexayurt design. It's too heavy. They could hurt somebody.
Roof[edit | edit source]
Leather can be used on top of the OSB roof panels see the 2008 Hexayurt at Open Source Ecology.
Improving Sturdiness[edit | edit source]
The pointy ends of the roof pieces are pretty fragile particularly when moving and setting up. Foot-long pieces of sheet rock corners (the light-weight metal angles, about an inch on each side) taped along the side near the point make them very sturdy and only add a bit of weight.
Similarly, pieces could be added to the corners of the square pieces to keep from denting the corners when moving.
Install both with duct or strapping tape before you tape the edges, then tap lightly with a mallet to make it flush. Then proceed with the edge taping.
The Tape[edit | edit source]
The other key material involved in constructing Hexayurts is tape. Specifically, 6" wide bidirectional filament tape. In English, that's a six inch wide tape with re-enforcing fiberglass strands running in both directions, so that it will not break or tear under almost any imaginable circumstance, including howling playa dust storms. It is amazing and very expensive. Other tapes have been tried-- they aren't great in playa conditions, and those who went off the beaten path regretted it. Some innovations are underway and we'll see what results come back. BTW: don't use duct tape at Burning Man, it just becomes gray goo. There have been some people who say a 'flashing' product called "Vycor" or bituthene tape will be indestructable, but it is opaque black, is even more expensive than the bi-directional tape, and is thusfar untested for hexayurts (if you've done it speak up on the talk page). Additionally, we've got a totally new option gluing strips of vinyl on to create hinges the same way the tape is used, see vinyl below.
The bilfilament tape does not last more than 1-2 weeks of playa heat and sun: it gets crusty and peels off. If you make any permanent hinge or connection with the bifilament tape, it's recommended that you cover it with a layer of foil tape to protect it from UV damage. The foil acts as shade. It's also shiny silver and looks pretty cool, and it should keep your hinges in perfect condition for years to come.
3M 8959 at 6" wide. This tape has also been found as T.R.U. FIL-835, which is the same stuff. You will note that 3M does not give you the option to buy it in that width on their web site. See the playa checklist for even more about this specialty tape and where to find it.
3" tape is half the cost and has its uses on the hexayurt: many steps are perfect for 3" tape, and it's easier to work with than 6" tape. Using 3" tape means you need to be much more precise in the construction process, but is otherwise perfectly viable. You can also save tape and money this way: get a roll of 6" tape from the supplier above. Slit it in half the long way as it comes off the roll. Hold the roll and press a razor blade against it while a friend pulls one 3" wide strip off at a time.
Foil Tape: Time to use some foil tape! This stuff is fairly inexpensive and comes in a variety of widths, we recommend T.R.U. AF-20R it is also available more readily than bi filament tape. It's also very forgiving to work with and is designed to decrease fire risk. Foil tape is ideal for certain steps, but not all steps of construction:
- Foil tape to tape-seal the edges of the panels.
- Foil tape is NOT advised for making tape-hinges or for the connection of panels to each other, or the "tape ring." You need the bifilament tape for this because you rely upon the strength of the filaments and the stickiness of the tape.
- Foil tape is highly recommended to protect the permanent tape-hinges used for semi-folding hexayurts in the camp-danger style or mitered styles.
Foil tape is easy to find in 2" widths. 3" widths are a little easier to work with. For a 'standard' hexayurt roof (H12, H15, etc), you'll need to cover 114 feet of tape-hinges, but the tape hinges are 4 to 6 inches wide. So, remember it's 114 feet, multiplied based on the width of the foil tape (3" tape means 114x2. 2" tape means 114x3.)
The tape needs another layer of protection from the elements if you expect to leave the Hexayurt up for months or years. Foil tape is one good option. There may also be paints which are appropriate.
You can also see the Tape Spreadsheet in the additional resources section of this page. It explains why you need all this tape, and also how much tape you need for manufacture, and on each subsequent building use. Some great providers of Bidirectional tape are:
- Tape Providers -> Bidirectional filament tape, 6", Aluminum foil tape 4" and also they had created a Bundle with both tapes at a discount. Tape Providers also, sell this on Amazon but the price is better on their website
- T.R.U -> Bidirectional filament tape, 6" wide. Available from DistributorTape (ABT TRADING GROUP, Inc.), or by phone at 1-786-565-9858. Also available at Amazon: T.R.U. FIL-835B/D.
- Ideally we need a one-stop tape; a duct style waterproof, bidirectional filament tape with a foil face.
- People are adding some reflective tape to their Hexayurts and it looks awesome
Vinyl instead of Tape for Tape-Hinges[edit | edit source]
This is a brand new idea (as of 2013), has been tested in fire, in the sun, etc, as well as at Burning Man 2013 and 2014. Vinyl is a great way to make the permanent hinges of the Camp-Danger type, and possibly for sealing the exposed edges of the panels (although foil tape is probably way simpler to use). Here's the whole explanation on vinyl, brought to you by Jacob Rodriguez.
Plastic-Hinged Hexayurt[edit | edit source]
Andrewed says: Here is a prototype of an OSB hexayurt made with permanent plastic hinges. Worked really nicely.
4 roof panels and 2 wall panels, all with miter-cut edges, are joined permanently, Danger Hinge-style. Then these sub-assemblies get assembled into a complete building with the "opening" hinges. See each picture for detailed caption.
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Roof before raising
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Opening hinge
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Completed Hexayurt
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Hinge demo
The plastic hinge is made from propaflex. See:
propagroup.com > impact and handling problems > propaflex
It comes in rolls with the thin creases running perpendicular to the length of the roll. I just cut it at every second crease to make the hinges.
It is cheaper than standard plastic hinging and it works. It is a little weaker, so I worked out a trick to prevent tearing at the ends. Just trim the end of each piece so the thin, bending part in the middle sticks out beyond the thick flaps, like this:
___ ______/ | \_____ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |_______ | ______| \_|_/
Floor[edit | edit source]
Raised & Leveled Sand/Earth + Sheet Plastic or Tarp + Insulating Board + Plywood or Board (+ Carpeting or Mats) (Toczko Floor1)[edit | edit source]
The idea is create a level, dry, insulated floor that will support the weight of furniture legs and appliances, etc.
- First, to keep water out, prepare a level raised sand or earth surface, surrounded by rocks, cinder blocks or other material to keep it from spreading out. A ring of cinder blocks or rot-resistant wood staked in place with pieces of rebar would work. This is where the walls of the structure will sit, and where water will run off away from the structure, so we want the edge of the wall to be at the outer edge of the raised surface. Place the outer edge level. Fill the cinder blocks with sand or earth, if we are using blocks, and then fill the center area with sand or earth and level it with a long straight piece of wood, or scrape the high areas with the edge of a sheet of plywood until the floor is as level as we want it. (If you think that later on we will wish that we'd spent more time leveling the floor, then do that now :)
- The next layer is a one-piece sheet of plastic to keep moisture out of the structure. It doesn't need to be strong thick plastic because its not going to be exposed to wear and tear if we use the insulating board and plywood layers. if the plastic is going to be the top layer then yes, we do want the strongest plastic sheeting or tarp we can get. The plastic should extend out over the edge of the floor, and over the edge, to let water run off and away. (I'm assuming a tropical rain forest in a typhoon, or a winter flooding rain storm that goes on for a week. The sort of conditions that warrant building emergency shelters.)
- The next layer is insulating board, if we are in a cold environment. In a warm climate we probably don't need this.
- Plywood or board layer. This can be cheap thin sub-flooring, or scrap 2x4, or any flat material strong enough to support a furniture leg pressing on it. This could also be optional if we aren't going to be using that kind of furniture, or if there isn't any insulating board layer.
- Comfort layer: Carpeting, mats, blankets, etc. Whatever we have on hand, or whatever we want to use and can plan for.
If we make this floor with all the layers we have a surface that feels and acts like a standard Western floor: Carpeted, warm and dry, that we can sit a chair on and rock back and not poke holes in the insulated floor.
1 First described to me by my friend Greg Toczko as a geodesic dome floor.
