Introduction: Cement Dome Garage

Picture of Cement Dome Garage

My old garage was too low for my latest vehicle to fit through the door.  I decided to do a more tried-and-true design with a simple dome, using rebar and nylon-cement (nylon fishnet and cement).  

The floor slopes a little, so I can roll out of the garage before starting up the engine.  One avoids breathing some exhaust that way.  Also, if the battery is low, I can push start it easily  just letting it roll out of the garage.  

The roof is treated with a cement-base sealer called Thoroseal, which is then protected by a layer of colored cement.  The sealer and color coat can weather away slowly, but they doesn't peal or blister like paint and elastomeric sealers can.  I am very happy with the longevity of that system.  

I decided not to do an electrical installation, since I have electricity nearby and extension cords.  There is a round skylight, a recycled glass table top.  

I decided to not put any doors on the garage, but I did set gate hinges into the sides of the door opening in case I change my mind in the future.  

Step 1: The Old Garage -- Demolition

Picture of The Old Garage -- Demolition

The old garage was made for a lower vehicle than my present one.  It was an experiment, using "nylon-cement" (nylon fishnet and cement) to make a roof without using iron rebar.  The fishnet was stretched out like a tent.  Peaks were formed where the tent poles were.   After plastering the fishnet, the poles were removed.  

Cement is good under compression and bad under tension.  A dome is all in compression.  This old roof had a complex form, like an egg crate, that was not as simple to visualize.  There were complex curves everywhere, but cross-sections sometimes resulted in lines that arched upward (resulting in compression) and sometimes downward (resulting in tension).  Any point on the surface was often a result of both factors.  

Just like an egg's membrane can hold all the broken pieces of eggshell together, I imagined the fishnet would be strong enough to hold the form together in case of cracking.  It did.  There were a lot of big cracks, though.  Since my present vehicle didn't fit in the door anyway, I decided to scrap the old garage and build a new one.  

In order to drop the roof, I broke the cement all around the top edge of the walls.  It didn't fall until I went back around and cut all the fishnet with a machete.  

Step 2: Site Preparation

Picture of Site Preparation

I was nearing the end of my fishnet reserves, discarded cargo nets used by tuna boats for unloading their catch to the docks.   Starkist Tuna, my source for fishnet over the years had moved off the island, so no more netting could be expected.  Fortunately, the old nylon-reinforced floor was still useable.  I eventually just did a mortar topping over the whole floor area, without using more fishnet.  On the walls, I had to use some sun-damaged fishnet, but it was still strong enough to support the wet cement until it hardened.    

You can see how I cut into the dirt to extend the floor area.  The shallow trench is for the foundation.  It doesn't need a massive foundation, because the thin-walled construction is relatively light weight.  The walls will be only about 1 1/2 inches thick.  

Step 3: Painting the Rebar

Picture of Painting the Rebar

One problem with iron-reinforced cement construction is that the iron can rust, expand and break the cement.   To help minimize that problem and add longevity to projects, I paint the rebar now.   Best is to use a coat of rusty metal primer, and then a good rust paint top coat.  

Painting rebar with a brush can be very tedious work, so I invented a way to run the smooth 1/4 inch rebar through a paint bath to quickly paint it.  The dip tank is made of 3/4" PVC pipe.  The rebar enters one end, is forced to pass through the paint, and when it exits the other end, it passes through a silicone rubber tip that scrapes the excess paint off and keeps it inside the dip reservoir.    (See: ). 

For heavier rebar with the textured surface, I put it on a waist-high work rack and paint them with a small paint roller.   

The 3/4" EMT drying rack is made of welded "H" sections of pipe with vertical "hinge pins" to connect them.  The units can be reassembled into other configurations for craft fair displays, etc.  

Step 4: The Rebar Goes Up

Picture of The Rebar Goes Up

The rebar is tied together at intersections with galvanized wire.  I buy the wire in rolls by the pound and use a good pair of lineman's pliers for cutting and twisting the wire.  

Basically, you just start at the bottom and work up.  The more rebar and the more tie wired intersections, the stronger the structure becomes.  

I do all the wire twisting on the inside, to prevent wire snags on the topside, that interfere with stretching out the fishnet later.  

If you want to put in electricity or water lines, now is the time.   I decided not to.  There is electricity nearby, and I have extension cords, if I ever need work light at night.  There are lots of rings in the ceiling from which to suspend lights, so the situation is very flexible.  

Step 5: Temporary Roof Supports

Picture of Temporary Roof Supports

I used bamboo for temporary roof supports.   You need the supports in order to walk on the rebar to stretch the fishnet, and plaster it.  Basically, you step from the top of one bamboo pole to another.  It's a bit like standing 10 ft. up in the air.  

There is some danger involved, so move carefully.  

I notched the tops of the bamboo for the rebar to fit into.  I also drilled the bamboo and wired the tops to the rebar, to make sure the bamboo stayed in place.  

Step 6: Stretching the Fishnet

Picture of Stretching the Fishnet

It is easier to cover large areas with one huge piece of fishnet, than to patch with smaller pieces.   A friend helped me pull it tight and wire it down to the rebar.   We spread out a big piece on top along the center line and rolled it down over the sides.  

Step 7: Plastering

Picture of Plastering

Plastering is done in stages; usually two coats inside and two coats outside.  The mix is three parts of sand to one part of cement.  A 50 pound sack of cement roughly equals one 5 gallon plastic bucket, or 6 shovels full of sand.  Add more, or less water to get the consistency  you need.  Wear rubber gloves, because wet cement is caustic to the skin.  Everybody around here mixes cement on the ground with a shovel.  

The first step, using rubber gloves, is to rub cement through the fishnet from the outside to stick it to the rebar.  That way, whatever you do to one square in the grid doesn't affect the neighboring squares.

Day one: plaster the outside as high as you can reach.   Day two: plaster the inside.  Day three: stand on a drum and plaster the outside as high as you can reach.   Day four: stand on a drum inside and plaster, etc.  

When you get to the roof, you have to start walking on the tops of the bamboo to spread out the cement.    Little by little, work toward the center.  

You don't have to finish the first coat completely before starting the second coat, from the bottom up.  Eventually, you can start walking on the cement.  

The skylight has clear silicone rubber stippled to the bottom side to make a frosted glass effect.  The topside of the glass gets algae growing on it in our climate, so keep the topside free of silicone for easier cleaning.  The glass is just glued in place with silicone.  If you set it directly in the cement, heat expansion differences may cause the glass to crack.   (A photo of the skylight will be added soon.)

Step 8: "Painting" the Structure

Picture of "Painting" the Structure

I have found that, indoors, spiders don't like raw cement.  If you paint the interior with house paint, the spiders come and you have cobwebs to deal with.   I just mix cement (gray or white cement) with powdered pigments (sold for tinting cement) and use that instead of paint.  It lasts a lot longer and is a lot cheaper than regular paint.  

I hate elastomeric roof sealers.  Once you paint your roof with elastomeric sealer you can never get cement to stick to the roof again and you are trapped into potential elastomeric nightmares over time.   Instead, I use a cement base sealer called Thoroseal.  It never peals or blisters, but does weather away gradually from sun and rain.  The Thoroseal is expensive. To protect it, I then put a coat of colored cement over it, like paint.  The colored cement is a cheap, sacrificial layer.  When I see white Thoroseal showing through it, I know it is time to apply more colored cement.  

I use broom heads as brushes to paint with.  For the final touches, I sometimes splatter on more diluted solutions to get mottled color effects.  

For more painting-with-cement info see:


Akin Yildiz (author)2014-09-23

very cool, back to the cave ages, Flintstones houses and garages everywhere !!

diy_bloke (author)2014-04-13

Great Stuff.
I enjoyed the discussion about the codes but guys, you have it easy in America. Where I live (Europe, Netherlands) there ar codes for everything, even if it doesnt have to do anything with safety, and if it isnt a dutch code, it is a european code.
We have rules about the maximum with and height of doors INSIDE your house. I can imagine rules abt the minimum measurements but the maximum?
If I want to add a water fawcett to the front of my house, a rule determines it has to be in a recessed metal cup. There are rules about the color of your house and about the color of your roof, rules abt the maximum height of a garden shed you want to build, rules abt the particular type of brick you want to use.

Although I havent seen zoning rules yet -as in some american cities- where there are rules abt the height of the grass in yr yard or the type of plants you may use.

sbusic1 (author)diy_bloke2014-04-30

Now you see why our ancestors fled to the "free" world.

diy_bloke (author)sbusic12014-04-30

wise decision :-)

Thinkenstein (author)diy_bloke2014-04-13

I take it life is not a Swiss Family Robinson experience in most places. For freedom, you pretty much have to live alone in the wilderness. As population gets more condensed, I could see more call for rules.

I'm thinking along the line of termite nest cities, or termitopias.

I think that all of the permanent construction in termitopias should be coordinated collectively, and not be privately decided. Probably, some general rules to follow would evolve out of experience. Which rules get engraved in stone, or enforced by law should be for demonstrable reasons of public good.

Height of doors might not be a problem if there are no doors, only tunnels and rooms of different height. If you need temporary doors to subdivide areas, you can hang them from the ceiling, along with temporary walls and curtains.

Anyway, with foresight and planning we could probably take care of everybody's needs cooperatively. If the city is your roof, you don't really have to worry about shelter from the elements as an individual. You do maybe have to worry about over-population -- getting too far ahead of your abilities to deal with things.

diy_bloke (author)Thinkenstein2014-04-14

I am much more a loner than a termite. I'd feel very unhappy there

Thinkenstein (author)diy_bloke2014-04-14

It would be nice if there was always a place for loners. Frontiers are rather scarce, though.

Eventually, it might not be a matter of what we want, but what we have to do, and whether or not we can find a comfortable relationship with the rest of humanity while we do it. A more cooperative spirit might be good for starters.

hardlec (author)2014-04-02

As nylon net is not availible to me, would hardware cloth work?

Thinkenstein (author)hardlec2014-04-02

The traditional technique, ferro-cement, uses three layers of chicken wire to hold the plaster. Rectangular wire mesh doesn't stretch in multi-directions, so cylinders are possible, but balls aren't. Chicken wire has a hexagonal mesh that stretches better. It takes three layers to have a dense enough mesh to hold the cement. Also it helps to have two people working, one inside and one outside to help with the squashing down of the mesh and passing through the tie wires. I prefer the finer size mesh, used for chicks.

pheenix42 (author)2013-06-15

I seriously wish the building code here in my town would permit something like this--but, everything must be according to squares or rectangles apparently!

Thinkenstein (author)pheenix422013-06-19

Yes, the codes need to change to accept this. Sounds like a bigger battle than I would want to take on alone. One of those "somebody should do it" things that will probably never get done .

jacobbrunberg (author)2013-01-06


Izusu Trooper, 1986.

Lokisgodhi (author)2012-10-15

The good thing about building codes is that they protect against unsafe designs and shoddy workmanship.

The bad thing about building codes is that they have become make work rules for local contractors and manufacturers.

Building codes are good for standard inside the box conventional construction techniques. They don't do very well for unusual or innovative design and construction like straw bales, underground architecture, cordwood masonry, earthship and the like.

The biggest problem is that most of the people who are doing the enforcement are not engineers and are basically just going through checklists to make sure everything that's on them is in the construction.

I'm an advocate of trying to get the big national codes that most localities follow to adopt specialized alternate codes for the various schools of alternate architecture.

That way when someone wants to build one, it' has it's own alternative code and you don't have to try and explain what you're doing to the pinheaded drones with their checklists. You just tell them to turn to whatever page of their manual, go get the alternative code that's to be used in that situation.

Thinkenstein (author)Lokisgodhi2012-10-15

Standardization of exceptions to the rules. I like the idea of alternative codes.

Lokisgodhi (author)Thinkenstein2012-10-15

Writing them is fairly easy. It'd be getting the ICC to adopt them that's the hard part.


spark master (author)2012-03-18

First I must say it is very very cool, then I must ask, do you live in a place with building codes and enforcement?

Too bad you didn't do a video as this was so very interesting and well made. I also think adding electrical pvc piping,(or whatever the codes ask for in embedded electrical conduit) inside the structure in a coherent design along with a conduit that terminates inside and just outside the building would let you (or your heirs/new buyers) put in electric. Also if you used galvanized pipe and mud boxes they last forever and will become structural.

If I could get away with it I would build a small out building like that, but sadly they would come down on me like white on rice where i live (near NYC)

Nice project and plenty of pics, please do a clear video tour of it.

I must also ask did you give it "horns" at the ends on the edges in the front?

Yep, there ain't much freedom left in civilization these days.

I don't have a video camera. Maybe someday I can do a house tour video.

The "horns" are sort of like oriental eves on a false front.

Well to me they are hornish, but I see where you were going with that , I did wonder actually. As far as building codes go they are there for a reason. Sometimes they are silly and picciune and must have been put there to make a contractor or manufacturer happy, but in general they are pretty good.

Again spiffy project you coulda made a gopher or something since it has a critterlike shape being mostly freeform. elongated domed and from behind has ears or horns.

Disney got nothing on you! Viva la Cementa!!

actionjksn (author)spark master2012-03-19

@ Sparkmaster So you think it would be good if the the government told him that he can't build the structure he wants on the property that he payed for with the materials he payed for? People in America and elsewhere have grown too comfortable with the government taking their freedom and regulating every aspect of their lives. The US government would not allow that structure to be built in America, and the reality is the building is perfectly safe. And if it falls in on him it's his building and his business. But it won't.

rapier1 (author)actionjksn2012-03-19

First off, he is in America. Puerto Rico is not a foreign country. Second, believe it or not you are *not* free to do whatever you want on your property because, shocking enough, we all live in a community and society in which the actions of one person can effect others. I live in a urban neighborhood of three story brick row homes. If the guy next door to me decided that he wanted to add an extra two stories made out of used shipping pallets and rust nails do you think I should be okay with that? It's his property, his materials. Would you be alright with that? Obviously not. So the basic concept that anyone should be free to do whatever they want on their property doesn't hold up.

Also, his actions can have a direct financial impact on you and I. For example, lets say he decided to build a house this way. His back of the envelope calculations are off and it collapses in a hurricane. Assuming it is insured then you and I get to pick up the tab for that through our premiums. Likewise, if he is injured you and I get to pay for that as well. A safe, well built structure that meets code for an area ends up keeping insurance companies hands off our wallets. This, in part, is why building codes exist. I'm sorry if you don't see it that way but that doesn't make it any less true.

Your actions can have primary and secondary impacts on those around you. You are not a rugged individual living apart from society. I'm not advocating some sort of nanny state that imposes draconian and kafkaesque rules but some common sense and understanding that there is a bigger picture is helpful.

actionjksn (author)rapier12012-03-19

First off, I'm fully aware of the status of Puerto Rico. I proposed to my wife on the beach in San Juan and she even did a presentation at the university there. It's my favorite vacation spot. And since you don't know I will tell you that they still have a certain level of autonomy even though it is still a part of The United States. Which means they get to decide weather they want to dictate what someone is allowed to build one their own property or not. And the government of Puerto Rico has chosen not to dictate how people chose to build a garage on their own property. I have no doubt that the Puerto Rican government would prevent somebody from building something that would be an eyesore in a neighborhood with a bunch of fancy houses that didn't have a sufficient buffer zone to hide it. But if it's not hurting anybody then they don't seem to mind.

The concept of building codes seems great an all but. it has reached the point of being draconian in this country. I am a remodeling and restoration contractor and I can tell you that they will stop you from building something that is safe and will not hurt anybody. And no I don't have any trouble doing work that passes inspection I have been jumping through their hoops for a very long time. But I also work on old houses that are well over 100 years old and the original work would not even come close to meeting the current building codes. But after 130+ years they are still holding up perfectly well. Building codes were supposed to do things like, stop people from adding on an extra two stories with shipping pallets and rusty nails. I can assure you they have progressed way beyond that. I know some city's that make you pull a building permit just to install a screen door. You think they're worried about safety? Oh yes I'm sure that's why they mandate that. I'm also pretty sure you would think building permits for screen door installations is a fantastic idea.

So yes I think you do advocate a total nanny state that imposes draconian and kafkaesque rules. I suspect Thinkenstein found it refreshing to be free from the rules and regulations of the nanny state he was dealing with. Plus Puerto Rico is such a beautiful and amazing place anyway. How much you want to bet when the next hurricane hit's Puerto Rico his little Flintstones garage will still be standing?

rapier1 (author)actionjksn2012-03-20

Yes, you sussed me out. I can't wait for faceless drones to dictate every aspect of life to me. It's gonna be great. This ability you have to see into the hearts of men and know their iniquity is astounding. You're kind of like the Shadow that way.

So can you tell me what city requires a permit to install a screen door in an existing opening on a residential structure? I'd love to read that code.

21cmcgyver (author)rapier12012-06-03

We got codes like that here in the peoples republic of california. And I am not exactly living in a metropolis, I live in far northern valley of california. There are lots of building codes for things like screen doors, window screens, outdoor fixtures. You name it and there is a code for it. In fact there is even building codes that dictate that you have to get a permit to change your bathroom faucets!

spark master (author)rapier12012-03-20

he lives in virginia beach and bought in years ago. I laughed my butt off when he told me. If you live in a place like Salem Mass you will find that you are very restricted by local ordinance on paint color and any minor facade changes. They do it because they want the same character as it had in 1800's. I heard about it as the owners paid a gent to depaint a few sections to get layers and samples . So they could prove that a house built in 1800's could easily have such garish colors as purple and black and lime green. and any combo's. Personally I think the restrictions are ludicrous in most cases and I swear it is a way for someone to get paid off. In Salem it that they want to to look like what people perceived as the quintessential "New England" fishing /whaling town and of course where the Pilgrim landed and the Witch trials. It is big business, (for them).

In Queens to avoid having a new building inspection and recertting the home, builders and owners would knock down every wall in a building EXCEPT the wall with the electrical service, then take a cape and rebuild it as a McMansion on a relatively tiny plot. After the struture was completed you ripped out the old wall and redid that as well! The code was changed so you can't do that anymore.

Where I live there is a 25 foot set back rule I do a renovation I can't build any closer to the street then 25 feet. Now, where I live people do not "sit" on their front porches (well most did not have them at that point), or on their stoops. If you did people walking dogs would stare at you (i kid you not). we put a tiny porch on our home and I tell you we get stared at at times. I would rather have taken the front out another 4-5 feet and then did the rebuild, But it would have taken a year to get permits and god only knows who I would need to grease to get the variance.


to keep the "Leave it to Beaver" look and feel. If you ever saw "Everybody Loves Raymond" I live about 10 minutes from that town and there homes are a little more spread out but essentially the same. That is where all the cess pools were dug in as when this place was laid out there were no town sewers.

I want a brick oven, let me explain I will never get one, since I can spend about 300 dollars (or so) in fees inspections and then they will raise my taxes.What I spend on the oven is enough. I may build one on wheels and document it here, just to not have issues with my town.

"how can you tell a politician is lying to you?" Answer "his lips are moving"

Old concept, "if there is 1 lawyer in town he dies a poor man, if another moves in they both get rich!"

but anyway there are good reasons for building codes, and my feeling is if you live in a rural area and what you do can only kill you and your kids, let it be. But you should not be able to sue anyone over it a death resulting in your own lack of ability and having the brains to look at something and not see obvious risk. Every year people are killed at amusement parks and their parents sue. Then the argument is "well they let him ride it, he should have told me no more forcefully. I have seen many people argue with the parents at Hershy Park argue scream and threaten when little chukie or charlene is a half inch too short for a certain sized ride. Part of me want them to have to sign an affidavit right there and then let the kid on.If the kid gets sucked out of their seat and is killed too bad.

but lawsuits are useful and can be used for good like changing the way business works.

Other times it may not be so clear if a test case is bull or real.

see http://ww w. lectlaw.c om/files/cur78.htm

and back to this garage, it is very cool and if I ever have a big enough piece of dirt upstate to build one I most certainly will.

actionjksn (author)spark master2012-03-20

Yeah it's a really cool structure. If I had a place out in the country I would love to build one but it wouldn't fly here in the suburbs. I agree with some places having building codes in principle but, it has reached the point where it is no longer about keeping people safe or keeping them from getting screwed by contractors. It is now just an extortion racket. I'm a contractor and the things that are required goes WAY beyond just looking out for the public safety. If you look at what they require permits for it is obvious that it's just a scam. What the government does is they find an area where people need protected. Like from from shady contractors. And then they go completely out of control as quickly as possible. And because there are situations where protections are needed they can justify all the other situations where they are just ripping people off. The same thing happened with OSHA. Workers safety was being jeopardized by shoddy employers who didn't care if people lost a limb or their life. So they start OSHA and it seemed like a great idea until, they got way out of hand too. Now they will go around and hand down huge fines for dumb stuff that isn't even endangering workers. It has become just another government scam. You know why? because none of these government agencies have any accountability. They will tell you right to your face that they are held accountable and that they just exist for the safety of the public. But if they were really held accountable and had to explain all of their actions to knowledgeable honest, common sense people who have power over them and who say " Now why are you doing this, and what specifically will happen if you don't do this thing that is costing citizens all this money "  I can tell you they would never allow themselves to be put under this kind of scrutiny.  Because they know what would happen, they would loose their gravy train.  As a contractor the things I see are just unreal. This stuff was supposed to do things like stop someone from building someones structure that maybe needed 2x10 joists to cover the span and load on something instead of letting them use 2x6 joists  without joist hangers.  Now they want to tell home owners how they are allowed to install their own door or window or insulation.  But if the homeowner wants to install it wrong it's their business. But not according to the government.  The funny thing is I've had to fix crappy work that passed an inspection many times. OK I guess I'm done venting now.

Thinkenstein (author)actionjksn2012-03-20

High five!

If there were no building codes then most cities would have huge fires and other disasters. Building codes are for closely inhabited places so that if there is an issue it does not effect anyone else. If you live upstae NY (I am close to NYC), one can build pretty much whatever you like however you want, in most places. But When you go to sell the property a mortgage provider may ask it be certified by building department as safe or removed. EVEN THOUGH it is an out building.

Will it be standing after a hurricaine, perhaps or perhaps it just surfs down a super wet river of must since it doesn't seem to have a foundation (perhaps not as well). Then if it impacts a neighbor, let the lawsuits begin.

And we have not taken up esthetics, which comes in in many places like VIRGINIA , where you can do pretty much anything you like. But if you live where my relatives do you have interesting restrictions. Front doors must be white , trees may only be planted in center of yard, which is where pools are allowed, so pick one. They had a few wacco restrictions .

My reason for asking the question is quite simple, I wondered if the local building inspectors bothered with this thing what were the restrictions or requirements. I think 1-2 of them would be awesome shelters for picnic area and you could have multiple door ways and 1 huge open side.

Thinkenstein (author)rapier12012-03-19

Quite true! In the bigger picture there are no frontiers left. The only way to accomplish anything new and original these days is through committees.

Yes, the building codes have reasons for being; mostly to protect the many from the few who don't know what they are doing. As far as strength goes, however, it is hard to mess up with domes. I imagine, as far as strength goes, I have done over-kill with my designs.

The triangle is an important element of flat plane architecture. I would say that complex curvature is the most important element in the strength of domes and dome variations. Columns, if not obvious can be represented by vertical bends, or folded planes. Anyway, you can work in the elements of traditional design, too.

It "termite nest cities", or "termitopias" as I now think of them, there would be freedom of design for everybody, but since cement more or less immortalizes the shape, the decision as to what gets cemented would be a communal decision. People who grow up in the culture would acquire a feel for what works, I think.

HI Thinkenstein,

I only take 1 exception to what you replied here, I don't think most people know anything when it comes to construction of anything other than salami provolone hero's . I worked for years in construction and saw so much stuff that failed (eventually) it was frightening. Pure crap done fast and covered over before anyone could see it. Some by contractors a lot by owners.

I think your dome is cool, if I ever have property upstate when I could make one of these I will. Read old Mother Earth News editions with earth sheltered or domes stacked wood/concrete domes/structures.

You could have put a pattern of clear bottles (glass) open side into the structure) in the walls and had glass block light. Clear wine bottles are great if you live near a bar/bar/catering hall that goes through a lot of wine.

enjoy it !

I probably don't get out enough to fully appreciate how unwise the general public is in do-it-yourself construction matters. I can probably accept your perception in that matter.

The bottle houses I have seen tend to have a lot of broken glass sticking out. I don't stick glass in cement unless I set it in place with silicone as a buffer to expansion differences.

The comments about codes here have been interesting. It's kind of another, "Can't live with them; can't live without them" situation.

rapier1 (author)Thinkenstein2012-03-21

Basically the general public is incompetent. My house was 'rehabbed' by the previous own in 1987. When I tore out some of the dry wall to get to a window he covered over (why? He just installed that window and then dry walled over it) I took one look at his framing and had to basically rebuild the whole wall. In place he obviously ran out of the right lengths of 2x4 so he lapped some of them by a few inched, drove in some coarse drywall screws and said "Good enough!". In another instance I had to take a ceiling out due to water damage. First off he laid on around 1/2" of joint compound to texture it (poorly). Then the drywall framing was 14' lengths toenailed into some headers. No cross beams. He didn't tie the frame into the damn joists. Nothing. When I started pull the ceiling down the whole thing bounced up around 1.5" as I took the weight off. This is *minor* in comparison to what I've seen elsewhere. Go to,,1220600,00.html and look at what some people are doing. Trust me, codes and inspections are not a bad idea for most of the public.

Thinkenstein (author)rapier12012-03-21

Somehow, I have a feeling that there would not be as high a level of common incompetence if people were making cement domes, like this, instead of traditional wood construction. I think the technology is simpler, and more foolproof.

As far as design errors go, especially in communal construction as in termitopias (termite nest cities), before the cement goes up, there would have to be communal agreement. I think that sort of over-view should be the case where the architecture is probably going to outlive any of the individuals, and be part of the inheritance of future generations. Communal common sense might be able to replace building codes.

actually we know that domes are inherintly strong after they are made then a volume enclosed by wood. If you have a person layout the initial rules (codes eeeek) then it is simple so manny feet x inches thick and how much rebar screening and use a simple tool to keep wall thickness equal. Pizza ovens of the Pompeii style have lasted 1,000's of years.

spark master (author)rapier12012-03-21

A friend of mine was asked to do an electrical side job. He agreed to look at the problem first as it was a not for profit that was struggling to give them a good idea of all the issues. 5 apartments he looked at (eventually) were all wired in the walls with ZIP CORD. That is our name for the inexpensive wire you might use to wire a light fixture. 16 guage twin fixture wire, whole apartments. 14 guage THHN wire (in appropriate conduit/cable/sheathing (romex, (not legal in nyc)), is rated at 15 amps you need 12 wire for 20 amps, and the switches and recepticles must also be rated same. All the breakers were 20 amps, including dedicated lines for small a/c units.

I guess a licensed insured and inspected job is needed for some things. How no one died is just shear dumb luck. They were too poor to really have big a/c units and so they lived. . Complete rewires for all the apartments cost a firtune plus what they paid the creepo who "did them a favor" then disappeared when there were issues.

The concept of glass bottles is to use whole bottles and embed them totally with the nipple end inside the structureGlass blocks can be set in concrete with no silicone and in a place like PR it is not an issue (I would think, but I R not beez a egineer. You have given me a pause to think about that though. I watched a few you tubes on how to make fake rocks Applied to your car hut it would make it blend even more then what you areasy have!

Thanks fer the great instructable.

rapier1 (author)Thinkenstein2012-03-20

It is possible that they could have a feel for what works. After all, there weren't that many building codes in ancient cities (though it might surprise you that some ancient cultures *did* have building codes and many medieval cities had codes as well). However. there was a pretty good set of ideas as to what did and didn't work with a surprising amount of math and engineering behind them. Builders and architects were really quite specialized at least in terms of larger structures. The poor generally didn't have access to them but if their houses and tenements fell down it really only affected poor people so the powers that be didn't mind that much. The growth of building codes in the US actually came out of late 19th and early 20th century reform and health movements. Their development is really an interesting looking at current thinking and concerns of the time. In any case, I won't deny that some of them may have become a little deranged and don't always take into account modern technology. For example, in my city you can't have a furnace exhaust within 3 feet of a window or door. Makes perfect sense when you think about the combustion products *but* with 95% furnaces that's not nearly as much of an issue as it used to be. When my last furnace went in they failed to keep this in mind but the city inspector made an exception. Which was awesome because I live in a brownstone and running the exhaust to the only other viable location would have sucked. That being said, if it wasn't HE that placement would have been a real problem.

spark master (author)rapier12012-03-20

A ent from my high school was a pro tennis player of some note. He was staying with friends at a huge place in the Hamptons. The gas dryer was not vented corrctly , He died. building code ignored or "we'llfix it later, when it is convienent" Heck if you do that and you kill your family well I feel bad but it is Darwinian.

Ancient builders of castles and Cathedrals learned through millenia of trial and error, and many many building collapses. Same goes for bridges , and most of th eearly bridge technology was built right here in the USA. Eiffel provided a big piece of how too and American RR engineers were told "build it" So they invented as they went. Same goes for tunnels and dams.

ya gotta love the history channel and nat geo and mil channel, so much to learn!

SANDBOX1 (author)2012-04-08

Codes, No Codes. I think you did an exceptional job and hope you continue your DIY projects and would love to see more of your work. The nice thing about DIY is you get to express yourself. GREAT JOB period.

Thinkenstein (author)SANDBOX12012-04-08

Thanks. This may be more than you asked for, but here's the complete list of my instructables to date:

jamstir (author)2012-03-22

I have to say pal, that,s pretty cool. Any building control you have to get around. lol.

When i seen the bamboo i thought this guy got to be Chinese, hahaha

jerryjaksha (author)2012-03-20

Nice garage.
It is amazing how much more versatile "concrete" is when you add some fiber to it.
There is a nice additive that you can add to concrete and mortar that waterproofs it internally, instead of adding coatings afterward.
It is used in making water tanks.It is called crystalline waterproofer.

If you can't find the stretchy nylon fishnet, an alternative is to add the chopped glass fibers to the mortar. You should be able to get them from a redimix concrete supplier. They come in 1 pound sacks.

Green Silver (author)2012-03-18

This would be a great idea for a kids play house, I guess you could even add a 2nd floor and window. A touch of bright paint would finish it off perfectly.

rapier1 (author)Green Silver2012-03-19

It would be even better if they did the structural analysis on something like this before hand. Things do have a tendency to fall down if you aren't paying attention. Not saying that Thinkenstein isn't but you can't expect that from everyone.

Thinkenstein (author)rapier12012-03-19

Well, simple domes may be easier to analyze than some of the more complex shapes I have done. Calculating the strength of egg crate shapes, or termite nest shapes would be a challenge for anyone, I'm sure, more than I would care to tackle.

The building departments anywhere tend to just say "no" to experiments that are over their heads. I live 1/10 mile from my nearest neighbors, so I doubt they would be affected by any structural failures here. Also, I have no insurance to affect anybody's premiums should anything fail. So, just give me room and you are probably OK.

I have been through hurricanes that destroyed other homes in the neighborhood without doing damage to mine. Given sledge hammers all around, I suspect I could raze most people's homes before they could raze mine. That, of course, is all untested speculation, and probably not the civilized way things are done these days.

Ideal would have the kids build their own playhouses, or schools, and by the time they graduate they are ready to build their own houses -- or termite nest cities.

Jobar007 (author)2012-03-19

How far apart are the rebar strands wired together? Any general rule to follow?

Thinkenstein (author)Jobar0072012-03-19

The rebars are probably about a foot apart. Because it is not a uniform square grid and there are diagonal members it is hard to calculate precisely. I would say the general rule is whatever experience shows works. I play it by feel, filling in any spaces that seem too large, perhaps more as an artist than as a scientist.

I have done work before in sort of a band shell area, with wider spacing that has a lot more belly sag between rebars than this does. It has been through hurricanes and is still standing with no problems.

narf7 (author)2012-03-18

The Flintstones! Love your garage and your individuality. Cheers for the instructable and for giving us all some great ideas

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Bio: I'm a refugee from Los Angeles, living in backwoods Puerto Rico for about 35 years now and loving it. I built my own home ... More »
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