back to article Concrete-jet 'printers' to build houses, Moonbases in hours

Most readers will be aware of so-called "3D printing" techniques, in which solid objects can be constructed automatically from computer models. Researchers in California intend to scale the process up radically, using "contour crafting" concrete extrusion to erect buildings in a matter of hours. "Instead of plastic, Contour …


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  1. dave lawless

    Edison did something similar

    The sweaty yank tried pouring cement houses and furniture!

    Didn't catch on though some are still around

  2. Janko Hrasko


    21st century's space swiss army knife aka A.C.Clarke's TMA-1's prehistoric cousin.


  3. Matthew Glubb

    Looks like someone's beaten you to the playmobil mock up

    Linked from their site:

  4. M

    WOW now I can tick replicators off my future list. Next up, flying cars. HANG ON, CAN WE GET THIS THING TO BUILD FLYING CARS?!?

  5. Anonymous Coward
    Anonymous Coward

    Self supporting floors

    I can't see how the machine can make floors since they aren't self supporting. They'll need some form of support from underneath as the floor is poured. Also I doubt it could make a two storey house in 24 hours - the bottom layers of concrete won't be strong enough to support all the concrete above it until it's set properly.

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  7. Anonymous Coward
    Thumb Up

    Cheaper houses

    Anything that drives down construction costs (including something that causes the 'traditional' building industry to lower prices in response to this competition) sounds like a great idea.

  8. Robert Govier


    The printer will be available from Staples for £500 in time for the Christmas market (with Wifi connectivity and one of those little screens for viewing photos), however it'll only come with a 25%, non-refillable toner, and you'll need at least 2 full toners to print a house, (costing 100 x the price of the printer).

  9. Pete Silver badge

    24 hours to errect the house?

    ... but it'll still take 5 years to get the planning permission

  10. Anonymous Coward

    Support its own weight...?

    "The equipment can happily create domes, vaults or any other shape that can ... support its own weight."

    Look, we did arches in primary school, and while the finished article can certainly support its own weight, I seem to recall that until the keystone is set in place, the arch requires external support.

    OK, so the Pantheon in Rome proves we can get a spheroid dome without a keystone, but even that required support during construction.

    I'm not calling these guys liars, but I think they need to provide a more thorough explanation of how this makes the improbable possible....

  11. JCL
    Paris Hilton


    Their website says it's environmentally friendly, but I'm sure old Kevin McCleod said that concrete is one of the least environmentally friendly way's of building a house. Who's right?

  12. Gianni Straniero

    Bad news for brickies

    The "credit-crunch" looks like putting large numbers of construction workers out of their jobs.

    Now this thing comes along and destroys, once and for all, their hopes of being sent to the Moon to wolf-whistle passing aliens and take 14 (earth) day-long teabreaks.

  13. Anonymous Coward
    Anonymous Coward

    @ Robert Govier

    In that case I'll take 8 of the buggers, which as far as my calculations go means that I'll get my entire house with foundations for about 4000 squid.

    Then dissasemble the house building printers and use their parts to build robots for the work commute.

    Housing crisis AND rushtraffic sorted in one go :D

  14. Charles

    Re: Support its own weight...?

    They have one advantage the old builders didn't: adhesion.

    Yes, an arch made of *blocks* or other loose members will need external structural support until it is complete, but the idea of this kind of project is to build it up little bit by little bit so that it builds up as at most two solid members which can potentially hold themselves up by the fact they're each one solid piece. A dome is even easier to achieve since the three-dimensional nature of the dome adds extra areas of adhesion and lateral support.

  15. Flocke Kroes Silver badge

    If you want to put a large building on the moon, hire Guy Fawkes

    Normal 3D printers lay down a layer of powder then melt the parts of the layer that will be part of the final object. The remaining powder is left in place as a support. Perhaps you could put down a layer of concrete power and only add water where the final structure should be. I would like to see the machine that picks up a house and shakes out all the concrete powder.

    While we are at it, what type of glue will set in a vacuum? This would have been a handy glue when the space shuttle had heat shield tiles on the front which fell off. Being able to go outside and stick on a few replacement tiles would have been very handy - except liquid glues evaporate in a vacuum. A 3D printer working with moon dust would only work inside an atmosphere. You could ship moon dust to earth, and print your building, but then you would have to put it back on the moon.

  16. Ben
    Thumb Up

    @AC more through explanation

    Have a look at the link Mr Glubb provided. It seems that the gantry is intended to pick up boards (lightweight, aluminimum probably) which look like they're to be layed on the freshly minted walls. From there it's pretty obvious that you just pour concrete over them to produce a floor. If that's done in layers, it become progressively self supporting so you really probably only need a tiny amount of supporting board. For curved shapes I imagine the idea is just to cut off any excess around the building exterior after it's dried?!?

    Really is one of those "Doh! That's so obvious, why didn't I think of it" ideas, isn't it! :)

  17. Eddie

    @Support it's own weight..

    You can build domes the Inuit way - a contracting spiral of material that sets as it is created.

  18. Miami Mike

    reinforcement needed!

    If you do this is seismic zones (California) or hurricane zones (Florida), you'll need steel rebars for reinforcement or these structures WILL fall down come the first quake/storm.

    Concrete by itself is quite strong in compression, but has no strength in tension, and doesn't bend at all. Just laying rebars between the printed layers won't do it - they need to run vertically as well, AND they get tied together.

    Interesting concept, though - but there are now materials and structures that are far more cost-effective than concrete. This system replaces a few thousand dollars worth of re-usable forms with a couple of million dollar's worth of high tech - which I note needs to have accurately placed track guides so when it moves back and forth the building is level . . .

    This whole thing smacks of using a howitzer to kill a mosquito.

    Moon structures can be built out of inflatable balloons sprayed with plastic foam, then concrete - and you won't need to move this huge, heavy contraption to the moon at all.

    Day late and a dollar short, sorry, guys.

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  20. Duncan Hothersall

    Fucking marvellous

    This is the technology that is going to build all those curvy shiny cities of the future with swishy shapes and tubes all over the place and people in silver suits and FLYING CARS!

  21. Anonymous Coward


    No, that's not it. Specifically, the grabbing bit that adds in prefabricated reinforcement is entirely optional.

    I eventually found the answer hidden in a PDF and it really is extremely clever -- and a true "why didn't I think of this!" moment.

    Rather than build the vault by steadily increasing the height of the walls and ceiling around it, they build it up by a series of inclined arches. Some of the weight of the arch can then be transferred downwards into the previous iteration, but this new arch meanwhile prevents its own apex collapsing.

    There's a diagram of the technique with the printer, and pictures of people using the technique in manually building adobe housing.

    A bit weird -- alien even -- but very very clever.

  22. Sampler

    House prices...

    So if you can build a nice new house for a fifth of the regular price how the hell am I supposed to sell my crap-hole for at least the mortgage value!

  23. Anonymous John

    Man, this refill cartridge weighs a ton

    Well, yes. But the ones that came with the printer, only weighed half a ton.

  24. Elmer Phud


    FFS Robert, please not in time for Christmas. It's bad enough for some parents to have Lego structures everywhere but let's try and keep quiet about the Sims add-on.

  25. TJ

    ..Missing the point?

    I think for marketing purposes they bill it as complete automation, however the reality would simply be there would still be men on site, either following behind the "printer" or working ahead of it or both covering all the bases. This is not an infomercial for some "set it and forget it" commercial device. And while building codes will play a big roll in its development, the fact Caterpillar is on board proves there is some economic viability. Setting this thing up would not be terribly difficult. The track would come on some railroad like prefabbed Track and just need to be level and straight, Something easily achievable. The Moon base and other uses are completely irrelevant to this stage of design anyway. We should encourage such engineering, not knock it down.

  26. Charles-A Rovira


    It needs to lay down rebar (Yeah, sure... Like that's ever gonna happen... :-)

    Otherwise its a very temporary solution (that's when the concrete doesn't sag and crack from its own weight.)

    Concrete by itself is not a very good building material.

  27. RW
    Thumb Up

    Re: Support its own weight...

    There's a technique for building arches, domes, etc that requires no centering. Two famous examples of this are the enormous adobe banqueting hall (ruins thereof) at Ctesiphon, a relic of the Sassanian empire iirc, and a huge immigrant reception hall on Ellis Island in New York with quite shallowly arched ceilings.

    Scientific American had an article on this 10 or 20 years ago that's worth looking up if you adore novel construction techniques. I can't say just *how* this technique could be used the the HP HouseJet, but it demonstrates that "centering is necessary" is a falsehood.

    The dome of the Duomo in Florence, erected under the supervision of Brunelleschi, exemplifies another method of erecting domes without centering.

  28. Steve

    still slow

    > erect a 2,000-square-foot, two storey house in 24 hours

    So still slower than Spanish builders throwing up hotels, then?

  29. ian

    Why send portland cement + water + gravel + sand to moon?

    Current construction methods with styrofoam forms (heavy industrial stuff, not insulated cup variety), and foamed concrete would likely work in a vacuum, and be much lighter than the stuff delivered by lads with wheelbarrows.

    Further, the Moon's lower gravity would allow for weaker materials to be self-supporting. However, would a shirt-sleeve environment (5psi atmosphere?) inside blow out the walls?

    Still, a nice little lunar summer place would cost billions.

  30. Richard Cartledge

    I''' wait for the laser printer version

    Can't be doing with blocked nozzles, wasting concrete doing head cleans, doing nozzle checks and aligning heads to find that the concrete cartridge needs replacing again.

  31. Tom Silver badge

    Two questions

    1) Where do you pour the tea?

    2) Is there a Polish version coming out soon that works twice as fast, and doesn't disappear on other jobs?

  32. Jeff Davies
    Thumb Up

    There are numerous ways to construct arches

    1. make a small supporting pillar system that is easily dislodged when the full arch is up.

    2. just make a solid wall, and use a diamond tipped teeth chainsaw to make the doorways and windows.

    Also by using a lot of lime in the concrete, it can set in 10 minutes. (strong enough to walk on).

  33. Anonymous Coward

    Same, but in sugar...

    No-one's mentioned

  34. lee harvey osmond


    ... all those comments, and only once has 'rebar' been mentioned. Structural concrete does get a bit more durable if you add steel reinforcing bars to it. Well, the structure becomes more durable, while the concrete becomes less durable. Although somebody did mention the Pantheon, proof that you can make something really big without rebar and yet it will not fall down. [Although those pesky Romans did cheat as I recall by using extra-lightweight pumice as the aggregate in the top bits.]

    But ... somebody suggested printing concrete Levvies? What's going on there? Does somebody mean to prefab Hebrew priests to officiate in some lunar Pantheon, or are they going to ship in the priests and use the inkjet thing to make them denim trousers out of concrete on-site?

    Personally, I think some of the commercial possibilities of terrestrial concrete inkjet printing have been overlooked -- cheaper than HP, with stronger more vibrant monochrome etc etc etc.

  35. Rob Crawford

    Regarding Edison

    I wonder who that thieving bugger stole the idea from, as almost all his major credits turned out to belong to other people

  36. Andrew Tyler


    So long as it comes with a sound-system that plays Raymond Scott's "Powerhouse," while it works, I'm totally sold.

  37. Chris G

    Rebar may not be necessary

    There is a method using high tensile metal needles in the mix that produces a strong concrete with a degree of flex in it, similar concept to fibre glass and yes concrete does flex just not very far. In that respect it is a little like glass, when it is pushed past its max for flex it falls apart.

    This machine looks a s though it is an architect's dream, to get rid of the nasty messy builders. Just as most builders would like to get rid of the airy fairy soapy architects.

    If this invention takes off it will cause economic collapse as the construction industry is probably the biggest single employer. Although there may be a lot of work in bigger cement factories.

    Concrete is very un-green, it takes a lot of heat ( big carbon footprint ) to make cement out of chalky rocks. Then roughly for every kilo of cement you need five kilos of sand and aggregate plus lots of water and a lot of energy to mix it and to move all the ingredients around. Oh and the rock and the sand has to come from somewhere, like scenery!

  38. Wokstation

    I'm thinking this technology...

    ...may find itself legislated against for terrestrial use. Many low-income and/or low-skilled people would be put out of work by this machine.

  39. Adrian Esdaile

    Getting closer....

    Yep, you need reinforcing steel for concrete to work. Concrete only works in compression, so some very fancy domes are possible - think La Sagrada in Barcelona, or the Pantheon in Rome - both are self-supporting concrete without tensile fibers (ie, steel reinforcing) although I think the Romans used straw & flax as a tensile elements in mortar. So you could do decent structures without reo. As for earthquake proof - the structure would be monocoque and probably less susceptable to fracture.

    I can think of a brilliant way to get steel reinforcing into a rapid-fab process like this though - knitting!

    Literally knitting - a net of needles could knit steel fibre (or glass / carbon / boron / kevlar / hemp / bone / monofilament diamond nanotubes) straight into the matrix as it is laid. It would be *way* stronger than standard straight reo, in the same way a cable is stronger than seperate fibres - friction, compression and shear forces are introduced through the weave, so the fibre is working more efficently.

    I think it's bloody brilliant, and I can't wait.

    Back to telling moronic formworkers how to set out parabolic-curved formwork!

    A Real Architect

  40. Charles Manning

    Yes but where are the drivers?

    No Vista drivers yet.

    This is really nothing more than a version of continuous profile concreting, of the sort used to make curbs etc, just done in 3d so as to build higher structures.

  41. Phillip Brown


  42. Anonymous Coward
    Anonymous Coward

    Concrete boats?

    Doesn't sound like a clever idea at all to me.

  43. Duncan Hare

    I fear a few lumps in this mixture

    And pray, what kind of nozzle spits out a widely variable size of "drops"? Or is the a nozzle for each particle size (which makes "mixing" the concrete interesting.

    Concert is an aggregate, not a uniform emulsion like ink, and, how do they print the reinforcing? This I must see!

  44. Ian Lowe
    Thumb Up

    Concrete Boats - been there, done that..

    Ferrocement boats built using a concrete skin on steel mesh have been in use for over a hundred years - and last for a long, long time.

  45. TeeCee Gold badge


    Obviously the *real* purpose of these machines is to subdue large groups of unruly fleshies by covering them with quicksetting concrete.

    I, for one, welcome our house-extruding overlords.

  46. Steven Jones

    @AC - Concrete Boats

    There's a long history of concrete boats and ships going back to a French patent in 1855. They are normallyt called ferro-cement boats, and as the name implies, are actually built of cement on a ferrous (steel) mesh. There's also talk of submarines being deigned in the material (that I suspect is not such a good idea).

    Before the days of fibreglass it was a way of achieving a moulded shape. Enthusiasts still build the things of various types - sailing yachts, house boats; all sorts. The weight is not so much of an issue - many boats require ballasting anyway; it's just a matter of keeping the base a bit thicker.

    Having said all that, I'm not sure building a boat of concrete without reinforcing is such a good idea.

  47. Dan


    Very clever, but it sounds like either there will still be quite a bit of labour involved, or the creators have been played too much Command and Conquer "Building Complete! Building Complete!"

  48. Trygve

    Reinforcement - Does no-one ever read before commenting???

    Look at the PDF AC linked to above. A proposed method for "Robotic modular imbedding of steel mesh reinforcement into each layer" is described and illustrated at the bottom of page 4, and wire reinforcement at the top of page 6.

    They may not ever get their uber-robo-brickie to work reliably, but the bulgy-bonced boffins are way ahead of you amateurs.

  49. Anonymous Coward

    @Support its own weight...?

    When was the last time you saw an igloo formwork?

    An igloo is a self supportting spiral dome. Arches are also possible with adequate cantilever support (ie tied into a wall) but this is what is meant by 'self supportting' as opposed to a regular dome/arch.

    Additionally there is no reason why formwork cannot be used with this technique, it just needs manpower to place and remove, the formwork would be horizontal surfaces only as no side support is needed, so is far less cumbersome than that in use today.

    for those struggleing with the concept, think clay not concrete there is no pooring, this is an extruded paste like clay (or adobe!) which is laid in stripes, as mixing can be performed by the machine on demand it can be very quick setting, so very rapid construction can be used. (hardening/curing will take longer)

  50. gareth

    @AC RE: concrete boats

    why but steel boats sounds like a clever idea.

    the material a boat is made out off has little baring on its ability to float. That is dependant on its ability to displace a larger mass of water than its mass which a design issue. as long as that is correct for the material used you can build a boat out of pretty much anything that can be made water tight

  51. Tim

    @ AC- Concrete Boats

    It's been done of the many delights of Canvey Island

    that landing page is so freaky.

  52. Anonymous Coward

    Rebar is now optional...

    Recent developements have seen fiberous materials mixed into concrete in such a way to massivly increase its tensile strength. Shotcrete has used wavey metal strips (like staples) for many years, now newer materials such as kevlar are being used, yes its more expensive, but its cheaper than many many man hours.

  53. Anonymous Coward

    Glue and vaccuum's

    While we are at it, what type of glue will set in a vacuum? This would have been a handy glue when the space shuttle had heat shield tiles on the front which fell off. Being able to go outside and stick on a few replacement tiles would have been very handy - except liquid glues evaporate in a vacuum

    Loctite (r) do anaerobic glues, superglue(r) for instance sets when the parts are pressed together and the air expelled

  54. John

    economic collapse?

    yeah, like the factories of the industrial revolution. and the tractors and combine harvesters of the farming revolution.

  55. Fenton

    Green Concrete

    I though I saw an article a few years back about green concrete that actually absorbs CO2 and in the process makes it stronger.

    Yes it takes more CO2 to make but over the lifetime of the building it will actually absorb about 2x the XC02 used to make it.

  56. David Hayes

    Test Page

    So we'll print a test page in Windows just to make sure it works on the moon. Some nice advertising on the moon for M$ then!

    Mine's the one with the really long telescope to read the test page on the moon!

  57. Stephen Gray

    @ TeeCee

    LOL!!! You cant go wrong with a little Kenny Brockelstein

  58. Anonymous Coward
    Anonymous Coward

    concrete boats and harbours

    Knew a chap (with no maritime skills) who bought a concrete boat.

    Went off sailing in it and didn't realise it would take a while to slow down at the harbour. Apparently there was a lot of shouting, a huge crunch and he was never allowed back in that harbour (after it had been rebuilt). The boat suffered minimal damage.

  59. Big_Boomer Silver badge
    Thumb Up

    One off houses?

    Waste of money to build a single house this way.

    The reason CAT are into this is mass market.

    Imagine you arrive at your virgin site, lay 10 rows of tracks, fit the printer to the first row and press start.

    Once it's finished the 30th house on that row, you move it row 2 and press start,.... etc.

    In the meantime you just have the keep the machine topped up with concrete and rebar and stuff.

    As for people who live in earthquake zones, well more fool you. :-)

    Modern concretes can use shredded waste instead of rock and are better for it. Build your house using landfill.

  60. Steven Jones

    @AC - Glue and vaccuum's

    anaerobic really means "without oxygen" not "without air" (sometimes it will be loosely mean the latter, but that's not really accurate).

    The real problem with the vacuum is the rapid evaporation of liquids. Nothing can remain liquid in a vacuum. For a glue to work in vacuum it would have to be spreadable and it's a bit difficult to see how that would be done, although I suppose if it was something with very low volatility then it might be possible.

    That's a very different thing to glues setting in a vacuum - that's perfectly possible.

  61. Simon Millard


    And when it runs out of concrete, it'll be cheaper to buy a new printer

  62. joe K
    Dead Vulture


    @Fenton : I think you might be referring to limecrete, which is a concrete equivalent made from lime (CaO) instead of the limestone (CaCO3) in concrete. As its set the lime absorbs CO2 from the atmosphere and slowly turns into limestone (CaO+CO2=CaCO3). However, its notoriously difficult to machine,is more brittle and takes considerably longer to set.

    My problem is with this whole green fanaticism. The planet is living and self regulating. Using one naturally occuring material instead of another is not going to prevent an impending doom from happening. Adopting limecrete to save the planet is no different to a 1 million strong colony of ants in an anthill in equatorial africa deciding to reduce their daily leaf harvest by 12% in a bid to cut their carbon footprint.

  63. Anonymous Coward
    Anonymous Coward

    Best ever subhead! Kudos...

    What the title said.

  64. Lukin Brewer

    Roger Dean will love this!

    Roger Dean is best known for creating record covers, usually depicting unearthly landscapes and buildings, plus the odd bit of set design. However, he actually trained and qualified as an architect and interior designer before he got sidetracked into cover design. A lot of the buildings that he painted were conceived as practical builds as well. He has tried (and in a few cases, succeeded) to get the buildings constructed. This technology would presumably make it as quick and cost effective as any other structure.

  65. Vlad

    I dread the helpdesk calls that this one might generate!

    User: Hello, is that the Helpdesk? I've got a problem with my concrete-jet printer. I've tried printing the Concert Hall job five times but it keeps going wrong! Your engineer might need to bring a sledge hammer along with them.

  66. Waldo

    WELL Well well

    ..... I 've heard of shitting bricks but....:-P

  67. Paul Stephenson


    presumably if this where used on houses it would be cladded in soemthing, cause generally speaking concrete looks like sh!t. most 1950's buildings anyone? :)

  68. truenorthern

    efficient already

    I hope they can make this work, they have a long ways to go to make what works an inch wide in the lab work on a typical building site.

    and I have sure seen a lot of these types of efforts. Someone basically outside the construction industry comes along and determines that all construction is inefficient and that they can do it 10 times faster, 10 times cheaper, and now more environmentally friendly.

    Well, I have news for you construction professional operate extremely efficiently and at least in residential housing marginally are razor thin with very high competition.

    one more thing, softwood lumber is a renewable resource. Nearly all the lumber in Canada/US comes from plantations. The whole process is self sustaining, we have not been harvesting more than is sustainable for years,...

  69. Richard Clayton

    Ooops... sent it to the wrong printer

    Anyone who works in an office knows the problem of sending stuff to the wrong printer.

    On discovery of this it is usually only a matter of walking to the actual printer you sent it to to find out that it is on the wrong size paper or is black and white instead of colour

    Imagine the horrors of looking out the office window and seeing your email printed out in glorious concrete several feet high!

    Including the signature line "Please consider the environment before printing this email"

    I'll get my concrete overcoat...

  70. Adam Foxton
    Thumb Up


    You mean like 3D printers? Like the ones that have been out for years and are even mentioned in the article?

    Apologies for the sarcasm.

    And yeah, they're awesome! Wish I had one at home...

  71. rhidian

    the pdf is good

    As AC said above.

    Quite a bit about the process in there, including the reinforcements methods and domes etc. Worth a read :)

    I do like the idea of printing to the wrong printer or print jobs getting stuck in the Q ;p

    Wasn't there a usb device that would fabricate you a mug or some such thing? What was that called?

  72. Acme Fixer

    @ dave lawless

    Not according to The History Detectives. Edison wast stuck with the equipment that could make cement, so having a load of lemons, he tried to make lemonade. He said he was going to build the cement houses, and got patents on the concept of a concrete house poured into a mold. But his plans fell through, so it didn't happen. Instead, a guy named Ingersoll built some concrete houses in Union, New Jersey using Edison's techniques (the street they're on is named Ingersoll), but they were NOT built by Edison.

    See and The History Detectives.

    "Raymond: Well Edison’s attitude was “I didn’t fail. I just found ten thousand ways that didn’t work.” So after all these media attention, Edison decided to cut his losses and get out.

    Gwen: But that’s a disparity, because Antonio’s house was built in 1917, which is a number of years after this.

    Raymond: That’s right. Well, it turns out that Edison never did build a concrete house."

  73. Tim
    Thumb Up

    You can print floors, you just need to kinds of "ink"...

    ...normal 3d printers print with two materials and one of those materials is blasted away with a water jet to reveal the finished product. So if you want to build a hollow cube, its a simple matter of printing with concrete and um, sand I suppose, then removing the sand when you're done.

  74. William Lane


    Search Stereolithography, this is the same thing as had been around for a while now, but was used in smaller scale for rapid prototyping. This is a great way to use this technology. I wonder what the machine/structure cost, and the easy of transportation/movement.

  75. Brian
    Thumb Up

    RE: Roger Dean will love this

    I've had the good fortune to get to know Roger over the past few years at a USA Progressive Rock Festival (NEARFest) and he has shown me many designs of modular housing, etc that has an incredibly homey feel and beautiful design.

    I love his work, and he should be as well known for his archetecture as his artwork!

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