3D printed house

Attached is a link to a video showing 3D printed houses, a printer can do all the perimeter walls of house in just one day, some done in a honeycomb style and the voids filled with Rice Hulls for insulation.

Watch robots build houses at incredible speed. 3D printing meets AI. - YouTube

 

For as much as I think this is a great idea and speeds up the building process a great deal I'm not so sure it is suitable for the Philippines? any house here that is 75% concrete will always have the problem of heating up during the day and give off a slow release of that heat at night, even when fully shaded it will still absorb the ambient temperature during the day, which is 5/6 degrees more than when the sun goes down.
Back in Scotland during the late 60's early 70's, they had a great idea, Night Storage Heaters, these were large metal cabinets filled with concrete, through this concrete there was passed a heating element, during the night Electric power was supplied at a cheaper price to anyone with this heating system, so between 8pm until 6am, these heaters were working overtime, giving off some of the heat then, but the idea was to store the heat in the concrete to make it available during the day, on a very cold winters day your stored heat would only last a few hours.

When I first looked into building a house here, I immediately rejected the idea of a CHB house even AVG insulated sandwich panels.
They are just Night Storage Heaters in reverse so I started to look at alternatives, Bamboo House done in the traditional way, not as they are done now? they need a 60 degree pitch to the roof to shed the water and stop the grass material from rotting, how well can it be treated against Termites and who can you trust to do this correctly? then there is Coconut wood and around 33% from the bottom of the tree is quite hard, this Termites do not like but they will eat if no softer wood is available, it can be treated but how long will the treatment be effective in the long term there is a chance it may not be after say 10/15yrs? I think the better option is a Steel Stud framed house clad with Hardiflex a thin Cement board, the cavity in the stud framing can be filled with insulation, this can be expensive when you can get it here as it is little used, but then we have rice hulls, meets all the requirement of most insulation material, Termites cannot digest it very well it is fireproof to a degree, this can be improved by adding Borax and Boric Acid to it, a couple of good men can build the frames, erect them on a prepared foundation plus fit the cladding material, in 2/3 weeks, a CHB house would take 4 times that long with 6 men when you include the rendering, cutting channels in the walls for electrics, finishing the sides to the doors and windows.

Which type of house will last the longest?
I have no doubts in my mind that 99% of the CHB type will fail long before the Steel stud frame type, the reason for this is; the highly porous hollow block which contains steel rebar has not been rendered with waterproof mortar from the foundation to well above grade, mostly the render starts from just under the soil grade to leave the steel under that exposed to moisture, also the trend here is to use the Premier Portland Cement, again that can also cause problems and should never be used below ground and especially in Septic tanks, blended Pozzolan is by far the better choice and tanks should be rendered both sides for the above reasons.

IMHO; CHB houses are a well Fcuked up idea, especially here in the Philippines where for the most part the native workers have very little skill and do not know how things should be done, after all most have no formal training, even above them the Architects have little if any building and engineering skills?
Don't trust most of the Foreign Builders here to know what its about either, they are the ones building CHB houses with no render under grade, using Portland and not blended cements and telling the customer they are getting the best.

Sorry for being so long winded, I really wanted to give warning to any newbie that may consider building a house here, trust no one, do your research and self manage the build yourself, that means being on site 8hrs a day, when the Cats away the Mice will play.

 

Termites like soft moist wood. There are many locations on earth that have learned how to deal with termites. In the US most homes are wood framed with a relatively soft wood. (fir or pine) Older homes do not have any insulation and the Sole Plate/Bottom Plate was not treated. This is the wood that laid on the concrete where it would remain relatively moist. Modern construction uses treated lumber for the bottom plate. The older homes would only require termite treatment every 10 years (often much longer).

You are correct that the lower third of the coconut palm "stem" is much harder. Furthermore the outer portion of the stem is harder than the inner portion. The coconut palm "stem" is different than the wood you are used to in your home country because the coconut palm is *not* a tree.

Trees have the harder stronger wood in the center. This is called the heart wood. The tree perimeter is the softer wood that is used to wick water up the trunk. Whereas coconut palm is the reverse of this. Coconut palms have the harder stronger wood around the perimeter. The center is used to wick water up the stem.

If you had read the links I provided previously you would know that a wood framed wall has double the insulating capacity of a steel framed wall. This is because the steel framing is a very high conductor of heat.

Based on research I have done, the best solution would be to build a coco wood framed home with wood fiber concrete siding.

1) Build up the perimeter of the foundation with a good quality 6 to 12 inch high concrete curb. This will get the wood bottom plate up from the rest of the slab, moist ground and subterranean termites. (Do not use CHB for this.) During inspections you will be able to see the subterranean termite tubes up the side of the foundation.

1) Use treated or the harder coco wood or a termite resistant specie for the bottom plate.

2) Insulate with a borax/boric acid treated insulation. This will encapsulate the wood framing and stop termites from getting to it.

3) Use a cement board siding. There are many types. some have a wood grain imprinted on them. Wood Wool Cement Board is also a choice.

Resistance of Wood Wool Cement Board to the Attack of Philippine Termite
https://www.mdpi.com/2075-4450/3/1/18

THE EVIDENCE:

There are many wood framed structures in the area that have been standing for a very long time. (100 years plus) Up near the sugar cane plant in Bais there are old colonial style homes. A closer example would be the Break Time restro bar in Sibulan. Go check it out.

https://www.tripadvisor.com.ph/Rest...an_Negros_Oriental_Negros_Island_Visayas.html

 

I have no reason to disbelieve any of what you say, my wife's parents live in a Cocowood house for 40yrs and still there, but it is riddled with Termites, (very likely not treated) also I have seen many very old wooden building here in the Philippines likely they are made with a hardwood such as Nara? but I will be using steel for my project much easier to work with than warped wood (although most Coco Lumber is fairly stable) I can only hope the Rice hulls will give me all I need for insulation? for sure anything must better than a CHB house, as I said a night storage heater in reverse.

 

Something I have not mentioned before is; my objective is to build a small house for my wife and child, something that she can afford to live in after I am gone, which means no AC needed and low maintenance, it will have no gutters, but the best available plastic roof Imac roofing, I'm hoping this will outlast a steel roof, I am kind of wallowing in the dark a bit although I have done many different projects in my life I have never taken on a house build, however I have done lots of research these past few years and just started the work some few months ago, using only 3 workers, so at most I only have 3 problems in one day also I am there 8 till 5 every day 6 days a week, I'm not a slave driver by any means and sometimes my workers take a little advantage of me and take longer breaks than they should, but for the most part they are good people, honest as they come, I've yet to have a tool go missing and when they do break something (often) they usually tell me, are they good at their Job? sadly the answer to that is a big NO, the 30yrs experience they have between them counts for nothing. Attached is a picture of a house that I am trying to copy after a fashion?

 

I get your analogy to a concrete house re the 'storage of heat' but, actually, I hated storage heaters in the UK. The ones I know had bricks inside - the problem was that on a cold day the stored heat would run out quickly and on a hot day they would be giving out heat you did not want!

One building issue (other than good insulation) is why there is not a vent at the very top of houses to allow heat out - I saw a photo of a house that had something looking like a vent but not sure if it was. I advised my sister-in-law to have double glazing when she was replacing her old windows - for heat and noise insulation. The builders put in two panes of glass but they were not sealed units with argon (or whatever these use these days) in between. She says they do cut down some noise but the diminution of 'the greenhouse effect' is not really measurable. I always keep my curtains closed (they are thick ones) as I figure the extra lighting (LED) I use may compensate for keeping the house cooler and thus reducing aircon use.

Because concrete walls absorb heat, is there a way of having an outer skin of something else, with insulation in the gap, such that the heat never really gets to the concrete?

And shouldn't roofs here be white?

 

I am intrigued by this - what is a coconut palm if not a tree? Do you mean it has a difference from other trees in where the harder wood is located?

 

Good point. Roofs here have inadequate ventilation. Maybe an effort to keep critters and heavy rain out.

In many cases a whole house fan is cost effective in reducing the heat absorbed by the home. Typically they are used intermittently to pull cool air in from the lower windows and eject it out the roof. They are used in the evening to exhaust the heat built up during the day. They can also be used in the early morning to pre-cool the home. Just like your brick heat storage, the mass of the home can be used as a thermal flywheel. The house can be chilled down during the pre-dawn hours by pulling in air and ejecting it out through the roof. This way the entire structure gets ventilated and cooled down. Starting at a lower temperature it will take longer to heat up so there will be more hours in the day that are comfortable without A/C.

It is best to use glass with a low-e (low-emissivity) coating. This blocks the non-visible wavelengths of light. This way the greenhouse effect is reduced by reducing the heat gained from light wave lengths that you do not see. Your home has the same illumination from the window with much less heat gain.
https://www.guardianglass.com/ap/en/tools-and-resources/resources/faqs/commercial/what-is-low-e

Another skin costs money. More cost effective to use a minimum number of skins and insulation to save costs.

This depends on the type of roof.
The nipa roofs work very well at not heating up. The outer individual strands have air flowing around them that takes away the suns heat before transmitting it into the rest of the roof material. Any other solid roof will conduct the heat into the home.

I am surprised that people do not use a thin layer of sac sac on top of something else (tin or plastic).

White shows dirt more easily, so it will look grubby.

 

The coconut palm has the harder stronger wood around the perimeter.
The coconut palm belongs to the grass family like bamboo.

Botanically, the coconut palm is not a tree since there is no bark, no branches, or secondary growth. A coconut palm is a woody perennial monocotyledon with the trunk being the stem.
https://www.loc.gov/everyday-mysteries/item/is-a-coconut-a-fruit-nut-or-seed/

There is some drama about this:
https://www.bbc.com/news/world-asia-india-35417168

 

Double glazing never did have any inert gas between the panes, although most people think that including myself till a Glazier friend explained to me, it is just air, the spacer bar between the panes has these desiccator crystals in the hollow square tube to take out the moisture. yes you can retro fit insulation material outside the concrete walls that is what they did to the block of flats in London that caught fire some years ago, just make sure it is fireproof, my friend built a house recently using CHB it is 1.5 stories high, kind of open plan, it has a flat pitched roof and on the high side of the roof he has a couple of extra small rooms and also a hall between a bit like an atrium or gallery, so he has windows at the extreme height of the house and that definitely vents out the heat, you are also correct about the colour of the roof, the picture was of a house of a design I like, but my roof will be Plastic in a light cream colour.
I know it should be Skipjack that answers the question about the Coconut tree, he does know his stuff, but I do know a little about it and even made some furniture of sorts from it, firstly it seems to be quite stable the woodcutters cut fairly straight pieces from the tree and they tend to stay that way if stored correctly, in some ways the good stuff behaves like a very hard wood it will not accept a screw unless you drill a pilot hole, often that screw will never come out again it grips it so well, put it through an electric Planer and mostly you only get dust and not shavings, takes a bit more work to get a good finish on it but that is achievable, I even made a pair of Drumsticks for a Drummer I know here, he said they looked so fine he never wanted to use them?