[myuncle (OP)]

Soundproofing can be easier maybe in the near future. No more blankets, carpets, thick panels on the walls, ceiling, floor. 3D printed houses don't leave gaps, but if they leave just a few mm of space between the wall, ceiling, floor, it could be vacuum pump easily later, if the tenant needs to.

[Bored chemist]

it could be vacuum pump easily later, if the tenant needs to.

What?
A vacuum chamber has to stand up to air pressure. Something like 10 tons per square metre.
Good luck with that.

[Origin]

Soundproofing can be easier maybe in the near future. No more blankets, carpets, thick panels on the walls, ceiling, floor. 3D printed houses don't leave gaps, but if they leave just a few mm of space between the wall, ceiling, floor, it could be vacuum pump easily later, if the tenant needs to.

All we need is a humongous 3D printer that is big enough that heavy equipment can drive into it to remove the house.  I'm thinking this is not going to be something happening anytime soon.

[chiralSPO]

It has already started happening:
https://www.cnn.com/style/article/3d-printed-house-scli-intl/index.html

[CliffordK]

A bit of a word jumble in the OP's post. 
Vacuum Pump or Vacuum Cleaner? 

Sound deadening tends to be the use of certain materials such as rubbers, or porous materials such as foam.  A 3-D printer could potentially print a porous material, or augment the printing by using self-expanding foam.

[myuncle (OP)]

A bit of a word jumble in the OP's post. 
Vacuum Pump or Vacuum Cleaner? 

Sound deadening tends to be the use of certain materials such as rubbers, or porous materials such as foam.  A 3-D printer could potentially print a porous material, or augment the printing by using self-expanding foam.

I mean any piston pump used for vacuum containers. If the concrete doesn't crack, it can be an easy task for the 3d printer to leave just a tiny gap.

[Bored chemist]

What do you plan to use the pump for?

[CliffordK]

What do you plan to use the pump for?

Putting a house under high vacuum might be an excellent way to kill off fleas, lice, bed bugs, and other pest species.

But, it could also damage anything with a closed foam cushion, as well as seals on canned goods. 

Houses typically aren't 100% airtight.  It might be a goal to make the house airtight, but that might contribute to carbon dioxide buildup, as well as trapping noxious smells.  Perhaps even water vapor buildup.

[Bored chemist]

It is unclear what the OP is talking about.

If you were to build (by 3d printing or not) a house with hollows in the walls (A bit like sealed double glazing units)and floors an then evacuate the air from the gaps then no sound would go through the vacuum.

However, the forces on the surfaces of these thin flat vacuum chambers would be enormous.
And round the edges there would have to be enough solid material to hold the gap open.
So it would need to be rigid, and firmly fixed to the "panes" on either side.
And that,of course, would transmit sound really well.

[Janus]

One method that can be used to reduce sound traveling through a wall is the staggered stud.
The wall is made a little thicker than your studs, with the studs placed half as far apart. Every other stud is staggered like this:


Soundproof.png (2.19 kB . 411x101 - viewed 6989 times)

This way, the the sheet-rock on either side of the wall aren't affixed to the same studs, and is more difficult for sound to pass through.  This can be augmented by putting some type of sound proofing in the walls.

[Bored chemist]

One method that can be used to reduce sound traveling through a wall is the staggered stud.
The wall is made a little thicker than your studs, with the studs placed half as far apart. Every other stud is staggered like this:


Soundproof.png (2.19 kB . 411x101 - viewed 6989 times)

This way, the the sheet-rock on either side of the wall aren't affixed to the same studs, and is more difficult for sound to pass through.  This can be augmented by putting some type of sound proofing in the walls.

Now imagine covering it with a thin layer of plastic sheeting and sucking the air out.
:-)

[CliffordK]

There are two aspects of sound transmission, and different needs depending on the application.

Through wall sound (toilet flushes, TV in next room, etc), and within room sound.  (restaurants, theaters, etc).

The vacuum in the middle of walls would help with the through wall sound propagation, but a hard surface will still reflect sound.

[Eternal Student]

    The OP idea of evacuating a small space between walls of each room seems like quite a good one to me.  Previous replies have already mentioned the obvious problems, benefits and practical requirements.  It seems that a partial vacuum would be more realistic since it will reduce the forces on the cavity walls.  No-one has mentioned that the OP idea would also help with heat insulation in addition to sound insulation.

    A hybrid of methods to help with sound insulation is probably going to be more realistic.  Janus has already mentioned one practical idea - the use of staggered studs.  The 3-D printer could also be programmed to produce sound-cancelling patterns on the walls.  Typically small pyramid shapes are placed on the wall under the principle that sound reflects off these surfaces and the superposition of waves will be destructive, annihilating the sound.  If you don't want to look at walls with this sort of pattern then you can put the pattern on the inside surface of the cavity walls.

   I expect there are many things that could easily be adjusted and improved for a 3D printed house but I suppose the short term concerns are just building quickly and cheaply.  Any extra material (to increase strength of the walls or create patterns) would only increase cost and production time.  There also seems to be a limited serviceable lifetime for such houses and a need to minimize any repairs or regular maintenance.  A vacuum cavity wall is very likely to develop a leak and require maintenance and this may defy the original purpose and design brief for this new technology.

[wolfekeeper]

I strong suspect that filling such a gap with sand or gravel rather than pumping it down would be a more practical technique; heavy materials reflect sound pretty well. The other issue is reflections within the room, do you really want a room extremely echoey?

[Bored chemist]

The OP idea of evacuating a small space between walls of each room seems like quite a good one to me. 

How do you make them strong enough to stand the thousands of tons of force that the atmosphere would exert on the walls of a typical house?

It seems that a partial vacuum would be more realistic since it will reduce the forces on the cavity walls. 

Do you mean partial vacuum that's less than nine tenths of an atmosphere, in which case the forces on the walls are still unmanageable, or do you mean more than a tenth of an atmosphere where the sound attenuation would be practically no better than simply having an air filled space.

[Bored chemist]

  Typically small pyramid shapes are placed on the wall

No.
Typically large pyramids are fixed to the walls.
You would lose a foot or two on each wall.
And they need to be something soft to absorb sound.

[Eternal Student]

Hi Bored Chemist, I hope you are well.

I'm not disputing what you have said, it looks sensible to me.

The practical problems (such as extreme force on the walls) has been discussed before.  It is recognised that this problem is huge.  It's probably not a realistic idea.  The cavity wall can stay but some other "fluff" would be injected into it.  You could print sound-cancelling wedges on walls, just as you could print tables and chairs but you would probably want to add some other materials onto the outside of them.  It probably uses too much material and defies the original brief, this was also previously discussed.

None-the-less, I'm not going to alter my opinion that the OP idea was a good one.  It demonstrates a good understanding of scientific principles and it's not an idea I would have thought of.

[myuncle (OP)]

None-the-less, I'm not going to alter my opinion that the OP idea was a good one.  It demonstrates a good understanding of scientific principles and it's not an idea I would have thought of.

Many thanks, don't alter your opinion  , it's extremely rare to see someone praising me in a scientific forum, actually this is the first time, hehe. Not many people post in a science forum, I'd love to see more posters, like for cooking, painting, sport, art forums, but it's difficult. I am a layman here.

[evan_au]

NASA had a competition to produce a 3D-printed house that could be used on Mars.
- Outside air pressure is 1% of Earth normal, so not much sound from outside
- Inside air pressure could be 20% of Earth normal, so reduced sound inside
- Thick, rounded walls to withstand the pressure differential

See: