I am myself unsure as to how well this would work.

Currently, rock is quarried, modified, shaped and transported distances to be made into buildings in the form of bricks, concrete, mortar and sometimes actual stone such as granite or marble. This renders it vulnerable to damage. Instead, moulds made from some kind of refactory material such as tantalum carbide could be assembled on-site and filled with molten rock in order to form solid buildings of specific rocks, including window frames, ceilings, walls, floors, plumbing, cavity walls, conduits for wiring, doorways and so forth, in whatever shape desired. I have previously mentioned "limehouses", and I stick by that idea, but it occurs to me that less water-soluble compounds such as silica are amenable to this form of construction.

This is the bit I'm not sure about: I suspect big, monolithic buildings would be more vulnerable to damage by subsidence and other natural hazards than houses made of brick, but I'm not sure. If not, and they are in fact more durable, the prodigious energy use they embody would pay for itself with their relative immunity to damage and low maintenance needs.
-- nineteenthly, Jan 03 2023

Carved stone house https://www.coolsta...house-retreat/17716
I'm struggling to find igneous rock cave houses, this one is sandstone [pocmloc, Jan 03 2023]

Basalt Rebar https://basalt-rebar.com/
[Voice, Jan 04 2023]

Using the available rock on site is certainly attractive. So about 1000 degrees C to melt various rock and pour into forms. Might utilize a future fusion power supply for this.
-- whatrock, Jan 03 2023


Are ice palaces currently built like this? That could provide a parallel since they rely on phase change to set the material (unlike concrete)

Also thinking of forming processes, casting is related to wasting, i.e. carving the structure from a solid block by removing excess. This is widely known to exist and there are numerous monolithic buildings around the world from cottages and simple dwellings through to grand temples.

And thinking further, fabrication involves not only dry joining (which would be traditional masonry) but welding. Could a masonry building have welded joints by flowing lava in between the pieces of stone?
-- pocmloc, Jan 03 2023


Is lava rock suitable for construction? I'm no architect, but it seems to me that something so porous would make a terrible construction material. To quote Jariba from Enemy Mine, "not solid." A little Google searching indicates it could be very useful as an insulation material, but for any kind of load bearing? I'm extremely skeptical about that.
-- 21 Quest, Jan 03 2023


//Is lava rock suitable for construction? I'm no architect, but it seems to me that something so porous would make a terrible construction material.//

Are you thinking of pumice?
There are other types of volcanic rock, like basalt and in particular dolerite, which is very solid and tough.
-- Loris, Jan 03 2023


[21 Quest], it wasn't specifically lava I had in mind, but any kind of molten rock. And I'm sure some would be more suitable than others. It also occurs to me that there is probably a way of using acid to dissolve certain compounds instead of this rather energy-intensive approach.
-- nineteenthly, Jan 03 2023


Wouldn't any kind of molten rock harden with air bubbles inside it, resulting in structural inconsistency?
-- 21 Quest, Jan 03 2023


dig down far enough and bring the lava up by pumping water down.
-- pashute, Jan 03 2023


Ooh, what about obsidian structures?
-- 2 fries shy of a happy meal, Jan 04 2023


Don't you just hate it when you pay a high price for real estate and you find out that the floor is lava?
-- RayfordSteele, Jan 04 2023


Goddamn it, Ray. You made me snort my beer.
-- 21 Quest, Jan 04 2023



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