[Duchess47]

He mentioned the preformed concrete used for parking garages, freeway overpasses - that would be pretty hard to tear down and would go up pretty fast where terrain allowed. I don’t know if that would be his actual solution but it sure sounded good to me. :)

[bigtoona]

The wall would be like building a 4 lane highway as far as work effort and material. I’m pretty sure the country that put men on the moon can get it done and keep it on budget.

[spokeshave]

He mentioned the preformed concrete used for parking garages, freeway overpasses -

Not only that...but with 3D cement printing technology the wall can be printed in place:

and