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Comment by throw0101c | Hacker News Reader

Insulating concrete form (ICF) is popular in some quarters:

* https://en.wikipedia.org/wiki/Insulating_concrete_form

Instead of setting up formwork [0] with rebar, pouring and curing concrete, and then spending time (=money) tearing things down, the formwork is an insulating foam that is left in place. One consideration is that you then have to put some paneling in front of it (on either/both interior and exterior faces).

Depending on the aesthetic you wish to have, you can have smooth concrete exposed or have textures, e.g., board-formed:

* https://www.youtube.com/watch?v=W1JLy8ZSH2Q

* https://www.youtube.com/watch?v=688MeG_RKRM

[0] https://en.wikipedia.org/wiki/Formwork

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I built a 100'x60' 2 story building using these blocks with just me at age 20 and a 16 year old kid. Spent the days building lego brick wall and laying and tying rebar. Cement day was mostly a rest day watching the pump truck fill the section of wall. This is a fantastic construction method in many climates. The biggest downside of raw concrete structures is the lack of insulation.

Amazing! How did you learn this at age 20? Now I feel like a pathetic underachiever

On this job. Pretty much read the instructions and off to the races. The GC that hired me stuck around for a week or so to make sure everything was going smooth then he was off keeping the supplies flowing and would just check in every few days. The ease of building with ICF is a huge draw. It takes zero experience with concrete or building forms.

Learning something new every day. Thanks much for this.

Ironic because the technology is called insulated concrete forms. Newer ones are supposed to have an ok r value unless the older ones were much different. https://buildersontario.com/icf-r-value

Yes, I was saying that ICF fixes the problem of concrete not being insulated. Without insulation a concrete building feels like a cave.

My neighbour used the same technique to built his house here in Germany together with his wife. Their house know fullfils the requirements for one of the highest insulation standards here in Germany, called "Passive House". So I assume there must be great insulation materials available that can be attached to the outside of the walls.

there is a blogger that built a 'momplex' for her mother and mother in law in Alaska out of ICF forms, and she has some great blog posts on how they built it, the steps and work involved, as well as many plans and designs for the furniture, cabinets, etc, she built for inside the duplex. Her site is execellent for people interested in learning about woodworking, but the momplex series is facinating

* https://www.ana-white.com/woodworking-projects/maincategory/...

Ha, I've used a couple of her plans to build simple furniture. I didn't know about this backstory. Neat!

I was surprised to see a concrete pour below freezing temperatures. I'll have to read more about that.

The curing process is exothermic so it's possible the insulated forms keep enough of that heat in to make the process work even in the cold.

I once had to patch some broken pavement for insurance during mid December when it was 38 F out. After some research and speaking to a friend I covered the wet concrete with a trash bag and placed an old cargo blanket on top for insulation secured with a sheet of plywood weighted down with rocks. Cured just fine and ins agent was happy.

They do concrete work in Canada in freezing temps all the time. It just can't be "too cold" or even the insulation / heating isn't enough. But in general 38F is "laughable" so to speak ;) Seen them do it in sub 0 (C of course, it's Canada) all the time.

The Orlando Public Library is a little too brutalist for my taste, but is an interesting example of board-formed concrete:

https://en.wikipedia.org/wiki/Orange_County_Library_System#/...

Yeah a big downside of concrete construction seems to be that a significant proportion of builders/architects just say "fuck it, we'll leave the bare concrete exposed" and you end up with monstrosities like that.

They're not saying "fuck it", it's a deliberate aesthetic.

Not all bare concrete construction is a brutalist nightmare, look up Tadao Ando's work.

This is pretty much the first thing that came up when I searched for him:

https://lh3.googleusercontent.com/p/AF1QipPq8IzhBMH8PJBuKcVS...

ngl I think it looks pretty good. Way more visual interest than I expected

There's also some inversions of ICF where the insulating foam is on the inside and the concrete blocks are layers on the outside. OmniBlock is the manufacturer that I can remember but there may be others.

Not sure what the tradeoffs are but I'd assume two big pros are (1) concrete's easier to attach things to and (2) concrete can be directly finished both on the exterior and interior.

I'm not sure how people run electrical and other utility through these. And I'd expect that half the inspection / code in the US has no idea how to handle either ICF or related, but I'd love to be wrong.

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