Anyone know why it isn't more popular outside of Europe? seems like a perfect use for recycled glass that is not suitable for glass bottles.

One of the biggest companies manufacturing foam glass is actually based in the USA and has many production sites in Europe.

The insulation properties depend on the chemical composition of the glass. With recycled glass, the chemical composition is not fully under control and therefore they limit the amount of recycled glass.

Production of cellular glass (also called foam glass) requires, even with recycled glass, a lot of energy. That makes it one of the most expensive inorganic insulation materials.

My guess would be that insulation wasn't taken that seriously until recently, and construction probably isn't the most fast-moving industry out there.

It also has some extreme insulation properties: it doesn't look like it really absorbs or lets through any moisture or air. There might be cases where that isn't ideal.

But living on the fourth floor of an old building with central heating in the basement does make me wish all the pipes were insulated with that material instead - it's absurd to have to wait many minutes for warm water to come out of the tap or shower because so much heat is lost along the way.

Even if it was insulated, you don't want warm water standing in pipes for a long time. This is usually solved by adding a pipe from the farthest point back to the boiler and circulation pump.

Which also has the nice property that the water in the pipes is always warm. You get a hot shower almost instantly.

Huh, hadn't considered that, but yeah, that would definitely be a health risk. Thank you!

You mention doubts about moisture or air permeability. It's a uniquely breathable material.

Oh, my apologies! I got the impression that the process of making them has the end-result of lots of closed off bubbles. But you're right, reading the wiki page again shows otherwise:

> Sound-absorbing Foamglas® insulation is more than 50% open cell bubbles, and heat-insulating Foamglas® is more than 75% closed-cell air bubbles, which can be adjusted according to the requirements of use through changes in production technical parameters.

https://en.wikipedia.org/wiki/Foam_glass

Good question. I'd hazard guesses that there was a political dimension (the wikipedia article cites Soviet scientists developing the tech in 1930s) and that insulation wasn't taken seriously enough (heaters are cheaper to install and energy was cheap).

"Fibreglass" type insulation is commonly used in north america and is made in part with recycled glass.

https://www.owenscorning.com/corporate/sustainability/produc...

Is this meant to replace rock wool in the walls or are the bricks used to replace the structural part of the building and used as load bearing building bricks?

There are several forms. Some of the most popular ones: - Blocks. From a technical perspective, these are perfectly usable as structural wall material in most use cases. Excellent insulation, breathable, moisture resistant. It is more expensive compared to traditional brick though. That's a big reason its use is usually confined to lower layers in touch with moisture. - Aggregate. Used as a structural, insulative anti-capillary layer below concrete slabs, wooden floors or wooden (!) foundations. Moisture barrier and insulation around some moisture sensitive houses also. Very popular in some areas as excellent breathable insulation for renovation of historical buildings. Used below roads in Scandinavia too to prevent frost heave. - Granulate. Mixed into concrete or plasters to improve their insulation qualities. - Custom shaped inert insulation for pipes, ...

Breathable? What the hell are you talking about? The vapor diffusion resistance of foam glass is pretty much infinite.

You're absolutely right about some of the foam glass materials. Not everything is solid closed cell blocks though...