Right Materials for Igloo Shaping Casa 80

[006]

Reading the installation manual at https://www.fornobravo.com/PDF/residential_install.pdf

"First, you can create the Igloo using stucco lathe and insulating concrete. The insulating concrete is then covered with a thin finish coat of waterproof stucco."

Is the insulating concrete layer necessary if using 3" insulation blanket?

thanks

[Gulf]

That depemds on how "pefectly" formed that you want the igloo to be. Though, the balnket insuation can be fitted fairly unifornily, it takes a little effort. The vermiculite or perlite concrete can help to get back to a more symetrical dome shape.

[006]

HI Gulf,

thank you for your response. I ended up using the insulating layer based on your suggestion and the dome ended up being fairly spherical
thank you for your help

[jchrisharris]

What type of insulating concrete did you use?

[006]

I mixed vermiculite with the cement mix until the texture looked good. Unfortunately It has been a while so I don't remember the details. I do remember that I tried to use 5:1 vermiculite/cement mix suggested by other threads and the texture did not feel right so I probably ended up doing 2:1 or even less.

[UtahBeehiver]

Attached is a recommended ratio for either under the floor or over the dome. 2 to 1 is really not a insulating medium but rather more structural.