best method for perlite insulation on dome

[builder brad]

what is the best way to finish off a dome that has 3-6" of ceramic fibre blanket insulation. I want to use 1-2" perlcrete and then a skim of external plaster/stucco and already have the fibre blanket held on place with a well secured chicken wire mesh that is streched tightly across the dome.

From the FB instructions I can see that a second mesh layer is created and the perlite mix is pushed through this. Is this absolutely necesary, or will it be easy to apply the perlite mix onto the blanket?


Brad

[nissanneill]

Re: best method for perlite insulation on dome

Hi Brad,
you certainly have a heap of insulation!.
I only put on a 1" super wool blanket and then 3 x 1" layers of vermiculite cement, See:

http://www.fornobravo.com/forum/f21/...-4-a-2045.html

permalink #8.
I put over the blanket, some chicken wire and then managed to lather it all with vermiculite cement. This is quite difficult to work and I added a little fireclay to make it stickier. I started at the very top and worked my way down and around ensuring that I always trowelled the mix in an upwards direction. You will find it out when you try out. I have given all my experiences and tips in my build postings.

Neill

[david s]

Re: best method for perlite insulation on dome

It is easier to apply the mixture from the bottom up, so you have something for it to sit on. The more cement,lime or fireclay that you use, the more you will reduce its insulating value. A 10:1 vermiculite/cement is sufficient to hold the mix in place and it will set up quite firm so you can stucco over it easily.