Insulative blankets vs Pericrete any advantage to old fashion?

[mikku]

Now that I have chosen (because of cost) not to use blanket insulation on dome but only pericrete. I wonder--are there any (plural of plus) for pericrete vs blanket?

Maybe slower on heat up.. But that might prevent cracks? (Please no plumber jokes or Oz reference! ).

Looking for reasons to justify being cheap! But maybe a thoughtful discussion could result.

BTW this stuff is crazy to work with!

[david s]

Re: Insulative blankets vs Pericrete any advantage to old fashion?

Vermicrete or perlcrete is about half as insulating as blanket so you need to use double the thickness to get the same result. There is a cloud over the safety of blanket, but it is easier to apply and you won't need to dry it like v'crete or p'crete. Use as little cement as possible otherwise you drastically reduce the insulation value.

[mikku]

Re: Insulative blankets vs Pericrete any advantage to old fashion?

This is my project, right now.
Stopped for a cup of coffee.
I am using a 10:1 perlite to portland mix--gauging from your previous posts. water just enough not to pool. Each of my batches I have added slightly more water but nothing has pooled yet. This is like building a sand castle! I cannot imagine higher perlite ratios--so far this stuff shows adhesion and you can be re-shape as you go higher. I have 100 liters placed and ready to open the second bag. Maybe two more batches then call it quits. I think that if someone got good at this, they could do an entire dome without quitting. Tricky when you get around chimney opening--so far no pipe.

Any adverse qualities to perlite insulation?

The dust is probably equally dangerous to any particles from any fiber stuff. Once water is mixed, off comes the respirator.

A tip on tools- I am using a rubber float, used by tile guys for rubbing grout between tile. The surface is rough enough not to draw water to the surface and can be used to shave the surface down to get a smoother curve. Rubber glove/rubber float and eye-balling it. Thickness the width of my palm- 4 plus inches.