Vermiculite vs. Perlite vs. blend Getting Started Discuss Vermiculite vs. Perlite vs. blend in the Pizza Oven Design and Installation forums; Is there any difference between vermiculite and perlite? I have seen several ovens with a vermicrete hearth insulation layer but ...

[Adrian]

Is there any difference between vermiculite and perlite?

I have seen several ovens with a vermicrete hearth insulation layer but perlite+concrete dome insulation. Is this for a reason?

Some ovens even use a blend (mostly 2:1) of vermiculite : perlite in their insulation layers.

I'm confused! All information / recommendations appreciate for an ingloo-style pompei brick oven.

[dmun]

They both work fine. They are different colors and textures (vermiculite is brown cubes, perlite is white spheres) I used the perlite, and it's a little easier to see when it's fully mixed in, because the white turns grey, but it's mostly a factor of what's available and affordable.

[Xabia Jim]

I used it under my hearth just fine 5.5 inches and over the dome as well. By blending the portland in the water I was able to mix in a lot of perlite.

[david s]

Perlite is a slightly better insulator than vermiculite, but is also slightly more expensive (at least it is where I live) I prefer the vermiculite to work with because perlite seems to have some really fine particles that are irritating if you breathe them, the vermiculite doesn't seem to have this problem. I guess these materials vary a bit from place to place.

[thebadger]

I used perlite (couldn't find vermiculite).

I believe I used 5 parts perlite to 1 part portland. Tip - mix the portland and perlite (or vermiculite) first THEN add the water.

My 2 cents.

Dick

[glennb]

Bit of a noob question probably, but searching hasn't revealed the answer.
When measuring the ratios, is it by volume?
ie, 5 buckets of Verm + 1 bucket of Cement, and add water?
This seems like a lot of cement, as 1 bucket will be ~25kg or an entire bag of cement?

I'm nearly finished my dome, and will be thinking about the outer insulation soon.

[Les]

By volume

Les...

[asudavew]

Originally Posted by david s

I prefer the vermiculite to work with because perlite seems to have some really fine particles that are irritating if you breathe them, the vermiculite doesn't seem to have this problem.

I completely agree.

Stick with Verm if there is a choice.


Perlite also flies into the eyes.