perlite -portland mixture for oven floor

[MIKIPAL]

Hi all you pompeians,going to pour my insulation 5.5 perlcrete tomorrow and dont know if i have enough material--2 -90 lb bags of portland and 3 -4 cubic bags of perlite--think its enough? hope to finish the stand and shut down for the winter and continue the pompei dome in the spring. couldnt get this far if not for f/b .pretty good for an settegerian.hope I can get help on this.thanx

[asudavew]

How big is the area you are pouring?

Width and length?

[MIKIPAL]

The insulation layer is 72" by 84" ,just dont seem like portland and perlite will be enough volume to fill the 5" layer.what do you think guys,am i wrong?how much did you use?thanx

[asudavew]

84"= 7 feet
72"= 6 feet

5"= .42 of a foot

7'x6'x.42'= 17.64 cubic ft

You have 12 cubic feet of perlite.
For a 5 to 1 ratio of perlite to cement you will mix in about 2.4 cubic feet of cement.
12+2.4=14.4 And usually the wet mix has a lower volume than the dry ingredients.

I think you will need another bag of perlite. Or you might just go with a 4" insulating layer.
4"= .34 of a foot
7'x6'x.3= 14.28 cubic ft.

Hope this helps some.

[MIKIPAL]

hey thankx a lot --that gives me a good idea of how much i need..dont want to run short in the middle of a pour.Is there no sand added? seems like a weak mixture without samd.

[asudavew]

No problem.

Better to have too much than too little.

Plus any extra that's leftover can be used to insulate the dome later.

Don't forget pictures!

[MIKIPAL]

will load pictures as soon as i know how..computers are new to me and just getting to navagate is a problem---will try soon.ciao

[MIKIPAL]

Sand is not added to the perlite -portland mix?seems like a weak mix for support of the igloo .

[asudavew]

No sand.

Just Portland cement, perlite, and water.

It gets pretty stiff!

1 part cement to 5 parts perlite by volume.

Mix the 2 together dry first. Get a good coat of cement on all the perlite.

It will look like clay cat liter.

Then add water. And just enough to hold it together.
I could just barely squeeze water out of mine with my hand, and it was probably a bit too wet.

I have a whole series of photos that include pouring the thermal layer on Picasa, in the album titled "Oven Mission 4 - The Insulating Layer", if you are interested in looking. They may be helpful.

Good Luck!

[MIKIPAL]

needed 3 more bags of perlit to finish stand.seems like 3 bags covered half of the stand---6 feetx7 feetx 4".mix 5 to 1 .but got it done and looks good--thanks for the pics -helped me a lot.great project .will continue in the spring for the igloo..the leaves are starting to fall here on long island and the colors are changing.good luck,ciao.mikipal