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]

Re: perlite -portland mixture for oven floor

How big is the area you are pouring?

Width and length?

[MIKIPAL]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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

[asudavew]

Re: perlite -portland mixture for oven floor

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]

Re: perlite -portland mixture for oven floor

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

[CanuckJim]

Re: perlite -portland mixture for oven floor

Miki,

There's no reason to stop now in your location. The only time you do is when freezing temps are forecast. In your neck of the woods, that's probably not until mid November. Fresh mortar cannot be allowed to freeze, and it takes 28 days to cure.

Jim

[asudavew]

Re: perlite -portland mixture for oven floor

[QUOTE=MIKIPAL;16630will 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[/QUOTE]

I'm glad you got it done.

Too bad the weather is changing.
It's still in the 90's here.

It doesn't look like winter is coming here this year.

[asudavew]

Re: perlite -portland mixture for oven floor

Hey Jim,

Did I do something wrong with my calculations?

He ended up needing 6 bags of perlite....

Just curious.

[Acoma]

Re: perlite -portland mixture for oven floor

Miki,

There's no reason to stop now in your location. The only time you do is when freezing temps are forecast. In your neck of the woods, that's probably not until mid November. Fresh mortar cannot be allowed to freeze, and it takes 28 days to cure.

Jim

Jim, what about insulating blankets? The ones used to keep foundations warm after pouring during winters? Would that keep one working, or is it too risky?

[Acoma]

Re: perlite -portland mixture for oven floor

Allow me to re-phrase the question. If fresh mortar is not allowed to freeze, and it takes 28 days to cure, how long after using the mortar can freezing temps be tolerable? Anyone?