Another thing I cannot find in China

[Filthymutt]

Ok, Hardibacker board. It's a brand name. Can someone give me a generic name? Because thus far I can not find Hardibacker in China nor a translation into Chinese (Mandarin).

Also, is it absolutely necessary? What's its purpose? It's not an insulator as that's on top of the concrete layer. Can I not just pour concrete on top of my plywood forms?

From the pictures in the plans the hardibacker seems to cover the holes in the cinder blocks, so why are we told to block them up with the empty cement bags?

Also, if you are pouring concrete atop the Hardibacker why do they tell you to use a release agent on plywood that is not after all in direct contact with the concrete you just poured?

Thanks,

Bob

[Bacterium]

Re: Another thing I cannot find in China

isn't if fiber cement sheeting (Hardibacker is probably a US brand?).

[mikku]

Re: Another thing I cannot find in China

You don't need hardee backer board, hardee plank or anything else like that. You can make your form out of anything, plywood, osb, drywall, lumber, metal, as long as you are going to strip it out later. There is a lot of crap information on this forum--use your common sense when working with concrete. Actually there is some good formply around that is painted already. I just put a sheet of plastic between my plywood and the concrete...when you strip the form it comes out glassy smooth!

Use what you can find. In another thread someone said that you could use cow shit and sand to make the mortar to hold the bricks apart. If you want a nice working oven forget about the bricks and use castable. Then you do not have to be a member of the "cracks club" and worry why your dome is cracking apart.

I am finding out that the nice thing about WFO's is using them. Get one built as easily as you can--for as cheap as you can--use your own judgement and just do it! I have over-fired my oven on the curing cycle and everything seems fine. Tonight I threw a whole bunch of kindling into the oven and in less than an hour, the dome had cleared--inside temps were over 400C. Cleared right to the floor! Pericrete was cool--same for render. Maybe approaching dry!

Once you have an oven that you can burn---then you can use it as a focal point for gatherings... Could be like "Sams' Place" in Cheers! Place to enjoy good food, experiment with cooking, experiment with drinking, place to relax! That is the Magic of the WFO--it makes a place to "gather"!

Close enough is good enough in making an oven. All that you are trying to do is keep a fire in one place long enough to cook something. Cavemen did it with piling rocks around a fire. Your smarter than a cavemen--otherwise you could not fly choppers! If you want your oven to stay hot longer, add as much insulation as you can afford... If you want to make a statement--clad it in gold leaf like some of the Buddhas!

Starting to enjoy cooking for free! Maybe I have to become a tree hugger!

[rsandler]

Re: Another thing I cannot find in China

Hardibacker is a brand name for cement board, sometimes called cement fiber board. Also might be sold as tile backer board, as the standard use is as a base for tiled walls and floors in bathrooms.

Cement board shows up in two places in the Pompeii plans. If you wanted to, you could use cement board instead of plywood to make your forms for the structural slab. The advantage there is that you can lay the cement board on top of your block stand and leave it in place, whereas you have to be able to fit the plywood into the hole in the middle of the blocks and remove it once the concrete has cured. Nearly everyone uses plywood though. One exception is Bruce's build: http://www.fornobravo.com/forum/f6/3...lly-19181.html.

Cement board is also used for the walls of an enclosure finish, rather than plywood, as it is moisture resistant and non-flamable. Given how well insulated most WFOs are, I'm note sure that is strictly necessary, but that's what the plans recommend, and it's probably good practice in a "belt and suspenders" kind of way.

Which is a long winded way of saying, if you can't find Hardibacker or some substitute, don't worry about it--you don't need it.

[UtahBeehiver]

Re: Another thing I cannot find in China

Filthydog,
Like Mikku said, use what you have available in your area. Lots of ways to skin the filthycat.

[Filthymutt]

Re: Another thing I cannot find in China

Thanks guys, Yea I didn't think it made too much sense to begin. I've got my plywood bottom up for the hearth today. Hope to finish the forms this weekend. Still need to form my workspace my sink area and the base for the BBQ too. If I can get it all done maybe I can pour on Monday.
I'll consider the castable too but maybe it's a masochistic tendency but I really just like the brickwork side of it.
Have a great weekend fellas

[TropicalCoasting]

Re: Another thing I cannot find in China

Also called cement sheet

[Filthymutt]

Re: Another thing I cannot find in China

Thanks but I'm going with plain plywood forms covered with plasti sheeting.

[stonecutter]

Re: Another thing I cannot find in China

Use what you can find. In another thread someone said that you could use cow shit and sand to make the mortar to hold the bricks apart.

I hope you know that comment was just a metaphor and not meant to be taken literally.

[david s]

Re: Another thing I cannot find in China

In Oz it is commonly known as "fibro"

[mikku]

Re: Another thing I cannot find in China

called "ushi-un" here,
BTW chicken moist
Banana bread burnt
"morning after" muffins--oven too cool, not saturated from slow burns
Pizza tasty
Today Finnish Flat Bread
Maybe some "pulla" if I can scare up some cardamon pods.
Day to enjoy spring

[Laurentius]

Re: Another thing I cannot find in China

called "ushi-un" here,
BTW chicken moist
Banana bread burnt
"morning after" muffins--oven too cool, not saturated from slow burns
Pizza tasty
Today Finnish Flat Bread
Maybe some "pulla" if I can scare up some cardamon pods.
Day to enjoy spring

I have cardamon if you can't find any.

[Filthymutt]

Re: Another thing I cannot find in China

Yea thanks ;-)