Angle Iron 3/8 " ?

[Mike D]

So I asked this question in my build thread, but I am putting it here to see what other people did. The plans call for 3/8" angle Iron for the block construction. As I look around for 3/8" it seems like this is very thick for support (not to mention that I can't find this thickness at all anywhere). I have only found 1/8" thick 2"x2". Are the plans correct?

Thanks for the help
Mike

[dmun]

Re: Angle Iron 3/8 " ?

My thinking is that that row of blocks over the wood storage door is entirely unnecessary. It just constricts your wood storage. It doesn't really add any strength to the structure, because the blocks are pretty much just hanging there on the angle iron. It's a nuisance to cut away the blocks to get the angle iron flush.

I say, just put a couple of extra pieces of rebar in the front of your slab, and let the front be open. If, for aesthetic reasons, you want a lintel over the door, a bit of formwork will allow you to cast one at the same time as your slab, one that will have some actual structural strength.

[Tscarborough]

Re: Angle Iron 3/8 " ?

4x6x3/8" is normally used for CMU, not for required strength so much as having enough bearing surface. You could use 2 pcs of 2x2x1/4, one on either side, but I am with Dmun, really.

[Mike D]

Re: Angle Iron 3/8 " ?

I was going to use bond beam block for the top level to help tie things together a little more like Dino's (and I'm sure many others). I could use 2x8 lumber to form the top slab and just close in the bottom opening and on the inside. What type of rebar action do you guys think I would need?

Mike

[dmun]

Re: Angle Iron 3/8 " ?

What type of rebar action do you guys think I would need?

Really, this thing is drastically over engineered. A couple of extra pieces of 3/8 rebar should be a great sufficiency.

[Neil2]

Re: Angle Iron 3/8 " ?

I agree with Dmun. Just strengthen the slab above the opening. A couple of extra 3/8s are fine if they are anchored at the ends - either by hooking or by bending 90 degrees for 12 inches down into the wall or 12 inches along the side.

If you insist on angle iron, old bed frames work fine. You can get enough for 10 ovens for 5$ at the local thrift shop. Cut them up with a cut off disk on your angle grinder and paint the end with a rust paint. (If you don't have an angle grinder - get one. They are a very useful tool for building an oven. Go for a 5 inch angle grinder.)

[Mike D]

Re: Angle Iron 3/8 " ?

I do not need to use the angle iron. I like the idea of making the wood storage area opening bigger. The plans call for 1/2 " rebar in the hearth slab, did you guys use 3/8s? Can one bend 1/2" rebar easily?

[dmun]

Re: Angle Iron 3/8 " ?

did you guys use 3/8s?

Yes.

Can one bend 1/2" rebar easily?

No.
Even bending 3/8" is a struggle. The best way is to have two lengths of something like half inch black gas pipe, slide the rebar into the pipes, and move one pipe to bend the rebar. You have to bend it beyond 90 degrees to get a right angle, so it's best to make your bends before you pour concrete. Hammering on it does nothing but bounce the hammer.

[Tscarborough]

Re: Angle Iron 3/8 " ?

Find a hole, like on the bumper of a truck. Stick it in, and bend it. 3/8" should be easy to bend as it will be grade 40 or no grade, 1/2" may be grade 60 which is pretty hard to bend.

[Neil2]

Re: Angle Iron 3/8 " ?

"The plans call for 1/2 " rebar in the hearth slab, did you guys use 3/8s? "

You can use either. Note that 3/8 inch has about half the end area of 1/2 inch (.11 sq in vs .19 sq in). Therefore if the design calls for 1/2 inch on a 10 inch spacing you can substitute 3/8 inch on a 6 inch spacing.

3/8 inch is much easier to work with that 1/2 inch when it comes to bending with home tools. It is also slightly easier to ensure concrete coverage.

Note that many yards that sell re-bar will also have a hand bending machine like this for use by customers. These tools can cut rebar and can also put hooks on the ends. Lots of rental shops will also carry them.

[Lburou]

Re: Angle Iron 3/8 " ?

I do not need to use the angle iron. I like the idea of making the wood storage area opening bigger. The plans call for 1/2 " rebar in the hearth slab, did you guys use 3/8s? Can one bend 1/2" rebar easily?

FWIW, I've been successfull using metal conduit bending tools for 1/2 inch rebar. The long handle gives you a lot of leverage.

I'm using 3/8 inch rebar for my hearth slab though