My Modified Barrel Vault in Texas

[Tscarborough]

Re: My Modified Barrel Vault in Texas

First, I will assume you didn't permit it, since it is built hard up against the house. Second, you will probably want more insulation on the back wall, and possibly on the sides as well. It is hard to tell from the pic, are those split firebrick on insulating blanket, or are they inset? You should also make the arch in running bond and temporarily brace it until you figure out some way to permanently do so (like filling the "house" with a perlcrete mix instead of loose fill).

[Tscarborough]

Re: My Modified Barrel Vault in Texas

Sorry, I am in the middle of cooking pizza. I will be done in a little while and post again.

[perks1018]

Re: My Modified Barrel Vault in Texas

Reconsider what?

[brickie in oz]

Re: My Modified Barrel Vault in Texas

I was hoping to see it finished as it is Tom.....

[Tscarborough]

Re: My Modified Barrel Vault in Texas

I would stop right where you are and reconsider.

[perks1018]

Re: My Modified Barrel Vault in Texas

Here's what it looks like today.

[perks1018]

Re: My Modified Barrel Vault in Texas

The bricks soaked an average of two days in water prior to cutting with a 14" diamond blade. Not so much dust as there is thick powder blasting out all over my legs and feet and cat, which later dries and blows everywhere. Anyway, I gave up trying to upload photos to this forum and sent them to Photobucket. Pictures by perks1018 - Photobucket Apparently I'm the first to use the fornobravo name there so I got it. Anyway, the photos are up to date.

I don't want to belabor the "outward thrust" thing. My understanding of the physics (which is none too sophisticated) is that the arch transfers its weight down to the oven floor which, being itself immobile, carries the weight to its failure point. While I understand that there is always going to be "outward thrust", it must be one of those factors which is not really consequential in a structure of this scale. Agree to disagree.

[Neil2]

Re: My Modified Barrel Vault in Texas

"Protect your lungs."

In addition to what Dmun said, it is very useful to cut/ grind everything wet.

It addition to significantly reducing the fine dust it also greatly extends the life of the cutting edges. If using a chop saw with masonry blade, soak the bricks first (until bubbles stop coming out). Also have a squeeze bottle handy so that you can get some water into the cut if it runs dry. The motor and switches on a chop saw are up top.

[brickie in oz]

Re: My Modified Barrel Vault in Texas

Unless you have sideways thrust the barrel vault will fail over time no matter how ingenious your plan is.
If it is a vault straight off the hearth as I suspect you mean with no side walls, it will still move.
Ya cant beat gravity.

I bonded the end walls of my barrel to help eliminate this plus it has the weight of the chimney sitting upon the side walls (720Kgs) that should stop it from going anywhere....fingers crossed.

[perks1018]

Re: My Modified Barrel Vault in Texas

Oh, I definitely wear a respirator but the dust is EVERYWHERE, and thick in spots. I'm sure it is destroying the chop saw bearings and the cat is much less gray than before. As far as outward thrust is concerned, it is now only a fraction of what it would be multiplied by the sidewall height. I'm probably not expressing that in true engineering terms, but you get the drift.

[dmun]

Re: My Modified Barrel Vault in Texas

currently researching the toxicity of fire brick dust

There's nothing toxic, per se, but none of this stuff is good for your lungs. Get a good respirator, and avoid silicosis twenty years hence. Protect your lungs.

[Neil2]

Re: My Modified Barrel Vault in Texas

"walls of the traditional barrel vault which then have to resist the outward thrust "

There will still be outward thrust. All masonry arches exert outward thrust whether siting on a wall or on a slab.

[jacktheknife]

Re: My Modified Barrel Vault in Texas

Perks1018,

Howdy, a good idea cutting the corners off all the bricks so that they line up, all fit together right with a solid edge. 50 bricks and even though I am less than a week 'new at this' the design is forming in my mind. If I cut the same angle on 50 bricks they should fit together on each row.
{do they still fit as the circle gets smaller? or do I need a different angle each row?}
And just need stacking up with refractory mortar.
Great forum and the WFO is forming the nucleus to the entire east yard landscaping project which has been dormant for 10 years since my 'wreck'.
{I just had a home made Pizza}

A great forum.


Y'all take care...


Jack the Knife

[perks1018]

I call it modified because I intend the vault to rise directly from the oven floor in a semicircular arch. 36" oven floor will yield an 18" high dome height. I did the math and worked the numbers around the dimensions of a standard (at least locally in Corpus Christi) fire brick (9"x4.5"x2.5"). The physics is actually better as well as the vault transfers its weight directly to the floor rather than the walls of the traditional barrel vault which then have to resist the outward thrust of the vault dome. So I have a 36"x36" nominal, 31"x31" actual oven floor. I cut 7.5 degree bevels on the side of each brick (48 bricks in the dome, 96 cuts, not counting the two I screwed up- currently researching the toxicity of fire brick dust) so that they would produce a natural semicircle when stacked and mortared.