Michigan WFO Brick Oven Photos Discuss Michigan WFO in the Good Background Information forums; Thanks Frances That sounds reasonable. I think learning to use the WFO is when the fun truly begins....

[mannextdoor]

Thanks Frances

That sounds reasonable. I think learning to use the WFO is when the fun truly begins.

[staestc]

Good points Frances Thanks!
Travis

[mfiore]

Originally Posted by staestc

Mike,

Make sure it's good wine

I should have had two bottles. Not my finest day.

I decided to redo the outer arch. I know it was the right thing to do. It just didn't look right.

I tackled it with an angle grinder, trying to cut through the mortar joints of the center 7 bricks. The heat stop was quite hard, but I was able to cleanly make cuts 1/3 the depth of the joint all the way around. The bricks remained securely fastened to the others and would not budge.

I tried to tap them out with a small chisel. Nothing. "Dad, why are you worried about them falling if you can't even get them out?" Grrrrr...

A few more hits. Finally, the entire arch came down in big chunks. So did the side arch support on the left and the first few bricks on the right. Chipped a brick on the way down. I spent a great deal of time cleaning up, grinding the old mortar off the bricks. Getting ready to rethink my plan. I'll wait to rebuild later in the week. The temps were high 30's today and quite windy. Not a great day for laying brick. I hope to regroup and try this again later in the week. I have one day off this week, and working all weekend. I'm afraid I may have run out of time before winter. We'll see.

Sorry, no photos. I couldn't bear to take any today.

[egalecki]

It'll be ok, Mike. I think it's supposed to be warmer here next week, so maybe it'll stretch to you? I think the high here was about 35 today, and the wind was gusting to 35 mph. Ugh.

If it bothered you that much, you were right to take it out. Even if you'd covered it up with more brick, you'd have known it was there. Turn the chipped brick to where it won't show- if it's not huge it won't matter structurally.

Maybe a tent with sidewalls and a heater would lend you a little more time?

[Les]

Sorry to hear that Mike - had to be a huge set back. With the unknowns of thermal expansion, I think it was the right thing to do. If it's any consolation, when I built my island, there was an area I didn't like. Tore out around 35 bricks, invented cuss words that have never been written, and lost 2 days of hard labor. Stay positive, at the end of the day it will be good.

Les...

[dmun]

The converse to the theorem "if it looks right, it is right" is that sometimes you know that something just has to go. I know it's a pain right now, but you'll be happier replacing something that bothered you enough to take a hammer to it.

[james]

Mike, I know that feeling. Everything will feel a lot better with a fresh set of eyes and you will feel a lot better about the final result. I once took our a huge amount of oak flooring and my wife thought I was absolutely crazy. "No one will even know..." But I just had to re-do it.
James

[Frances]

Originally Posted by mfiore

"Dad, why are you worried about them falling if you can't even get them out?"

Gotta love having kids - they make building an oven double the fun, right?

Usually I'm not a great fan of heated tents in winter, but in this case so that you can safely finish and cure your oven, it sounds like a good idea...

Not long to go now, you'll be done before you know it!

[mfiore]

Thanks for the encouragement and support. I know in the long run, it'll all be just fine.

I have some remaining chimney questions. I had previously inquired about round vs square flue tiles. It appears that the square flue tiles are measured by the outside measurements, while the round are from internal dimensions. No logic, but I'm sure there is a reason. As it turns out, according to Superior Clay website Superior Clay Flue Liners
an 8.5x8.5 square flue tile has an effective area of 49 sq inch, while the 8inch round has an area of 50 sq inch. Essentially the same.

How important is the taper as you go up?

I plan to build a tapered vent entry into my arches. Mine is not done yet, but will be similar to this



The bottom dimensions will be about 4.5x 21.5 inches, tapering up to a dimension of 4.5x 12.5 inches.

Locally, I can find 8x13 inch flue tiles that will span the opening. This would be in increase in the effective area as vent opening transitions into the flue tile. Will this cause a problem?

Is it important to alter the flue tile for the chimney to continue to taper as it goes up (like dmun and Les did)?



Even more importantly, can my arch support this weight?

Thanks in advance. This chimney stuff is giving me a headache.

[Dutchoven]

Mike
I am glad you did it now because I know it would have eaten at you if you didn't...also I am sorry you lost a few bricks on the supports but I think they may have become an issue and that is why they came out...now you get to redesign the vent area and have an experience to draw from albeit not a happy one...as far as the chimney goes tapering the flue run aids in the draw because it creates a constriction and thereby a difference in pressure(bernoulli's law) and virtually sucks the gases out...it is not important that you create a tapered flue tile like dmun and les(although they are excellent work)...you can do it as masons for many years have done and create it using brick and then stack the clay liner on top of a nice flat surface...you can go from simple by setting each successive course inside the other(called corbeling) or you could angle the front and back sides and stack the bricks up along the sides to create the taper...smooth transitions are excellent but with something like a brick oven I don't think a few edges would negatively affect anything...as far as weight is concerned if you support the sides of your doorway arch well enough it would carry a huge amount of weight...and if you don't have to build a very long chimney...as in 1 or 2 clay flue liners there sertainly is no problem...dmun had quite a tall chimney on his as I remember...
All the best!
Check out this website to learn a bit about stability and design principles in arches and domes...cool stuff...
Auroville Earth Institute is a research, design and developing agency for vaulted structures, construction of various Vaults, Arches, Domes (VAD).
Dutch

Originally Posted by mfiore

Thanks for the encouragement and support. I know in the long run, it'll all be just fine.

I have some remaining chimney questions. I had previously inquired about round vs square flue tiles. It appears that the square flue tiles are measured by the outside measurements, while the round are from internal dimensions. No logic, but I'm sure there is a reason. As it turns out, according to Superior Clay website Superior Clay Flue Liners
an 8.5x8.5 square flue tile has an effective area of 49 sq inch, while the 8inch round has an area of 50 sq inch. Essentially the same.

How important is the taper as you go up?

I plan to build a tapered vent entry into my arches. Mine is not done yet, but will be similar to this



The bottom dimensions will be about 4.5x 21.5 inches, tapering up to a dimension of 4.5x 12.5 inches.

Locally, I can find 8x13 inch flue tiles that will span the opening. This would be in increase in the effective area as vent opening transitions into the flue tile. Will this cause a problem?

Is it important to alter the flue tile for the chimney to continue to taper as it goes up (like dmun and Les did)?



Even more importantly, can my arch support this weight?

Thanks in advance. This chimney stuff is giving me a headache.