Sunday, March 18, 2018

Brick Oven Guru

I do not describe myself as a "Guru".  A recent caller asking guidance used the word.

gooroo/ "an influential teacher or popular expert." as defined on the web.

Okay...I suppose so.

After 431 posts, essentially offering every bit of knowledge I have gleaned, gained, or observed from building brick ovens, it is possible I've exerted some influence.

I continue to advocate for owner-builders while occasionally shamelessly self-promoting the traditions of true masonry and offering thoughtful approaches to the physics and aesthetics of brick ovens.

So, if you have stumbled upon this post looking for the most wise counsel on the building of brick ovens, it's all contained in the last 431 posts.  I will know you have read them when the blog counter goes nuts.

It has been a pleasure hearing from brick oven enthusiasts around the world via emails; your communications contribute to my bank of knowledge.

Many thanks, Mille Grazie, Muchas Gracias,

 تشكرات, Πολλά ευχαριστώ, Большое спасибо,


Tuesday, March 6, 2018

Brick Ovens: Europe's Gift to the World

The brick oven is solidly European.  Once we move away from arid places: Middle East, Southwestern U.S., Saharan Africa, the high altitude, ovens that are built to bake in are most often made of bricks, not as the commonly the clay/mud of arid places..

The brick oven is solidly European.  Once we move away from arid places: Middle East, Southwestern U.S., Saharan Africa, the high altitude, ovens that are built to bake in are most often made of bricks, not as the commonly the clay/mud of arid places..
The wetter, colder climates of Europe needed the permanence of brick and in most cases, the ovens were sheltered by roofs rather than masonry/stucco domes.



St. John USVI
Europeans brought their brick oven techniques to places they colonized.

North American ovens of the early colonial era and since were made of brick.

Thursday, March 1, 2018

Brick Oven Dome Building

All ovens start with a design idea.   Dome building however, is technical.  Just because an oven looks great from the outside, doesn't mean it will work if the physics of shape, thermal management, and flue design are wrong.
My personal oven in conservatory
TBO 36" at deck level
A sauna room was built under it as a way of providing a foundation with another purpose.
They do not share heat sources or flues.

More than 30 ovens later... there's more learned and more to add.  Precise dome bricks make a strong oven.

Domes, rather than barrel vaults produce even heat.

Note: Common misconception--the hole in the top is NOT the chimney!  It is the last part of the dome that needs to be closed.

Bricks pre-cut on styrofoam dome 

view from top before final chains 

The final space ready for keystones
Pre-cut and fitted keystones
TBO innovated this way of fitting the keystone.

View of dome roof from inside

Greek style oven by TBO
TBO collaborates with owners to make each project unique to person and place.  This oven was built due to the customer's heritage and taste.  An opportunity that exists with every oven TBO builds.

Wednesday, January 31, 2018

Brick Ovens Survive Apocalypse

Imagine your city two-thousand years in the future.  Imagine, or not, some event that would cover the city in twenty feet of ash.  Then imagine, uncovering the city.  What would you  find?  What would be left?

Pompeii, Italy is a post-apocalypse city.  Mount Vesuvius erupted in AD 29 raining hot ash on the inhabitants of Pompeii.  Those that didn't leave early became entombed.

Twenty-six bakeries survived.  Rather, twenty-six brick ovens survived; the bakers didn't.

Fast forward almost two millennia.

Fires sweep coastal southern California.  Many homes burn.  The Ventura brick oven I built, having a stone roof as well as masonry interior and exterior, is intact.

Some things are meant to last.  Our homes certainly.  Our friendships hopefully. Brick ovens, definitely.  

This ancient cooking device is nearly eternal.  Whatever your vision of apocalypse, be sure, brick ovens will be there afterwards.

Monday, January 29, 2018

Colonial Era Brick Ovens

Jan Steen: The Bean Feast
Imagine if they had pizza!
I have on occasion been asked to look at a colonial era brick oven, most often built on the left side of a fireplace/hearth.
These were used to bake bread, beans, and food other than pizza; try to imagine Puritans wanting pizza!  Heresy.

The conversation with owners of the ovens today goes like this:  "I can't get the oven hot enough for pizza!  What's wrong with the oven?"

Puritan family waiting for the oven to get hot
Answer: Bypassing a long historical explanation on why colonials didn't make pizza, I explain that the fireplace/hearth was burning all the time.  Colonials cooked everything on it, either in a pot hung from a hook or on spits.  The oven, part of the overall masonry, was always warm, may 180F or more.  A shovelful of coals from the fireplace would bump the oven up to baking temps and the ambient heat of the fireplace would prevent it cooling down quickly.

Trying to get a cold colonial brick oven to baking temps when there is a ton of cold masonry sucking the heat from it, is like shoveling snow into the wind.

Fiber blanket insulation over dome before roof goes on
That is why I isolate my brick ovens from other masonry and insulate them well.

The advent of the cast iron stove must have been as miraculous to colonials as the smart phone once was to us.

Workshop sponsored by Castine Historical Society
Last summer, I did happen upon a workshop in Castine, Maine given by an old-timer mason whose predecessors built colonial ovens.  It was interesting to see how casually he placed the bricks.  It reminded me how both practical colonials were and how imprecise an oven can be and still work.

Oven built on a sand mound form (later removed)

I personally get a kick out of making perfect domes.  Go figure!

Elongated dome TBO 48"x60" St. Charles, MO

Friday, January 26, 2018

Brick Oven Firing and the British Thermal Unit

A dry piece of hardwood has a certain amount of BTU potential.  To extract the maximum BTU's (British Thermal Units...not important really) from a piece of firewood may or may not be your goal when firing your brick oven.  Because I cut my own firewood and I've burned my own calories cutting that firewood, it is mine.  (Geek alert* One BTU=0.25 Cal...again not important to brick ovens).

 Therefore, having a relaxed firing where the addition of dry firewood to the oven is done slowly, will result in very little wood used to achieve high temperatures in the oven.  Recently, I got my 36" oven to 700F using six (6) pieces of firewood (average 5 pounds each).

I've noticed that the early fire is the most inefficient.  This is because the volatiles in the wood burn at different temperatures.  The early firing can only combust a portion of the volatiles.  The rest goes up the chimney.  Later, at about 400F, a second group of volatiles combusts as well, releasing more heat.

Back when I was a potter firing a wood-fired kiln, there was a third group of volatiles.  I remember putting a two inch diameter stick in the firebox when the kiln was about 2000F and flames would shoot through the entire kiln, up the 20 foot chimney and be seen spurting out the top.

BUT DON'T GO THERE with your brick oven.  2000F is white hot and a brick oven should never be close to that temp.

Gray, lazy smoke and a certain fuel-like smell is a sign that you have too much wood burning in the oven.  Let it clear.  That is the time when you're getting efficient heat and maximum BTU's from your  wood.

Thursday, January 25, 2018

Accentuate the Positive

TBO 36 with intentionally designed brick pattern patio
Oven is built on existing ledge outcrop

The following blog post arrives from my experience as a landscape designer and often applies to projects where a brick oven is being built.   

Perceiving an object requires that we distinguish it from its surroundings. The joke about a blank piece of paper being ‘a polar bear in a snowstorm’, applies to our perception.
Placement of TBO 36" in Ventura CA to frame view.
Oven is adjacent to home's kitchen
Painters and sculptors refer to positive and negative space. Positive space is the object we are able to perceive. Negative space is the background that allows us to see that object.

Siting the oven as a positive element is especially important with outdoor projects.

Positive and Negative space built into the oven design enhances the stonework
A yard or deck becomes 'complicated' when objects are placed on or next to it.  Choosing a location that doesn't 'interrupt' the space is important.  If the choice 'compliments' or 'enhances' the space, all the better.

Choice of stone color and shape accentuates the design.
We see the arch clearly because the stone is more formal
than the surrounding stonework

In landscapes, the tree is the positive and the sky is the negative.
Outdoor classroom by
Applying this to landscape design, we may choose to remove masses of confused greenery in order to accentuate a specimen tree. We may also take advantage of a mass of greenery by planting or building a contrasting form in front of it. We might ‘cut’ a hole in the greenery to form a dark shadow. Each of these changes creates the negative space needed to bring the desired focus to the design.

My former garden in Waterford, Maine

the house I designed and built in Lovell, Maine
Homes provide positive space; ponds and shadows negative space
Foreground plantings accentuate negative space.