Bread Oven

Construction of thelePanyol Wood-Fired Bread Oven

First edition 2002

Copyright 2002 by Maine Wood Heat Company, Inc.

All rights reserved. No printing of the contentsof this book may be reproduced in any formwithout written consent of the publisher.All inquiries should directed to: Albie Barden,Maine Wood Heat Company, Inc., 254 Fr. Rasle Rd.,Norridgewock, Maine 04957

Book Design: Christopher CavendishCover Photo and oven: Marcus Flynn, Montreal, P.Q.

Table of Contents

3

Introduction 7

The le Panyol Oven cores 11

Design and Construction 19

Assembly of the le Panyol oven core:Models 66, 99, and 83 31

The Domestic ovens cores; Model 66, 83, and 99 12The Professional oven cores: Model 120 and 180 15

Le Panyol oven cores and the legacy of the Roman Empire 7Principle of the le Panyol oven core 9

Calculating the height of your oven hearth 20Foundations 20Hearth slab depth 22Insulating your hearth 23Smoke throat elements and adaptors 24Additional mass and insulation 25Chimney Support 26Ash dumps 28Capping your le Panyol Oven core 28

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Preface 5

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Step - by - Step assembly 32Model 66: plan and sections 36Model 83: plan and sections 37Model 99: plan and sections 38

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Assembly of the le Panyol oven core:

Models 120 and 180 41

Introduction 42Supporting the Voussoir 42Applying the refractory mortar 44Curing 44Additional mass 44Model 120: plans and sections 46Model 180: plans and sections 58

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Appendixes 51

Appendix A 51

2004 Addendum 52

Ash Dumps, Dampers & Chimney Caps 52

Preface

5

A few miles below Lyon, along the

Rhone River in southeastern France (the

region of Provence), is a famous deposit of

white earth (Terre Blanche) that has been

exploited for two purposes since Roman times.

The color and minerals of the white earth

produces some of the world’s finest vineyards

(“Hermitage”) and also the very best all natural

material for making fire bricks for ovens.

The white earth of the ancient quarry in

Lanarge consists of two basic ingredients,

feldspar and kaolin clay, a result of natural and

exceptional underwater degradation of an

ancient granite deposit that was once flooded

when the waters of the Mediteranean were

much higher that they are today. The Terre

Blanche is removed from the ground with a

large bucket loader and transported less than a

kilometer to a huge modern plant that separates

the large particles of feldspar from the smaller

particles, then recombines the smaller particles

of the feldspar with the kaolin clay in perfect

proportions. Water is squeezed out of the new

sheets of kaolin and feldspar and continously

recycled. The moist sheets are loaded into a

lorry and carried over the hill to the historic

factory next to the Rhone, where the fire brick

shapes are made. With nothing added but a

little water, to the recombined all natural

quarry mix, the white earth is extruded into

molds, dried and fired in a modern rotary kiln.

When the shapes emerge from the kiln, they

are ready to be assembled into beautiful, heat

retaining, healthy, high performance ovens.

Whenever you travel in France, you can

see in old villages and city shops, communal

ovens and commercial bakeries. Inevitably, the

name embossed on the large arch fire bricks

defining the oven door opening, indicate that

the material used to build the oven cores, is the

famous Terre Blanche (white earth) of Lanarge.

Even at very high temperatures, the

white earth cooks the food safely with no toxic

emmissions and has been given the highest

possible rating as a cooking utensile by the

French government.

Now, after over a century and a half of

use in Europe, the famous Terre Blanche

material is available to North America through

the le Panyol oven core kits, made at the

ancient factory site of T’ain Hermitage along

the Rhone.

In the late 1970’s, the Maine Wood Heat

Co., Inc. introduced to North America the

concept of Finnish masonry heaters. Now, in

the new millenium, the Maine Wood Heat Co.,

Inc. is proud to introduce to the New World

another ancient, timeless, wonderful, wood

fired product line, the le Panyol oven core

series.

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Introduction1

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LE PANYOL OVENS AND THELEGACY OF THE ROMAN EMPIRE

Fire has been used to cook food for humancommunities since well before the practice wasrecorded in the annals of history. Along withwarmth and safety, the fire was a means to makefood more easily preserved and digestable, not tomention palatable. The fire was a sacredphenomena to our earliest ancestors and soonbecame enshrined in the artifacts of their lives; thespit, tripod and brazier, and earliest of all simpleovens, were among the first inventions to harnessthe energies of fire.

The first ovens to be built were made ofclay and therefore have not survived the agesintact. What we have of those earliest ovens is justenough to learn about the social structure of thecommunities that used them. Vitruvius, a Romanhistorian, recorded the shape and proportions ofthe ovens in use during his time. Since this firstdetailed record of wood fired bread ovens little haschanged in the overall design because little haschanged in the way wood burns.

Fire requires oxygen to burn and must beable to expel the products of combustion asquickly as it receives oxygen. The size and shape ofan oven can determine how efficiently the oxygenis delivered to the fire and expell its exhaust.

A properly proportioned oven will have adoor that allows oxygen to enter withoutinterfering with outflow of exhaust. However, ifthe door is too high then the efficiency of the ovenwill suffer because needed heat will escape.

An oven with a ceiling that is too low willforce the incoming oxygen and the outgoingexhaust to mix creating turbulence that slows bothflows. The net result is the fire will fail to burn

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vigorously and will smolder.An oven with a ceiling that is too high will

not give the the hot gases enough downdraft toallow them to escape and allow oxygen toreplenish the fire. As with the oven that is tooshort, the fire will become starved of oxygen just asit is getting started and will smother itself in itsown exhaust.

Fayol has adapted the canon of wood firedoven proportions devised by the Romansthemselves and created a truly unique oven fortoday. Fayol has maintained the proper oven todoor height proportions that are essential, butcreated an oven core that is simple and fast toassemble. With fewer pieces to assemble thanbrick-by-brick assemblies, the do-it yourselfer canbuild his or her oven core in under a day.

Another key element to a properlyfunctioning oven has to do with the mass of anoven. Mass or the masonry that the oven isconstructed of is its thermal storage. This is whatmakes an oven work. The heat generated by thefire is absorbed into to the masonry walls of theoven while the fire burns. As soon as the fire isremoved the masonry begins to release the heat ithas absorbed into the oven. If the walls of theoven are too thin then they will not be able torelease enough heat for the time necessary to bakea batch of bread. This does not mean that themore mass there is the better. An excessive amountof mass will absorb too much heat and cause youto burn more wood than needed and for a longertime period in order to bring the oven up tobaking temperatures.

Masonry is masonry is not masonry.All masonry is not the same in it’s ability toprovide optimal baking performance in a woodfired oven. The property of masonry to be a goodthermal storage medium is that it is actually a poor

Chapter 1: Introduction

8

conductor. Because masonry is slow to absorbheat/energy it is also slow to release it. What makesgood masonry for wood fired bread oven differentfrom poor masonry is its density. The more densethe masonry the better it will conduct heat intoitself, but also the quicker it will release the heatgiving a short hot cycle of baking. Masonry that istoo porous is too insulative requiring longer burncycles for inadequate bake cycles.

Since the era of the Roman empire theTerre Blanche has been celebrated for the naturalbalance of density/porosity that makes this clayexcellent for creating the bricks and tiles of thebest wood fired ovens in the world. Today, Fayolcarries on the tradition of producing only thefinest ovens from the same clay deposits onceheralded by the Romans.

Fayol has gone to great lengths to createthe best quality oven by combining the finestmaterials and time tested designs with moderntechniques.

From top to bottom: too tall, too short, too thin, just right

Chapter 1: IntroductionChapter 1: Introduction

9

Chapter 1: Introduction

THE PRINCIPLE OF THE LEPANYOL OVEN CORE

The le Panyol oven is a wood fired ovenusing the heat of the fire for baking breads, pizzas,pastries, meats, and vegetables. The fire is starteddirectly on the hearth of of the oven. Gradually, asthe fire progresses, the embers are pushed to therear of the oven so as to ensure even heating of theoven.

For baking loaf breads and other foods thatrequire even temperatures over an extended periodof time, retained heat of the fire by the oven wallsand hearth is used to cook. Once the oven hasachieved cooking temperatures, the remainingembers and ashes are removed, and the floor of theoven is quickly swabbed with a moist towel.Following a tempering to even the internaltemperature to roughly 600 degrees, food is placedin the oven and cooked directly on the hearth.

Another technique of baking in the lePanyol oven is called the direct heat method.Pizzas benefit from this method because of thehigher internal air temperatures that cook thecheese and toppings before the hearth can burnthe bottom of the crust. As with the retained heatmethod, a fire is started near the front andprogressively moved to the rear of the oven as itheats up. Instead of removing the fire entirely,leave some embers in the oven after swabbing thehearth and keep a small fire going in the rear or offto the side.

Start the fire near the oven door. Add wood gradually andpush the embers towards the rear as the fire progresses toachieve even heating of the oven.

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le Panyol Ovens cores2

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Models 66, 99 and 83 aresmall to medium volumeovens designed with thehome baker in mind. Theyare a great introduction to thepleasures of baking with awood fired oven, yet are largeenough to be useful to theartisan baker as well.

Models 120 and 180 are largevolume ovens designed forcommercial restaurants pizzaand for production bread andother pastry baked goods

Chapter 2: le Panyol Ovens

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Model 66 - Domestic oven coresInner diameter 26”Weight 825 lbs.Hearth tile footprint 39-3/8” x 39-3/8”Hearth tile thickness 2-1/2””Total core height 19-5/8”Inside height 12-3/4”Cooking surface 3.7 sq/ftWall thickness 4-1/2”Door opening 13-3/4” x 7-7/8”


13www.lepanyol.com for more about wood fired bake ovens

Model 83 - Domestic oven coreInner diameter 32-3/8”Weight 1188 lbs.Hearth tile footprint 52-1/2” x 52-1/2”Hearth tile thickness 2-1/2”Total core height 19-5/8”Inside height 12-3/4”Cooking surface 5.8 sq/ftWall thickness 4-1/2”Door opening 13-3/4” x 7-7/8”


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Model 99 - Domestic oven coreInner diameter 26” x 39”Weight 1100 lbs.Hearth tile footprint 39-3/8” x 52-1/2”Hearth tile thickness 2-1/2”Total core height 19-5/8”Inside height 12-3/4”Cooking surface 6.3 sq/ftWall thickness 4-1/2”Door opening 13-3/4” x 7-7/8”



Model 120 - Professional oven coreInner diameter 47 1/4”Weight 2420 lbs.Hearth tile footprint 65” x 65”Hearth tile thickness 2-1/2”Total core height 26”Inside height 17-5/16”Cooking surface 12.1 sq/ftWall thickness 6-1/8”Door opening 10-1/4” x 21-1/4”


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Model 180 - Professional oven coreInner diameter 70-7/8”Weight 4620 lbs.Hearth tile footprint 90-1/2” x 90-1/2”Hearth tile thickness 2-1/2”Total core height 29-3/8”Inside height 20-7/8”Cooking surface 27.5 sq/ftWall thickness 6-1/8”Door opening 13-3/8” x 25-3/13”



Notes

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Notes

Design and construction

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What your le Panyol ovenwill look like on the outsideis limited only to yourimagination. In this chapteryou will learn the essentialelements of the whole oven,how they affect performanceand how to design youroven’s exterior.

Chapter 3: Design and construction

20 The proper height of your hearth makes for a happy baker.

Section through the opening of the Panyol Oven

CALCALCALCALCALCULCULCULCULCULAAAAATING TING TING TING TING THE HEIGHT OFTHE HEIGHT OFTHE HEIGHT OFTHE HEIGHT OFTHE HEIGHT OFYYYYYOUR HEAROUR HEAROUR HEAROUR HEAROUR HEARTHTHTHTHTH

The height of the oven hearth should bedetermined by the end user for his/her comfortand convenience. Traditional oven hearths areusually at a height of 36”-40” above the floor.When planning your oven, determine first thethe oven hearth height you desire. The ovenhearth tiles in addition to the bed of sand or grogthey rest on will take a minimum of 3”-5”. Theslab supporting your le Panyol oven will take upan additional 4”-6”. For the casual home user itis not necessary to insulate the hearth tile fromthe supporting slab as they heat up quite rapidlyand provide a sustained baking. However, if youplan to use your oven frequently or wish to bakeon a more than casual basis, 2 1/2”-3” ofinsulation is sufficient. Add the thicknesses of thesupporting slab, insulation, the bed of grog orsand, and the hearth tile and subtract this sumfrom the height you wish to have your hearth.

FOUNDAFOUNDAFOUNDAFOUNDAFOUNDATIONSTIONSTIONSTIONSTIONS

All masonry construction including walls,fireplaces, and ovens, requires a proper reinforcedconcrete footing. Masonry footings generallyexeed the widthe of the wall or construction theyare intended to support by 6” on all sides andconsist of 12” of reinforced concrete placed oncompacted soil or undistured soil below the frostlevel. (Check with your local building inspectorfor the depth of your frost level.)

The reinforcement should consist of aminimum of standard reinforcing wire mesh in

This is the height above the floor that yourfoundation wall must come.


www.mainewoodheat.com for the latest design information

21 Typical concrete block foundation (top)and the Sono tubefoundation with the flared footing accessory (above)

6” squares placed in the lower third and a secondlayer placed in the upper third of the footing.Stronger reinforcement (recommended) can beachieved using 3/8” or 1/2” diameter steel rebartied together in a 6” grid and positioned in thefooting in both the upper and lower third.

Bend and tie short sections of verticalrebar to stabilize during the concrete pour. Oncethe footing has been poured allow at least 24hours before continuing. Concrete block orconcrete filled Sono tubes can be used to bringthe foundation up the level of the concrete slabthat will support your le Panyol oven.

A relatively new product that is widelymarketed has a flared plastic fitting that mountson a Sono tube which allows the concrete andfooting and column to be poured in one step. Asthese column and footing forms are set in theground they must be carefully plumbed with a

level and then trimmed to a uniform height. tolock these columns into a reinforced concretehearth supporting slab. one or two lengths ofrebar should be installed in each tube with aneight inch right angle bend three inches above theform that will later be tied into the rebar grid ofthe reinforced hearth slab.


22Diagram 3.2 Axonometric of Model 99 on a Sono tubefoundation. Note: the curved rebar embedded in the pilings.

Diagram 3.2 Section of Model 83 on a Sono tube foundation

Hearth slab depth (front to back)

The oven slabdepth, front to back,should be determinedsomewhat by the user.Each model has its ownstandard hearth tile layout.You can see from thebrochure, Fayol web site*and enclosed drawings,that there is room on the

* www.lepanyol.com

hearth tiles of each model (66, 99, 83) to lay thesecond full set of arch elements that have the 31/4" x 11" rectangular opening at their top. Forexample, with model #83, a 4" masonry veneerwall with no insulation in the front can thereforebe laid out around the 52 3/8" x 52 3/8" hearth,creating a total layout of 60 3/8" x 60 3/8". Theuser is likely to want a shelf or extended hearth infront of the oven, but this can still be built off a60 3/8" x 60 3/8" slab with cantilevered supportsunder the extended hearth slab.

If you use a non-structuralskin, let us say a metal stud wall witha concrete board and stuccoed veneer,you’d still want to calculate the 60 3/8" x 60 3/8" for a nominal 4" wall.And finally, you’d need a coderequired clearance of 2" all around tocombustible members and materials.Thus, the sides would need a space64 3/8" wide and the depth to theback would increase to 62 3/8". Thefront, of course, opens into the

room.



23Diagram 3.3 Axonometric of Model 99 with Sono tubefoundation. Note: the first course of concrete block canserve as the formwork for a vermiculite concrete slab.

INSULATING YOUR HEARTH

The hearth tiles laid in 1-1/2” to 3” ofgrog are naturally semi-insulative, providing asustained baking period without the addition of astructural heat-proof insulation beneath the tilesand grog. A casual baker, one who bakesinfrequently or for only a couple hours a weekwill be satisfied with the performance of the ovenwithout any additional floor insulation.Insulating your hearth, however will extend theperiod during which you can bake from a singlefiring.

If you plan on turning your hobby into anartisan bakery someday, then you should plan to

insulate under the your hearth now while it isaccesible and easy to do. For commercialproduction bakers, it is especially important tohave sufficient insulation under their hearths foroptimal performance.

There are several materials we have usedwith equal success.

“Skamol”A commercial non-toxic product now

available as a load bearing insulatingprefabricated block is a Danish product madefrom vermiculite and waterglass pressed under40,000 lbs., called “Skamol”. We are now usingthis product on some of our installations.

Vermiculite concrete slab

A low cost insulation slabcan be made from vermiculite mixed 3-4parts vermiculite (fine grain particle) to 1part portland cement plus adequate water.Large grain particle vermiculite (atticinsulation) is usable, but it will result in amuch softer slab. A 3” thick slab issufficiently thick.

“Ytong” (also called foamcement)Long used in Europe, this

lightweight structural insulation is madefrom autoclaved calcium cement (noportland cement.) I t can be easily cutwith a hand saw. It is available from theMaine Wood Heat Company.


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Isometric drawing of the smokethroat and adaptor Dimensions of the smoke throat adaptor

SMOKE SMOKE SMOKE SMOKE SMOKE THRTHRTHRTHRTHROOOOOAAAAAT ELEMENTT ELEMENTT ELEMENTT ELEMENTT ELEMENTS ANDS ANDS ANDS ANDS ANDADAPTADAPTADAPTADAPTADAPTORSORSORSORSORS

For the American market, with onlymodest masonry familiarity with traditionalFrench “hood” style smoke exhaust, Fayol hasdeveloped a second set of arch door elements,also made of Terre Blanche, the famous fired

Detail of smoke throat adaptor attachment

“white earth” of Lanarge,along the Rhone Valley inFrance. This new, made-for-America, set of pairedelements, when mounted,has a rectangular opening atits top which measures 3 1/4" x 11". Tocomplement these new elements, the MaineWood Heat Co. Inc., has designed and developeda heavy gauge stainless steel adaptor which ismounted with tap con screws and high tempsilicone or refractory mortar to this horizontalsurface. The adaptor makes the transition from3 1/4" x ll” to an 8" round in 10 “ height. Usinglocally available elbows and stainless pipe, theexhaust can be vented in any direction, intoeither a masonry chimney or a pre-fab chimney.



25Model 99 with a Sono tube foundation shows the layering ofinsulation and added mass.

ADDITIONAL MASS ANDINSULATION

Our friends in France suggest that the thickness ofthe oven elements should be added to with anequivalent thickness of grog or sand. Thus, if thewall thickness of the module is approximately sixinches, then they would add 6" of grog or sand allaround. Grog is 30% more effective as a thermalmass and insulator than sand. Grog, we think, ismuch more readily or cheaply available in Francethan here in the US and sand is often offered asthe cheaper alternative, but this loose fill layer ofmass has a couple of cautions associated with it.Maine Wood Heat Company will be stocking grogmade from Terre Blanche along with the ovencores.

1. Once the oven core is up, we suggest buildingthe veneer skin and placing 2" thick walls of semi-rigid mineral wool batts up inside the veneer wallbetween the hearth stones (tile) and veneer block.This leaves little room at the base of the ovenmodules for grog fill, but still plenty of room asthe voissoirs curve in to put extra mass on theshoulders and top of the dome. One canalso drape aluminum foil down the inside face ofthe mineral wool layer.2. Loose fill mass such as sand or grog might getinto and through any crack and into the ovenchamber. Even though the oven dome is entirelycovered with the refractory clay provided, andallowed to cure, a strong earthquake might cause acrack and allow this loose fill mass to migrate intothe oven or around the throat adaptor.

In an active seismic zone we would

therefore recommend, after therefractory mortar layer is troweled orhand pargetted on, adding a thin skin(1/16 - 1/8”) of a refractory fabric forwhich there are local suppliers (We canhelp to find one). This “skin” or tentover the dome will keep the sand or grogout should any cracks develop. Such aceramic fiber skin is NOT commonlyused in any French installation we arefamiliar with. The refractory mortarseems to be sufficient to create apermanent skin over the dome in non-seismic conditions.

In a Model 120 installation, welaid down overlapping sheets ofaluminum foil on top of the dome,before adding loose fill vermiculiteinsulation, because we were concernedthat particles might trickle down likesand in an hourglass. We were trying tobe extremely cautious.

In the first Model 120installation outside of Boston, ourmaster oven builder friend, ChristianPozzar, used loose fill mineral wool,


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CHIMNECHIMNECHIMNECHIMNECHIMNEYYYYYSUPPORSUPPORSUPPORSUPPORSUPPORTTTTT

It is notrecommended that a heavymasonry mass be builtresting on any part of themasonry core. Anymasonry chimney builtshould be supported by theveneer walls, not by theoven core. If a short (2' to6') masonry chimney isbuilt directly above the throat andsupported by angle iron and the veneerwalls, a standard clay flue tile 8.5" x 12.5"can be centered over the throat and thenrest on the refractory elements. Flue tilesshould be set with refractory mortar andbe free to move relative to the surroundingmasonry. To protect an outdoor oven’ssole plates beneath the chimney fromfreeze/thaw cycles, the outdoor chimneyshould be fitted with a cap.

The oven floor dimensions for eachmodel are the space required for the ovencore and a thermal mass “insulating” layer ofgrog or sand around the oven. The oven floordimensions do not include space for a masonryshell veneer. If a masonry shell veneer is used, itshould be a minimum of 4" thick with 2" ofclearance to combustibles. If a non-combustible“structural skin” is used instead of masonry, itmust be constructed in such a way that it cancontain any grog or sand fill and any loose fill orblanket insulation you might choose to addoutside of the grog.

roughly 12” thick, as his insulation and didn’thave any additional mass of grog or sand aroundthe oven. The owner reports that his former ovenused to burn a cord of wood each week. The new120 le Panyol had used less than half a cord ofwood after two weeks of use, indicating a 400 %increase in fuel wood savings.



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STONE HEARTHSSTONE HEARTHSSTONE HEARTHSSTONE HEARTHSSTONE HEARTHS

Aesthetics and stone hearth shelfextensions are also explored a bit on the web siteand are in the purview of the owner, baker,architect, mason and designer. We’ll happilyreview any plans or drawings with special detailsof this sort that a client might wish to add orincorporate.

ASH DUMPSASH DUMPSASH DUMPSASH DUMPSASH DUMPS

Ash dump channels on either the large orsmaller models can be easily notched into thefront centered hearth tile of any model or placedin front of the hearth tiles. Dump channels andcovers can be readily fabricated from steel orstainless steel. Cast iron ash dumps are alsoavailable. Ash can be carried to an ash drawer oran easily accessible, properly vented ash pit.Non-combustibility and proper venting of suchan ash pit is essential because live coals stillemitting carbon monoxide, may well be rakedinto the ash pit.

CAPPCAPPCAPPCAPPCAPPING ING ING ING ING YYYYYOUR LE POUR LE POUR LE POUR LE POUR LE PANYANYANYANYANYOLOLOLOLOLOOOOOVENVENVENVENVEN

Caps over the mass can be made out of sheetmetal. Check with local code enforcementofficers for any special requirements the chimneyconnector and chimney must be built to in orderto meet standard chimney codes. There isconsiderable step by step documentation of realworld oven kit and veneer assemblies on theMaine Wood Heat web site(www.mainewoodheat.com).

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Notes

Assembly of the le Panyoloven core: Models 66, 99, and 83

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The Domestic family ofle Panyol oven cores areexceptionally quick and easyto assemble.

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Chapter 4: Assembly of the le Panyol Oven core: models 66, 99, and 83

PPPPPlace the hearlace the hearlace the hearlace the hearlace the hearth tile on a bedth tile on a bedth tile on a bedth tile on a bedth tile on a bedof grof grof grof grof grog or sand and ensurog or sand and ensurog or sand and ensurog or sand and ensurog or sand and ensureeeeethethethethethey ary ary ary ary are leve leve leve leve levelelelelel

Center the oCenter the oCenter the oCenter the oCenter the ovvvvven entren entren entren entren entryyyyyapprapprapprapprapproooooximatly four inches frximatly four inches frximatly four inches frximatly four inches frximatly four inches fromomomomomthe frthe frthe frthe frthe front edge of the hearont edge of the hearont edge of the hearont edge of the hearont edge of the hearth.th.th.th.th.

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For this unique installation of theModel 83 oven the hearth tiles weretrimmed to fit within a modified wagonwheel.

The oven entry is seen in place to theleft of the chimney adaptor madeespecially for the American market.

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www.mainewoodheat.com for the latest step-by-step oven installations.

Chapter 4: Assembly of the le Panyol oven core: models 66, 99, and 83

SSSSStartartartartarting on one side of theting on one side of theting on one side of theting on one side of theting on one side of theooooovvvvven entren entren entren entren entryyyyy, place the, place the, place the, place the, place thevvvvvoussoirs. Soussoirs. Soussoirs. Soussoirs. Soussoirs. Supporupporupporupporupport eacht eacht eacht eacht eachvvvvvoussoir as necessaroussoir as necessaroussoir as necessaroussoir as necessaroussoir as necessary with ay with ay with ay with ay with apiece of wood. Apiece of wood. Apiece of wood. Apiece of wood. Apiece of wood. Adjust bdjust bdjust bdjust bdjust byyyyytapping with a rtapping with a rtapping with a rtapping with a rtapping with a rubber mallet.ubber mallet.ubber mallet.ubber mallet.ubber mallet.

Place metal pins into the holesPlace metal pins into the holesPlace metal pins into the holesPlace metal pins into the holesPlace metal pins into the holesprprprprprooooovided on each side of thevided on each side of thevided on each side of thevided on each side of thevided on each side of theooooovvvvven entren entren entren entren entryyyyy. C. C. C. C. Ciriririrircle the wholecle the wholecle the wholecle the wholecle the wholeooooovvvvven with metal wiren with metal wiren with metal wiren with metal wiren with metal wire ande ande ande ande andsecursecursecursecursecure to each pin. e to each pin. e to each pin. e to each pin. e to each pin. The wirThe wirThe wirThe wirThe wireeeeeshould be snug, but not tight.should be snug, but not tight.should be snug, but not tight.should be snug, but not tight.should be snug, but not tight.

3

Before we made the final assembly weset the oven up on the back of Albie’strailor and scribed a circle on thehearth tiles that when trimmed wouldallow the whole assembly to fit withinthe wagon wheel platform.

4

Masonry screws work best for the pins.Common steel bailing wire works great.The oven will expand when heated andneeds a place to go, so don’t over-tightenthe wire.

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Put the key stone in place.Put the key stone in place.Put the key stone in place.Put the key stone in place.Put the key stone in place.EEEEEnsurnsurnsurnsurnsure that the loe that the loe that the loe that the loe that the lowwwwwer parer parer parer parer part ist ist ist ist isat the same levat the same levat the same levat the same levat the same level as the insideel as the insideel as the insideel as the insideel as the insideof the rof the rof the rof the rof the roof. Coof. Coof. Coof. Coof. Carararararefully adjustefully adjustefully adjustefully adjustefully adjustall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodcircircircircircle inside the ocle inside the ocle inside the ocle inside the ocle inside the ovvvvven.en.en.en.en.

Rob Zajac and Chris are gentlylowering the keystone into its home.

An optional modification that has beenmade by Albie in installations of the Model120, but is not necessary for Models 99and smaller, is to fabricate “stops” for thevoussoirs above the oven entry. They canbe made from light gage steel angles,available at any hardware store, secured inplace with masonry screws. A masonry drillwill also be required for this operation.

Put the key stone in place.Put the key stone in place.Put the key stone in place.Put the key stone in place.Put the key stone in place.EEEEEnsurnsurnsurnsurnsure that the loe that the loe that the loe that the loe that the lowwwwwer parer parer parer parer part ist ist ist ist isat the same levat the same levat the same levat the same levat the same level as the insideel as the insideel as the insideel as the insideel as the insideof the rof the rof the rof the rof the roof. Coof. Coof. Coof. Coof. Carararararefully adjustefully adjustefully adjustefully adjustefully adjustall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodall elements to obtain a goodcircircircircircle inside the ocle inside the ocle inside the ocle inside the ocle inside the ovvvvven.en.en.en.en.

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6

33



Block the assembly byBlock the assembly byBlock the assembly byBlock the assembly byBlock the assembly bytightening the metal wirtightening the metal wirtightening the metal wirtightening the metal wirtightening the metal wire be be be be byyyyyinserinserinserinserinserting pieces of brick orting pieces of brick orting pieces of brick orting pieces of brick orting pieces of brick orstone betwstone betwstone betwstone betwstone between the wireen the wireen the wireen the wireen the wire and thee and thee and thee and thee and thevvvvvoussoirs.oussoirs.oussoirs.oussoirs.oussoirs.

Protect the inside of your ovenProtect the inside of your ovenProtect the inside of your ovenProtect the inside of your ovenProtect the inside of your ovencorcorcorcorcore with paper or plastice with paper or plastice with paper or plastice with paper or plastice with paper or plasticbeforbeforbeforbeforbefore pargetting with thee pargetting with thee pargetting with thee pargetting with thee pargetting with therrrrrefractorefractorefractorefractorefractory mory mory mory mory mortartartartartar.....

7

8

34


Wet the outside of the oven using awatering can or spray-nozzled gardenhose making sure all joints arethoroughly wet.

Take 1/4 of the refractory mortar from thebag provided with the oven kit and mix justenough water to create a thin paste. Pourthis around the keystone and down alongthe joints make sure all opening have beensealed.

9

10

Albie is begining to fill the joints

35



With the remaining portion of therefractory mortar, mix enough water tocreate a slighly thicker mixture thanbefore and spread by rubber glovedhand, starting from the bottom, tocomplete the installation of the oven.

You have completed the assembly of yourle Panyol Oven core. LEAVE IT TODRY FOR THREE WEEKS,PROTECTED FROM BELOWFREEZING TEMPERATURES.

12

11

Avoid contact with the refractorymortar or any cement based product asthey are caustic and can cause damageto the skin. Chris has chosen to use atrowel to spread the mortar.

Information on building the oven veneer anddimensions can be found starting on page 19.

36


Model 66: Front Section

Model 66: Side Section

Model 66: Plan

37





Model 99: Plan

38



Model 83: Plan

39




40

Notes

3Assembly of the le Panyol Oven core:

Models 120 and 1805

41

Chapter 5: Assembly of the le Panyol Oven core: models 120 and 180

42

INTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTIONINTRODUCTION

The 120 and 180 are made from thesame Terre Blanch (white earth) as thesmaller model (66, 99 & 83) and follow thesame classic French round oven design, butthe larger ovens have larger chambers andthicker walls. Instead of single voussoirelements that reach from floor to capstone,the professional model voussoir elements aredivided into stacking tapered tongue andgroove segments. The model 120 has threestacking tongue and groove segments in eachvoussoir and the model 180 has four stackingtongue and groove segments in eachvoussoir. This allows each element to bemanufactured and handled in the factory, aswell as in the field installation by oneperson. Each element also has very slightfreedom of movement from every otherelement, so while the combined system has avery stable form, the system also has built inflexibility and great ability to absorbdifferential heat expansion and minormovement.

From the center point of the centertile of each hearth assembly, a large compass(or anchored string and pencil) can scribeboth the inside and outside diameters of theoven base course on the hearth assembly (#120 47 1/4" i.d., 59" o.d.) (#180 70 7/8" i.d.,82 5/8 o.d.). A plastic sheet the diameter ofthe inner diameter of the oven is laid atopthe scribed inner circle.

SUPPORSUPPORSUPPORSUPPORSUPPORTING TING TING TING TING THE THE THE THE THE VVVVVOUSSOIROUSSOIROUSSOIROUSSOIROUSSOIRSECTIONS DURINGSECTIONS DURINGSECTIONS DURINGSECTIONS DURINGSECTIONS DURINGCCCCCONSTRONSTRONSTRONSTRONSTRUCTIONUCTIONUCTIONUCTIONUCTION

Traditional French ovens were laid up courseby course with brick, stone or firebrick on awet sand or wet clay-sand dome, which couldbe shaped to a moveable convex templatematching the inside curve of the intendedoven dome.

Le Panyol oven core kits, because theyare already formed, only need to besupported under each voussoir section asthey go together. A cardboard template isprovided with each oven that matches theinside curve of each oven model. Using thetemplate, the oven builders or builder/buyercan cut 1/2" plywood replicas of this pattern.The model 120 requires 18 plywood “ribs”,cut to match its pattern, whereas the model180 requires 22 ribs, cut to fit it’s uniquepattern. The three ribs for each oven that fitover the door lintel have to be additionallynotched where they rise past the inside ofthe door opening lintel. This can be doneeasily on site with trial and error cutting andplacement of these three notched “ribs”.

Early le Panyol oven kit assemblieswere accomplished using ribs and a woodenpost against which the ribs could lean. Allwere burned out during the first fire. Morerecently, this system has been improved bycreating similar ribs that slot onto a circularplywood disc with u-shaped metal channelsmounted atop a simple scissors jack (cf.www.mainewoodheat.com, chatfield #120oven)

The jack is placed on an 18" x 36"piece of plywood (to distribute the weight

Typical rib (left), Notched rib to accept oven entry (right).

Chapter 5: Assembly of the le Panyol oven core: models 120 and 180

43www.mainewoodheat.com for the latest step-by-step oven installations.

over several hearth tiles) and both the jackand plywood weight distributor are centeredover the middle tile. Each of the ribs (120 =18)(180 = 22) is eventually placed in theplywood disc and channels with the base ofeach rib just touching the inside diametercircle scribed on the oven tile hearth floor.The three elements opposite the arch lintelelements must be notched to fit the back sideof the arch lintel elements. The back (notfront) outside corners of each arch lintelelement should touch the scribed innerdiameter dome circle. All of the base courseelements are equal and can be set on bothsides of the arch lintel elements followingthe inside scribed circle. Once the firstcourse of elements is set and tapped with arubber mallet snugly into position, a pair oftap con screws, 2 1/2" - 3" long can be set inthe lower exposed side faces of the arch lintelelements, and to these screws a double ortriple strand of tie wire (3/32") can beattached, binding the base course into placeall the way around the base.

Once the base course is in, theplywood ribs can be carefully placed and thejack post raised, lowered, or centered asnecessary. The ribs behind the arch elementscan be notched to fit the back side of theelements.

For the model 120, courses two andthree can be dry stacked and rapidly laid,

with each piece resting on a centeredplywood rib. For model 180, a fourth courseof voussoir sections is laid, then either modelis ready to receive its respective keystone.

It may be helpful to leave out thethree sets of voussoirs over the arch linteluntil the keystone conical plugs are set.Leaving out these over-lintel sections allowsone to more easily see the space and fit beingcreated for the cone section keystone. Oncethe keystone is snugly in position, then theover-lintel voussoir sections can be easily laidinto place. Because these sections do notcontinue directly to the oven floor, there is ahigher likelihood that lateral thrust willslide their bases out over towards the outerface of the lintel stones and away from thecone section keystone at the top. To ensurethat those voussoir sections do not slide, it ispossible to cut short lengths, 5-7" ofgalvanized slotted angle iron, 3/32" x 1/8" x1 1/2", which when slid under the bottomedge of each of these partial voussoir

Modified scissor jack .

3 angle irons fabricated to secure the voussoirs abovethe oven entry. (top), Angle irons in place and securedwith masonry screws. (above)


44

sections, can be anchored securely with twotap con screws, each, drilled into the lintelelements.

APPLAPPLAPPLAPPLAPPLYING YING YING YING YING THE REFRATHE REFRATHE REFRATHE REFRATHE REFRACACACACACATTTTTORORORORORYYYYYMORMORMORMORMORTTTTTARARARARAR

The refractory mortar covering overthe whole dome is the traditional way ofsecuring the whole assembly, but thesesimple slotted angle iron sections are aninsurance policy against any slippage on thethree partial voussoir sections.

At the outside base of the domeelements of each of the larger models, werecommend that a small dike of relativelystiff Fayol refractory mortar be placed as a“collar” to assure the dome of stability andvery limited movement at its base. Oncethis modest collar is troweled down, then athinner paste of the mortar can be drooledon, and into, each seam and then the entiremass is covered with a thin coat of themortar.

With the refractory mortar skin on,the factory oven core kit is complete, but thefull oven assembly is not.

CURINGCURINGCURINGCURINGCURING

Once up the exterior of the oven should beparged with a loose mix of Fayol 1,100Mortar. This will fill any large jointsbetween the voussoirs. One bag of Fayol1,100 mortar should be mixed with 4 litersof water. The exterior of the vault should bewet slightly before pargetting, to preventthe mortar drying out too fast. Theremaining mortar can be hand applied(rubber gloved) to the exterior of the vault.Allow the oven to dry for three weeks. (donot allow to freeze duringthis time).

Make a series of small fires to cure the oven.

ADDITIONAL MASSADDITIONAL MASSADDITIONAL MASSADDITIONAL MASSADDITIONAL MASS

For the 120 and 180 models werecommend adding an additional layer ofmass around the dome. The advantage ofadditional mass is an extended baking timebetween firings. See page 25 for designconsiderationsRefractory “collar”

Completed oven core kit with optional additional masswaiting for the veneer to be completed.



Notes


46

Model 120: Plan






48

Model 180: Plan





50

Notes

Appendixes A

51

MO

DE

L66

9983

120

180

WE

IGH

T82

5 lb

s.11

00 l

bs

1188

lbs

2420

lbs

4620

lbs

(375

kg.)

(500

kg.)

(540

kg.)

(110

0 kg.)

(210

0 kg.)

TIL

E L

AY

OU

T3

wid

e x 3

dee

p3

wid

e x 4

dee

p4

wid

e x 4

dee

p5

wid

e x 5

dee

p7

wid

e x 7

dee

p

HE

AR

TH

TIL

E39

3/8

" x 3

0 3/

8"39

3/8

" x 5

2 1/

2"52

1/2

" x 5

2 1/

2"65

" x 6

5"90

1/2

" x 9

0 1/

2"

DIM

EN

SIO

NS

(1 m

x 1

m)

(1m

x 1

.30m

)(1

.30m

x 1

.30m

)(1

.65m

x 1

.65m

)(2

.30m

x 2

.30m

)

HE

AR

TH

TIL

E2-

1/2”

2-1/

2”2-

1/2”

2-1/

2”2-

1/2”

TH

ICK

NE

SS

(63

mm

)(6

3 m

m)

(63

mm

)(6

3 m

m)

(63

mm

)

INSU

LA

TIN

G S

LA

B3"

th

ick x

sam

e3"

th

ick x

sam

e3"

th

ick x

sam

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-6"

thic

k x

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-6"

thic

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wid

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nd d

epth

wid

th a

nd d

epth

wid

th a

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th a

nd d

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th a

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TO

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OR

E19

5/8

"19

5/8

"19

5/8

"26

"29

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”

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IGH

T(5

0 cm

)(5

0 cm

)(5

0 cm

)(6

6 cm

)(7

4.8

cm)

INSID

E H

EIG

HT

12-3

/4"

12-3

/4”

12-3

/4"

17 5

/16"

20 7

/8"

(32.

5 cm

)(3

2.5

cm)

(32.

5 cm

)(4

4 cm

)(5

3 cm

)

CO

OK

ING

SU

RF

AC

E3.

68 s

q/f

t6.

3 sq

/ft

5.8

sq/f

t12

.09

sq/f

t27

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q/f

t

(0.3

5 sq

/m)

(0.5

6 sq

/m)

(0.5

4 sq

/m)

(1.1

3 sq

/m)

(2.5

4 sq

/m)

WA

LL

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SS

4 1/

2"4

1/2"

4 1/

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1/8”

6-1/

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(11.

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(11.

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cm)

(15.

5 cm

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DO

OR

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ING

13 3

/4"

x 7

7/8

"13

3/4

" x 7

7/8

"13

3/4

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7/8

"10

1/4

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1 1/

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3/8

" x 2

5 3/

13"

(35c

m x

20c

m)

(35c

m x

20c

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(35c

m x

20c

m)

(26c

m x

54c

m)

(34c

m x

64c

m)

52

2004 Addendum

Ash Dump, Dampers and Chimney Caps

An indoor oven should include an ash dump. When cooking pizza or otherlive flame foods, no raking out of coals is required, but when preparingto bake bread, ashes and some small live coals will need to be raked outat the end of a burn.

The hearth is then further swept and swabbed with a wet cloth or mop.

Pivoting ash dumps made of cast iron, approximately 9" x 4.5", arereadily available at building supply yards. These dumps are usuallyplaced in front of the oven door beneath the throat. A knockout form forthe ash dump can be made for the concrete slab with pieces of styrofoam,duct taped together and perhaps with a cedar shingle spacer in the center.

When laying the thermal block insulating layer, cut out a 4.5" x 9" holealigned with the hole in the concrete slab. Calculate the exact heightof the hearth and lay up a thin mortared level dike wall of firebrick,ytong, or common brick strips around the hole. This will keep the groglayer underneath the hearth from spilling into the hole.

Grog is then filled to the height of the “dike” around the hole and thebalance of the hearth tiles are laid and leveled on the grog. The tilesaround the ash dump should be carefully cut to receive the ash dump rimso that it lays level with the hearth floor. The ash dump can be set inusing refractory mortar.

An outdoor oven installation is less in need of an ash dump, but it canstill be useful. The ashes should dump out in an airtight, fireproofspace, such as the hollow core of the foundation or base of the oven andbe accessible with a clean out door.

53

2004 Addendum

Damper

Outdoor ovens do not require a chimney damper, but will benefit from achimney cap. The terre blanche hearth tiles (especially at the dooropening) and oven core must be protected at all times from moisture fromrain or snow. If the tiles get overly wet in the winter, frost can getinto the tiles and cause them to crack. If the tiles are saturated inany weather, a hot fire can cause thermal shock from steam expansion.Protect your hearth and dome by creating a waterproof roof for the ovenand a cap for the chimney.

An indoor oven benefits greatly from a damper in order to assist in draftregulation, but also to avoid heat loss when the oven is not in use.When using an 8" round pipe exhaust, there are three readily availabledamper solutions. One is to use a standard cast iron pivoting stove pipedamper. Some air will still escape past this damper, but fully closed,it will greatly reduce air flow and heat loss up the chimney.

A custom made solid damper can also be fabricated by the MWH Co. oranother fabricator. A second option is an airtight spring loaded chimneytop damper. These are usually cast aluminum and are fitted to thechimney flue tile at the top of the chimney. They double as a cap devicefor the flue and will keep water out of the flue and off the hearth.They are operated by a stainless steel cable, which snakes down throughthe flue liner and/or can be sleeved out through a metal tube near theoven throat to a lever handle or can be mounted to the inside of thethroat wall. Custom handles can be fabricated if the factory handle isnot aesthetically pleasing.

A third option is to fabricate a second light weight door with a gasketedlip that is slightly larger than the factory supplied bake oven door.The oven door lips against the inner arch elements. A second door canlip against the outer arch elements effectively sealing off the chimney.

The Maine Wood Heat Co., Inc. can assist in the location of supplies of

any of the above mentioned components.

Documents

Bread Oven