Masonry Heaters, Wood-Fired Ovens, Natural Building

Bali Wood-Fired Oven

We built this wood-fired oven in Bali for Max’s parents using local bricks, clays, sands and fibers. The oven joins the traditional paon (cookstove) that Max built a few years ago.

This oven features ample wood storage for both units, a metal firing door and a wooden door for baking. (Stay tuned for an article about firing doors and efficiency in wood-fired ovens.)

It is always a fun challenge to apply our knowledge of ovens and natural building to local materials. The clay for this oven comes from a village roof tile factory scrap pile and the sand and stone came from a nearby volcano. We found an incredibly porous lava stone to insulate underneath the hearth floor and surrounded the oven’s thermal layer with a mixture that included rice hulls and thatching grass.

Note the sand used to make the smooth inside shape and the sculpted “squirrel tail” to jog the chimney. Upon finishing the oven, we cooked for a three day “Live-Culture Cuisine” fermentation workshop led by Sandor Katz and Mary Jane Edleson.

Many delicious feasts ahead!

Learn to Build Your Own Earth Oven!

Ledge Stone Masonry Heater Near Eugene, Oregon

This heater was built for a family who live near Eugene, OR.  It features a see-through firebox, heated bench and a bake oven.  The outside skin is laid with Montana Bitterroot ledge stone with Three Rivers stone detailing the bake oven arch.  We cast, poured and and polished the bench which includes special embedded stones and fossils.

The heater has a compact, responsive design which serves as a partial wall between living and dining room spaces.  It could have many different facing looks, occupies an area of 48″ x 48″ and stands 6 1/2′ tall.

Read More….

Thanks to Greenleaf Design Build for their good organization and excellent
craftsmanship which allowed our work to flow together seamlessly with their’s.

Masonry Heater at the Allen’s (Portland, OR)


We built this masonry heater in the Portland area in autumn of 2011.  Our clients had collected many beautiful bricks dating back to 1883 (a long time from our West Coast perspective!), local basalt rock, and cobble stones that originally paved the streets of Portland.

This masonry heater (based on the Swedish 5-run design) has a see through firebox, a bake oven, a three-sided heated bench, and a place for wood storage.

This project brings together our understanding of the technical aspects of combustion and heating efficiency and our experience with design and use of recycled building materials.  The heater is currently curing and the exit flue will be installed shortly.  We plan to update this post once the heater is fired and make new posts about the process of this build and about the use of polished “concrete counter tops” for benches and other elements of mass heaters.  Check back on this site, join our mailing list, and see more about this project on Facebook.

Thank you to Norbert Senf and Doug Hargrave for their development of the Norccore and for generous technical assistance in preparation for this project.  Thank you also to Jerry Frisch for continual support and inspiration.

Read more….

Pizza Party in the Dabbeni Barrel Oven!



This Barrel Oven’s maiden voyage fed over 70 people with amazing pizzas!

The pizza above is one of Astrid’s special recipe- corn, mozzarella and gorgonzola.
Once out of the oven it is topped with arugula and white truffle oil.
Another pizza sauce was made with capers from Paolo’s mother’s garden in Italy.



I made chocolate truffle brownies and gingerbread cake for dessert!


During the party we cooked some pizzas directly on the
pizza stones and some on metal pans.
The pizzas cooked on the stones had a more crispy and delicious crust.
Above you can see the barrel oven with plaster still drying.

Read More

Written by in: Latest News,Recent |

MHA Announces New Masonry Heater Education Program

Tucson, Arizona, July 28, 2011

The Masonry Heater Association of North America has recently developed the HMED (Heater Mason’s Education & Development) program designed for masons and people interested in learning how to build wood-fired masonry heaters.

The program is designed to:

  • Provide an education program that starts with basic information and skills training.
  • Provide a standard curriculum that will be delivered in facilities throughout North America.
  • Provide opportunities to earn continued education credits for various certification programs.
  • Promote safe building practices for everyone interested in building masonry heaters.
  • Establish a training system that is specific to North America.

MHA’s HMED program provides an excellent opportunity for someone to learn the basic theory and construction of masonry heater, a necessary step before taking on the task of building masonry heaters. The program was developed due to increasing interest in Masonry Heaters as an alternative method to heat homes.

Classes are currently scheduled for:

September 17 – 20, 2011 in Perth, Ontario, Canada, level one, modules 1 &2
November 04 – 07, 2011 in Shutesbury, Massachusetts, level one, modules 1 &2


September 17 – 20, 2011 in Perth, Ontario
$399/module for MHA members
$450/module for non MHA members

November 4 – 7, 2011 in Shaftesbury, Massachusetts
$399/module for MHA members
$450/module for non MHA members
$500 room and meals at Sirius Community

What are Masonry Heaters?

A masonry heater is a special type of fireplace made of stone, brick, stucco or tile which will heat your home safely and comfortably. Masonry heaters burn wood, which is North America’s cheapest and most abundant bio-fuel. We currently use less than ten percent of available deadfall timber from our forests. Masonry heaters burn efficiently and with very low emissions, which make them extremely “green”.

Masonry heaters work on the principal of thermal storage due to the considerable thermal mass of the materials used in their construction (most of them are heavy, often weighing tons). The best masonry heaters soak up most of the heat from the wood blaze within the firebox through a cleverly designed system of channels or chambers which “harvest” heat from the hot gases as they pass by. This energy migrates through the masonry slowly until it reaches the surface where it “illuminates” the room with invisible rays of heat known as infrared radiation. This way heat from a fire in the morning can still be warming a home in the evening.

The Masonry Heater Association of North America hosts an annual workshop where masons can get hands-on practice building wood-fired masonry heaters and bake ovens. Instructional books on how to build and operate masonry heaters and bake ovens are available on the MHA’s website.

For more information on masonry heaters, education classes or membership in the Masonry Heater Association of
North America, contact the MHA office:

Masonry Heater Association of North America
Richard Smith, Executive Director
2180 S. Flying Q Lane
Tucson, AZ. 85713
(520) 883-0191

Find out more…..

Written by in: Latest News |

Outdoor Kitchen at Vistara: Wood-Fired Barrel Oven and Canning Stove

Ever dreamed of an efficient earthen oven that was hot in just 15 minutes?
How about a canning stove that could process 32 quart jars at once?


The new Wood-Fired Barrel Oven and Canning stove at Vistara!
Built with students during the Outdoor Kitchen Workshop Series!

These two cooking devices will soon be part of a full kitchen with shelving, a sink, wood-storage and more!  They will be connected by counter tops and sheltered by a roof providing ample space to prep and to gather. This will be a resource for the local community!

Vistara has a beautiful garden and many neighborhood fruit trees from which to harvest abundant produce to preserve.  The wood-fired canner is quick to heat up and can also double as a soup pot, stew pot, sauce pot, steamer, etc. Both the barrel oven and the canner were constructed with homemade adobe bricks and plaster formed with Vistara’s clay rich soil.  Thank you to our hosts and the amazing team that helped make this happen!

 Find out more about The Wood-Fired Barrel Oven.

Complete Cob Workshop at Cob Cottage Company – Bandon

Jun 11-19, 2011 in Bandon OR

Max & Eva taught a 9 day intensive course called Complete Cob.

Our project was to build a pavillion that is a large part of a budding outdoor kitchen at the home of Bob and Tammy Van.  During the nine days, we sculpted this structure with local soil, driftwood, redwood and found windows. The course covered in depth all aspects of cob and building techniques such as foundations, construction of walls, arches for doors and windows, roofing, plumbing, electric, shelving, furniture, earthen floors, artistic details and finish work.  In addition to the outdoor kitchen, Bob and Tammy wanted to renovate their garage into a meeting place and so we also worked with them to remodel their existing stick frame construction with ladder trusses and the participants mixed and installed light straw clay insulation.

Added bonuses were the rumford fireplace we built in the pavillion and plastering the new Cob Masonry Heater at Cob Cottage Company!  Our course also covered general natural building strategies such as siting and passive solar design.  We had a beautiful time and are so thankful to our generous and talented hosts!

Making the model

Building and Carving

Windows and Arches

Shelves and Chiseling

Ridge Beams, Rafters and Lashing

Making a Rumford and an Earthen Plaster on the Cob Cottage Masonry Heater

Making a Beautiful Outdoor Kitchen!

The Cob Pavillion with Rumford Fireplace

More photos of the finished roof, plaster and the straw clay retrofit coming soon…

Written by in: Latest News,Natural building |

Straw Clay Retrofit – Village Building Convergence 2011

This year at the VBC,
Eva led the second phase of a light straw clay retrofit in SE Portland
at the Planet Repair Institute!

Light Straw Clay technology has been used for centuries!
People love the low cost, low toxicity, and its use of sustainable, native and locally available materials!

Over a ten day period, with hands on learning, I taught students how to make and use straw-clay effectively and efficiently to build insulated walls.  (See also last year’s post.)

Participants learned about Larson truss framing, and the many facets of mixing and installing straw clay and cob for both interior and exterior settings. We all enjoyed the incredible benefits of this natural building technique as we retrofitted a previously poorly insulated Portland home! I returned later with students to put a base coat plaster on all the walls. Next year at the VBC I will lead the finish plaster, aliz, and sculptural details on this project with Molly Murphy of the Mud Girls.

And good news!  Light straw clay has now been approved by the City of Portland!  This is Portland’s pilot project!  Click here to see the info from ATAC about permitting this technique...

More about the Village Building Convergence…
More about the Planet Repair Institute…

Join our mailing list to receive updates about the finish plaster and more!

Written by in: Latest News,Natural building |

Cob Masonry Heater at Cob Cottage Company

cob masonry heater group

This is a very exciting and experimental masonry heater built by many hands through a workshop at the Cob Cottage Company in southwestern Oregon.  The challenge – that Ianto Evans is so consistently a champion of – was to build a masonry heater that was made of local materials and through local craftsmanship.  Flemming Abrahamsson, master mason and incredible human being, traveled from Denmark to guide us in the work based on his decades of experience as a heater builder in Europe.  The inside of the heater is based on a Swedish 5-run design.  It is a single-skinned heater which has a firebrick core and is faced with recycled brick set in a clay-based mortar from clay dug on site and cob.  The hardware for the heater was fabricated by Max – his first arched glass door!
The plaster and paint were made and applied during a class taught by Eva Edleson and Jo Forsyth during the Complete Cob Course.

Jon Santiago, one of the participants in the course, documented the build wonderfully in this Facebook album.  For those interested in how it was built, it is worth zooming in on each photo.

Join our mailing list for updates about it how it fires and performance through the winter.

Further reading…..

Firespeaking - 91040 Nelson Mountain Rd., Deadwood, OR 97430 - info (at) - (541) 964-3536 - OR CCB# 200122