By Eric Moshier — Certified Heater Mason (MHA), ASTM E1602 Committee Member, Solid Rock Masonry LLC | Duluth, MN
- Custom masonry heaters are site-built, high-efficiency wood heating systems that store heat in thermal mass and radiate warmth for 12 to 24 hours after a single fire.
- Solid Rock Masonry builds three styles: Finnish Contraflow, Russian Bell, and Swedish 5-Run — finished in brick, stone, soapstone tile, or plaster.
- Site-built custom heaters range from $20,000 to $40,000 depending on size, style, finish material, and travel distance.
- Eric Moshier is a Certified Heater Mason (MHA) and ASTM E1602 committee member with 25+ years of experience and hundreds of completed projects.
- Masonry heaters operate without electricity, last 50 to 100 years, and are 80 to 90 percent thermally efficient.
- Primary service area: Upper Midwest. DIY kits ship nationwide starting at $5,000.
Custom masonry heaters from Solid Rock Masonry are site-built for homes across the Upper Midwest by Eric Moshier — a Certified Heater Mason, ASTM E1602 committee member, and founder of the SR Core system, with 25+ years of experience and hundreds of completed projects.
Site-built custom heaters run $20,000 to $40,000 depending on size, style, and design complexity. We build three core styles: Finnish Contraflow, Russian Bell, and Swedish 5-Run. Every heater is custom-designed for your home and climate.
This page covers how masonry heaters work, the three styles we build, typical pricing, what is included in a custom build, and what to expect from our process. If you are ready to talk, contact us for a free consultation.
How Does a Masonry Heater Work?
A masonry heater works by burning one or two short, hot fires per day. Then storing that heat in hundreds of pounds of thermal mass and releasing it slowly and evenly for 12 to 24 hours. This is fundamentally different from a wood stove or fireplace, which radiates heat only while burning.
The combustion gases travel through a series of internal channels inside the heater body. Additionally, those channels extract as much heat as possible before the gases exit through the flue. By the time flue gases leave a properly built masonry heater, they have cooled to approximately 300 to 350 degrees F, compared to 500 to 700 degrees F for a conventional wood stove.
The result is a heating system that is 80 to 85 percent thermally efficient. For context, a standard open fireplace operates at negative efficiency — meaning it draws more heat from the room than it produces. Masonry heaters, however, achieve some of the highest efficiency ratings of any solid-fuel heating system available.
Because masonry heaters operate without electricity, they work during power outages. Furthermore, when properly built and maintained, they last 50 to 100 years.
What Styles of Masonry Heaters Do You Build?
We build three primary masonry heater styles, each with a distinct flue gas path, heat distribution pattern, and aesthetic:
| Style | Flue Path | Best For | Footprint |
| Finnish Contraflow | Gases are directed up through or around the bake oven. Then descend down the right and left contraflow channel before exiting into the chimney or through heated benches. Chimney exit is always on the bottom of the core. | Large to small homes. Adding heated benches on 1 to 3 sides will maximize the efficiency. | Larger with side chimney and heated benches |
| Russian Bell | Gases exit firebox into a 1-3 bell chambers, and or a bake oven. Then descend to the exit flue. | Larger or small homes. Adding heated benches on 1 to 3 sides will maximize the efficiency. Bake oven can be on the front, back or side of the unit. | Compact to Larger depending on the design and heating needs. |
| Swedish 5-Run | Five distinct flue channels distribute heat throughout the heater body. Chimney will exit out the top of the heater. | This is our most compact design with the chimney exiting out the top. Classic Scandinavian design with proven long-term performance. | Moderate |
Finnish Contraflow
The Finnish Contraflow is the most popular style we build in North America. Flue gases travel down through a contraflow channel before exiting — therefore maximizing heat extraction from every fire. This design has a compact footprint, well-suited for most residential living rooms and great rooms. It is a strong choice for first-time masonry heater owners who want proven performance in a practical package. The standard unit has the chimney connected on the side. Adding on a heated bench on 1 to 3 sides will maximize the efficiency for larger homes. A bake oven can be added onto the front or the back side of the unit.
Russian Bell
In a Russian Bell, heat rises naturally into a large bell chamber. There, the gases dwell and transfer into the surrounding mass before cooling and descending to the exit flue. As a result, this style is extremely efficient and well-suited to larger homes and colder climates. However, the Russian Bell requires a larger footprint and careful structural planning. Russian Bell heaters can be designed in a number of shapes and sizes with bake ovens and heated benches added onto them. This design also makes a side bake oven optional for some house designs.
Swedish 5-Run
The Swedish 5-Run features five distinct flue channels, which distribute heat evenly throughout the heater body. This is a classic Scandinavian design with a long track record of performance. Consequently, it is a strong choice for clients who want a time-tested design with excellent heat distribution and traditional aesthetic appeal.
All three styles can be finished in brick, natural stone, soapstone tile, or plaster. In addition, each can be integrated with heated benches, bakeovens, woodboxes, and custom decorative facing.
What Does a Custom Masonry Heater Cost?
Custom masonry heater pricing ranges from $20,000 to $40,000 for a site-built installation, depending on size, style, finish materials, and travel distance:
| Configuration | Approximate Price Range |
| Standard custom build — brick or plaster finish | $20,000 to $28,000 |
| Custom build with natural stone facing | $25,000 to $35,000 |
| Custom build with heated bench or bake oven | $30,000 to $40,000 |
What affects price most: Size and mass, finish material, optional features (bench, bake oven, woodbox), and travel distance from Duluth, MN.
What is not included: Foundation and chimney are quoted separately. Typical chimney systems run $3,000 to $6,000 depending on height and configuration. Normal foundations run $4,000 to $8,000.
If you want to explore a lower price point, our SR Core DIY Masonry Heater Kits start at $5,000 and ship to all lower 48 states and Canada.
What’s Included in a Custom Build?
Every site-built custom masonry heater from Solid Rock Masonry includes:
- Full design consultation and heat-load review for your home and climate
- Engineering-based sizing for your space
- Written foundation specification for your contractor to pour before we arrive
- SR Core refractory firebox system — manufactured by Solid Rock Masonry in Duluth, MN
- Complete masonry shell in your choice of finish material: brick, stone, soapstone tile, or plaster
- Door and draft hardware
- Chimney connection coordination
- On-site commissioning — we walk you through proper firing procedure before we leave
Optional additions: Heated bench, bake oven, woodbox, custom stone or tile facing, and integration with existing architecture.
As a Certified Heater Mason and ASTM E1602 committee member, Eric builds to the ASTM E1602 construction standard. All builds comply with IRC Section R1002. Learn more: solidrockmasonry.com/masonry-heater-building-codes/
Where Do You Build Masonry Heaters?
Our primary service area is the Upper Midwest: Minnesota, Wisconsin, Upper Peninsula of Michigan, Iowa, the Dakotas, and surrounding states. However, we consider travel projects nationwide for larger builds.
Local clients in the Duluth/Superior metro, Iron Range, Ely, and the BWCA corridor benefit from shorter lead times and lower travel costs. In addition, we have completed builds throughout northern Minnesota, Michigans Upper Peninsula, the Twin Cities metro, and northwestern Wisconsin.
DIY kits ship nationwide: SR Core DIY Kits start at $5,000 and ship to all lower 48 states and Canada. See: solidrockmasonry.com/solid-rock-diy-masonry-heater-kits/
How Does the Build Process Work?
Here is what to expect from start to finish:
- Consultation: Phone or video call to discuss your home, heating goals, and budget.
- Design and Quote: We size the heater for your space and provide a detailed written estimate with scope, pricing, and timeline.
- Scheduling: Builds are scheduled seasonally. Spring and fall are typically our busiest periods.
- Foundation: You or your contractor pours the foundation to our written spec before we arrive.
- Masonry heater on site construction typically takes 3 to 5 days depending on size and complexity.
- Commissioning: We walk you through proper firing procedure, drying-out protocol, and maintenance before we leave.
- ***NEED TO add on the heater planning guid and link****
Most projects from first contact to completed build take 3 to 6 months, depending on scheduling and foundation work on your end.
Related Products
In addition to custom site-built heaters, Solid Rock Masonry offers masonry heating products that ship nationwide:
- Tulikivi Soapstone Heaters: Pre-engineered soapstone masonry heaters from Finland — designed, supplied, and installed by Solid Rock Masonry. See: solidrockmasonry.com/tulikivi-soapstone-radiant-fireplaces/
- SR Core DIY Masonry Heater Kits: Complete kit starting at $5,000, ships to all lower 48 states and Canada. Three build options by skill level. See: solidrockmasonry.com/solid-rock-diy-masonry-heater-kits/
- Solid Rock Masonry Heater Doors: Custom fabricated in Duluth, MN. North American steel, pyroceramic glass, fully gasketed. Ships nationwide. See: solidrockmasonry.com/solid-rock-doors/
Project Portfolio — Browse Our Work
We have built hundreds of masonry heaters in a wide range of styles and finishes. Browse completed project photos by finish type:
| Stone Masonry Heaters | solidrockmasonry.com/stone-masonry-heater-gallery/ Heaters finished in granite fieldstone, taconite, limestone, ledgestone, and northern Minnesota local stone |
| Stone Masonry Heaters 2 | Stone masonry heaters of all shapes, sizes and designs. |
| Brick Masonry Heaters | solidrockmasonry.com/category/brick-masonry-heater/ Heaters finished in clay brick, reclaimed brick, and brick-and-limestone combinations |
| Stucco and Plaster Heaters | solidrockmasonry.com/gallery/stucco-masonry-heaters/ Heaters finished in lime plaster, clay plaster, and stucco — including modern Grundofen-style designs |
| Masonry Heater Doors | solidrockmasonry.com/gallery/masonry-heater-doors/ SR door designs installed on completed heater projects |
| Full Project Gallery | solidrockmasonry.com/gallery/ Complete photo gallery of all Solid Rock Masonry projects by service type |
Additional project write-ups and build documentation are available at: solidrockmasonry.com/news/
Frequently Asked Questions
How long does a custom masonry heater last?
A properly built masonry heater with quality refractory materials will last 50 to 100 years. The SR Core firebox is specifically engineered for this lifespan. Routine maintenance — primarily cleaning the flue annually and inspecting door gaskets — is all that is required to maintain performance over decades.
How much wood does a masonry heater use per season?
A well-insulated Minnesota home typically requires 3 to 4 full logger cords of wood per heating season with a masonry heater, depending on winter severity and the size of the space being heated. That is significantly less than most conventional wood stoves require for equivalent heat output.
Does a masonry heater require electricity?
No. A masonry heater operates entirely without electricity — there is no blower, thermostat, igniter, or control system. This makes it one of the few heating systems that continues to function reliably during power outages, which is a significant advantage in northern Minnesota winters.
Can I add a bake oven or heated bench?
Yes. Both are common additions and are designed into the heater from the beginning. A bake oven integrates into the firebox heat path. A heated bench extends the thermal mass and provides a warm surface for sitting or sleeping. Both additions fall in the $30,000 to $40,000 build range.
What is the difference between a masonry heater and a wood stove?
A wood stove radiates heat only while it is actively burning. A masonry heater stores combustion heat in thousands of pounds of mass and releases it over 12 to 24 hours from a single firing. Masonry heaters are 80 to 85 percent thermally efficient; most wood stoves range from 60 to 75 percent.
What is the difference between a masonry heater and an open fireplace?
An open fireplace typically operates at 0 to 15 percent efficiency — and some run negative efficiency, drawing more heated room air up the chimney than they contribute. A masonry heater achieves 80 to 90 percent efficiency by capturing nearly all combustion heat in its mass before gases exit.
What foundation does a masonry heater require?
A typical spec calls for 4,500 PSI concrete at a minimum of 8 inches deep, with one-half inch rebar on 12-inch centers. Solid Rock Masonry provides a written foundation specification for your contractor before scheduling so the pour can be completed well in advance of our arrival.
Are masonry heaters EPA certified?
Masonry heaters built to ASTM E1602 standards are exempt from EPA wood heater certification requirements under 40 CFR Part 60, Subpart AAA. Eric Moshier serves on the ASTM E1602 committee that writes and maintains this standard. Learn more: solidrockmasonry.com/masonry-heater-building-codes/***FIND THIS ARTICLE ANDS Publish link and add this link. you wrote it
How do I know what size masonry heater I need?
Masonry heater sizing depends on your heated square footage, insulation quality, ceiling height, climate zone, and whether the heater will serve as primary or supplemental heat. We calculate this during the design consultation and size the heater accordingly. **ADD planning guide link
Do you offer financing?
We do not offer in-house financing, but many clients use home equity lines of credit or construction loans for masonry heater projects. A masonry heater is a permanent structural addition to your home, which makes it a reasonable candidate for that type of financing.*** Change this to the new QB FINANCINGF OPTion.
Ready to Build Your Masonry Heater?
Custom masonry heater projects start with a conversation. Tell us about your home, your heating goals, and your location — and we will tell you what makes sense.
Eric Moshier — Solid Rock Masonry LLC
Phone: 218-343-2978
Email: eric@solidrockmasonry.com
Location: Duluth, MN — Serving the Upper Midwest
Contact Us to Get Started: solidrockmasonry.com/contact-us/
Also considering a DIY kit? SR Core kits ship nationwide starting at $5,000. See: solidrockmasonry.com/solid-rock-diy-masonry-heater-kits/
Disclaimer: Masonry heater pricing and specifications vary by project. All estimates are provided after a design consultation and site assessment. Building codes and clearance requirements vary by jurisdiction.About the author: Eric Moshier is a Certified Heater Mason (MHA), ASTM E1602 committee member, and founder of Solid Rock Masonry LLC in Duluth, Minnesota. He has designed and built masonry heaters throughout the Upper Midwest for 25+ years and manufactures SR DIY masonry heater kits. Eric is a Master Stonemason and Master Stove Builder who can answer any questions you have regarding masonry heaters, wood-fired ovens, and cookstoves. Contact Eric today.
