Quick Answer: Building a wood-fired pizza oven from scratch means following the classic “Pompeii” dome design: a firebrick dome over an insulated hearth, sized to a 36-inch or 42-inch interior floor diameter per Forno Bravo’s widely-used plans, with the door opening set to 63% of the dome’s interior height for correct draft. Material costs run $150-$500 for a simple cob oven up to $600-$1,200 for a full 36-inch firebrick dome. The build itself is usually a weekend project, but skipping refractory mortar in favor of regular Portland cement, or skipping the 5-day post-build curing schedule, are the two mistakes that crack an oven within its first season.
If you searched “how to build a pizza oven,” you likely want to build one yourself from raw materials — not buy a pre-cut assembly kit (see our outdoor pizza oven kit roundup for that) or a finished, factory-cured oven you just place and fire up (see best brick pizza oven). This guide covers the from-scratch build: design, materials, the dome, and the curing schedule that determines whether it survives its first year.
Pizza oven build, by the numbers
- 36” or 42”: the two standard interior floor diameters in Forno Bravo’s Pompeii oven plans — 36 inches fits one large pizza with room to rotate it, 42 inches fits two.
- 63%: the door-opening height as a percentage of the dome’s interior ceiling height — get this ratio wrong and the oven drafts poorly, smoking out the front instead of drawing air up through the chimney.
- $600-$1,200: typical material cost for a 36-inch firebrick dome, including $400-$650 in firebrick alone at $3-5 per brick.
- 5 days: Forno Bravo’s recommended curing schedule after the build — small fires on days 1-2, then roughly +50°F per day to the interior dome temperature until it reaches about 500°F by day 5.
- 170°F: the equilibrium hearth-floor temperature under a properly insulated 800°F cooking surface with a 2-inch FB Board insulation layer — Forno Bravo measures this as roughly twice as efficient at holding heat in (not leaking it into the ground) as an equivalent layer of loose vermiculite board.
Step 1: Pick your design and size
Two DIY paths cover almost every backyard build. A cob (earthen) oven — sand, clay, and straw formed by hand over a temporary sand mold — is the cheapest and most forgiving for a first build, at roughly $150-$500 in materials, but it’s less durable and holds heat for a shorter window than masonry. A firebrick “Pompeii” dome — the design most published plans (including Forno Bravo’s free downloadable set) are built around — costs more but lasts decades and retains heat far longer.
For the firebrick route, Forno Bravo’s plans specify 36-inch or 42-inch interior floor diameters as the two standard sizes. Thirty-six inches is what most home builders land on: enough room to comfortably turn one large pizza with a peel, without the extra brick count and longer heat-up time a 42-inch dome needs. Go smaller only if patio space is genuinely tight — undersized domes make it harder to keep a pizza clear of the flame while it turns.
Step 2: Budget the materials
| Build type | Typical cost | Key materials | Skill level |
|---|---|---|---|
| Cob / earthen oven | $150-$500 | Sand, clay, straw, temporary sand mold | Beginner-friendly |
| 36" firebrick dome | $600-$1,200 | Firebrick, refractory mortar, insulation, hearth slab | Intermediate masonry |
| Firebrick alone (36") | $400-$650 | ~9"x4.5"x2.5" medium-duty firebrick, $3-5 each | — |
| Refractory mortar | ~$75-100 | 3-4 bags at ~$25/bag | — |
| Insulation | ~$90-135 | 2-3 bags at ~$45/bag (ceramic fiber or vermiculite-cement) | — |
Costs are typical 2026 material prices for a 36-inch dome and move with regional supplier pricing; get local quotes before budgeting a firm number.
The mistake that costs builders the most in do-overs: substituting regular Portland cement mortar for refractory mortar to save money. Portland cement cracks under the repeated heating and cooling cycles a wood-fired oven goes through — it’s simply not rated for the temperature swings, and a cracked dome mortar joint is a much bigger repair than the money saved buying the wrong bag up front.
Refractory Mortar & Firebrick Set
- Refractory mortar is non-negotiable for the dome and cooking floor — regular cement mortar cracks under oven heat.
- Standard medium-duty firebrick runs about 9" x 4.5" x 2.5"; a 36-inch dome uses roughly 100-150 bricks depending on design.
- Buy 10-15% extra brick for cuts and breakage — expect to cut many bricks in half for the dome courses.
Stocking up on build materials for a weekend project? An Amazon Prime free 30-day trial gets refractory mortar, firebrick sets, and insulation blanket to your door in two days, so a missing bag doesn’t stall the build mid-weekend.
Step 3: Build the insulated hearth
The hearth is the foundation the dome sits on, and it needs its own insulation layer — a solid slab of plain concrete under the cooking floor will slowly bleed heat straight into the ground, working against everything the dome is trying to retain. Forno Bravo’s own hearth design uses a 3½-inch structural concrete slab topped with either 4 inches of vermiculite concrete or a high-efficiency insulating board layer before the firebrick cooking floor goes down.
The insulation choice matters more than it looks: Forno Bravo measures a 2-inch insulating board layer as reducing an 800°F cooking-floor temperature to roughly 170°F at the layer’s underside at equilibrium — about twice as efficient at holding heat in as the same thickness of loose vermiculite board. That difference shows up directly in how long the oven holds cooking temperature after the fire dies down.
Step 4: Build the firebrick dome
The dome itself is built up in courses of firebrick, most of them cut in half to form the curve — a standard medium-duty firebrick (about 9” x 4.5” x 2.5”) is the building block most published Pompeii plans, including Forno Bravo’s free downloadable set, are designed around. The detail that determines whether the finished oven actually drafts correctly rather than smoking out the front: the door opening height should measure 63% of the dome’s interior ceiling height. That ratio is what pulls smoke up and out through the flue instead of pooling at the mouth of the oven — get it noticeably wrong in either direction and the oven will smoke on you every time you fire it.
Once the brick dome is complete, it needs its own insulation on the outside — a ceramic fiber blanket or vermiculite-cement layer wrapped over the dome, finished with a weatherproof stucco or render coat. This outer insulation layer is doing a different job than the hearth insulation underneath: keeping heat inside the cooking chamber rather than radiating off the dome’s exterior into the air.
Ceramic Fiber Insulation Blanket
- Sits directly over the completed firebrick dome, under the final stucco/render layer.
- Alternative: a vermiculite-cement mix, cheaper but less efficient per inch of thickness than a dedicated ceramic fiber blanket.
- Don't skip this layer to save money — an uninsulated dome radiates heat away almost as fast as the fire produces it.
Step 5: Cure the oven before the first real bake
A freshly built masonry oven still holds construction moisture deep in the refractory, and firing it straight to full 800°F+ cooking heat is the single biggest cause of serious cracking (not the harmless hairline cracks that show up on any wood-fired oven over time — see our pizza oven repair guide for that distinction). Forno Bravo’s recommended schedule: small fires only on days 1-2, then raising the interior dome temperature by roughly 50°F each day, reaching about 500°F by day 5, with each fire burning 6+ hours. Track the climb with an infrared thermometer rather than guessing by eye — the whole point of the schedule is a slow, measured ramp, not a fast one.
Infrared Thermometer
- Point-and-read dome and floor temperatures without opening the oven and losing heat.
- Essential for following a curing schedule accurately instead of guessing by how the fire looks.
- Keeps earning its keep after curing — see our best infrared thermometer roundup for picks.
Build it, assemble a kit, or just buy one finished?
- Build fully from scratch (this guide) if masonry work is part of the appeal, you want the lowest raw-material cost, and you have a free weekend plus the patience for a 5-day cure.
- Buy a kit instead if you want to build it yourself without sourcing and cutting every brick — see our outdoor pizza oven kit roundup for pre-cut foam-form and pre-measured material options.
- Buy a finished oven instead if you’d rather skip building entirely — see best brick pizza oven for factory-built masonry ovens that arrive cured and ready to fire.
- Buy a portable metal oven instead if speed matters more than a permanent masonry build — a Gozney or Ooni heats in 15-20 minutes; see our best outdoor pizza oven roundup.
FAQ
See the frequently asked questions below for build cost, sizing, mortar type, curing, and how a full build compares to a kit.
Bottom line: a DIY wood-fired pizza oven comes down to two decisions that determine whether it lasts — use refractory mortar, never regular Portland cement, and follow the 5-day curing schedule before the first full-heat bake. Size it to the standard 36-inch interior diameter unless patio space or pizza volume pushes you to 42 inches, get the door-to-dome-height ratio to 63%, and budget $600-$1,200 for a proper firebrick build. If that’s more build than you want to take on, our outdoor pizza oven kit and best brick pizza oven guides cover the assemble-it and buy-it-finished alternatives.
Build specs and pricing sourced from Forno Bravo’s published Pompeii oven plans and insulation guidance, current as of August 2026.