Herringbone Firebox Restoration — Historic Portland Home
Project Overview
| Field | Value |
|---|---|
| Service Type | Herringbone Firebox Restoration |
| Material | Alumina-silica ASTM C315 firebrick; high-temperature refractory mortar |
| Pattern | 45-degree herringbone, hand-laid |
| Special Features | Period-correct brick sizing; smoke chamber parging |
| License | Oregon CCB #49750 |
Matching 80-Year-Old Brickwork in a
Modern Restoration
The herringbone pattern in a firebox isn’t just decorative. In Portland’s Craftsman bungalows and Arts and Crafts homes, it was used because it’s both structurally sound and visually distinctive. The 45-degree layout distributes thermal stress across mortar joints differently from a running bond, reducing the likelihood of concentrated failure points during rapid temperature swings.
In homes built between 1905 and 1935 across Irvington, Laurelhurst, and Eastmoreland, these original fireboxes are often partially repaired by people who didn’t recognize the pattern. A running-bond patch inside a herringbone firebox isn’t just visually off. It typically introduces different brick thicknesses, mismatched formulations, and incompatible mortar — so it fails faster than the original work.
A proper restoration works with what the original masons built. That means sourcing the right brick, using the correct mortar, and matching the original joint profile.
Portland Chimney & Masonry Inc | 9136 NE Glisan St., Portland, OR 97220 | (503) 256-9140
Hand-Laid Herringbone — What the Work Actually Requires
Pre-1940 firebricks in Portland were often produced at local brick yards and rarely match today’s standard 9″ x 4.5″ x 2.5″ dimensions. In Irvington and Laurelhurst homes, we’ve seen lengths ranging from 8.75 to 9.5 inches, with depth variations of a quarter inch or more. When the original firebox relies on a specific coursing height and exposure, sourcing compatible material becomes critical.
We use alumina-silica firebrick rated to ASTM C315, a high-alumina formulation that handles thermal shock better than standard clay brick. PCMI’s existing herringbone projects specify high-temperature “clippers” (split-cut brick) and alumina-silica material for this reason. Refractory mortar joints run 1/16 to 1/8 inch throughout—standard masonry mortar will crack in a firebox within a single heating season.
We also address what’s happening above the firebox. In Portland’s historic homes, pre-1940 smoke chambers are almost always corbeled (stepped masonry rather than a smooth parged wall). That corbeling creates turbulence just above the firebox throat, which contributes to smoke spillage into the room and faster creosote buildup on cold starts.
We parge the smoke chamber smooth to bring it into compliance with current NFPA 211 and IRC code requirements.
For homes built before 1978, our EPA Lead-Safe Certified team follows federal lead-safe work practices throughout the restoration. In the neighborhoods where this work is most common, that’s not optional but required.
The Firebox Looks Right — and
Works Right
When the firebrick is period-correct and the smoke chamber is properly finished, the firebox performs the way it was designed to. The herringbone pattern reads clean and consistent. The mortar joints match. The draft improves—and the smoke goes where it should.
What Our Customers Say
Portland Chimney rebuilt the top of our chimney… they added liners to each chimney stack and rebuilt our firebox. All went very smoothly and even under budget!
Jen F., Portland
Want to Restore a Herringbone Firebox in Your Portland Home?
Call (503) 256-9140 or request a free estimate. We’ll inspect the existing firebox, identify what’s original and what’s been altered, and define the scope before any work begins.
Portland Chimney & Masonry Inc | 9136 NE Glisan St., Portland, OR 97220 | (503) 256-9140 | portlandchimneyinc@gmail.com | Oregon CCB #49750 | Washington #PORTLCI005PZ