Honeycomb vents look like a grid of small cells. Each cell is coated with a material that swells when it gets hot, closing the vent before flames and embers get through.
Protection is RF1's read of published tests, not a lab rating. Prices are rough ranges based on a 2024 California study, not RF1 quotes.
How it works
In normal weather, air moves freely through the honeycomb cells and a stainless mesh behind them.
When heat hits the vent, the intumescent coating expands and seals the cells shut.
In NIST's 2025 high-heat tests, honeycomb designs let more flame through than baffle designs once exposure got extreme. No vent design was perfect at that level.
Who makes it
Aluminum honeycomb vents with an intumescent coating and stainless mesh, in eave, soffit, foundation, gable, dormer and roof styles, plus retrofit kits.
They say: Tested to ASTM E2886 and evaluated under ICC-ES ESL-1300, per Vulcan.
Descriptions are each maker's claims, not RF1 test results. Before buying, confirm the exact model on the State Fire Marshal's Building Materials Listing (vents are category 8165).
What it costs
Rough installed costs, based on the 2024 Headwaters Economics study. Vulcan doesn't publish prices; retailers vary.
These are rough ranges, not RF1 quotes. Most RF1 jobs land between $500 and $5,000, and your plan prices every vent before anything is booked.
Wondering whether honeycomb or baffle vents fit your home better?
Compare your mesh to real-size samples, or have Mark check every vent in person, free.
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