Chimney Cap & Fireplace Spark Arrester Screen is used for stopping burning embers from leaving the chimney and keeping birds and animals out, while letting flue gas draw freely. NFPA 211 is the reference cited for it on drawings, datasheets and purchase orders.
What NFPA 211 Means for Chimney Cap & Fireplace Spark Arrester Screen
The dimensions in the table below are supplied to suit NFPA 211. Where the standard sets requirements for the finished appliance, device or system, compliance testing of that assembly stays with its manufacturer; we supply the metal mesh part to the drawing and can provide material certificates and dimensional reports with the shipment.
Chimney Cap & Fireplace Spark Arrester Screen Dimensions
| Mesh count | Wire diameter (mm) | Aperture (mm) | Micron rating (u00b5m) | Open area (%) | Material |
|---|---|---|---|---|---|
| 2-Mesh | 1.200 | 11.500 | 11500 | 82.4 | SS304 |
| 3-Mesh | 1.000 | 7.470 | 7470 | 77.8 | SS304 |
| 4-Mesh | 0.800 | 5.550 | 5550 | 76.4 | SS304 / galvanized |
Specifying Chimney Cap & Fireplace Spark Arrester Screen Beyond the Standard
- Opening size: Many codes require openings no larger than 1/2 in (12.7 mm) and no smaller than 3/8 in so the screen does not clog with soot.
- Wire & alloy: SS304 or SS316 heavy wire survives flue heat and creosote; galvanized corrodes quickly.
- Screen area: Free area of the screen should be at least four times the flue area so draft is not restricted.
When Chimney Cap & Fireplace Spark Arrester Screen Is Not the Right Choice
Not a flue liner or rain cap substitute, and not designed for high-temperature industrial stacks.
