The 2 mesh specification of chimney cap & fireplace spark arrester screen is defined by NFPA 211 / IRC R1003.9. The tables below reproduce the standard row — wire diameter, aperture and open area — and convert the count to a micron rating for filtration selection. The technical drawing redraws to the values selected.
2 Mesh Specification Row (NFPA 211 / IRC R1003.9)
| Mesh count | Wire diameter (mm) | Aperture (mm) | Micron rating (u00b5m) | Open area (%) | Material |
|---|---|---|---|---|---|
| 2-Mesh | 1.200 | 11.500 | 11500 | 82.4 | SS304 |
2 Mesh to Micron & Aperture
| Openings per inch | 2 |
|---|---|
| Aperture (opening width) | 11.1 mm |
| Micron rating | 11100 µm |
| Standard wire diameter | 1.6 mm |
| Open area | 76.4 % |
Aperture = (25.4 mm ÷ mesh count) − wire diameter. The micron rating equals the aperture in micrometres; actual retention also depends on particle shape and cake formation.
Wire Diameter Options at 2 Mesh
| Option | Wire dia | Aperture | Micron | Open area | Weight (SS) |
|---|---|---|---|---|---|
| Heavy wire | 2.080 mm | 10.620 mm | 10620 µm | 69.9 % | 4.46 kg/m² |
| Standard wire | 1.600 mm | 11.100 mm | 11100 µm | 76.4 % | 2.64 kg/m² |
| Fine wire | 1.200 mm | 11.500 mm | 11500 µm | 82.0 % | 1.48 kg/m² |
Heavier wire adds strength and abrasion life but closes the aperture; finer wire opens the aperture and raises throughput at the cost of durability. Specify mesh count AND wire diameter to fix the aperture unambiguously.
Open Area & Flow at 2 Mesh
The standard 2 mesh weave presents an open area of about 76.4%. At this count the mesh presents little flow resistance; selection is normally driven by particle retention and mechanical strength rather than pressure drop.
2 Mesh Cloth Weight
Standard 2 mesh stainless cloth weighs approximately 2.64 kg/m² (density 7.93 g/cm³ basis; brass and copper weave roughly 10% heavier, aluminum about one third). Use this figure for roll handling and freight estimation.
Typical Applications for 2 Mesh Chimney Cap & Fireplace Spark Arrester Screen
2 mesh chimney cap & fireplace spark arrester screen is commonly specified for coarse screening and grading, safety guarding, animal enclosures, plaster and render reinforcement, and support layers behind finer filter cloth.
When to Step Up or Down from 2 Mesh
Move to 4 mesh when particles are passing that must be retained. In a multi-layer pack, pair this count with a coarser support mesh downstream to carry the pressure load.
What Chimney Cap & Fireplace Spark Arrester Screen Does
Stopping burning embers from leaving the chimney and keeping birds and animals out, while letting flue gas draw freely.
Fitting & Care
- Inspect the screen at every sweep; creosote glaze can close openings and choke the draft.
- Fit the cap with stainless fasteners so it can be removed for sweeping.
