11-W-4, 15-W-4 and 19-W-4 are all welded bar grating panels with cross bars at 4 in. (100 mm) on centre. The only difference is how far apart the bearing bars sit: 11/16 in. (17.5 mm), 15/16 in. (24 mm) and 1-3/16 in. (30 mm) respectively. That one number decides open area, self-weight, how many bars carry the load, and what can fall through the floor — which is why mesh selection should be made before bar size, not after.
What the Code Tells You
|
Code digit |
Meaning |
11-W-4 |
15-W-4 |
19-W-4 |
|
First number |
Bearing bar spacing in 16ths of an inch |
11/16 in. (17.5 mm) |
15/16 in. (24 mm) |
1-3/16 in. (30 mm) |
|
Letter |
Construction type |
W = welded |
W = welded |
W = welded |
|
Last number |
Cross bar spacing, inches |
4 in. (100 mm) |
4 in. (100 mm) |
4 in. (100 mm) |
W is electro-forge resistance welding with no filler metal, the standard industrial build. S is swage-locked and P is press-locked, both used where an architectural look or a flush top surface matters. R is riveted. All four share the same spacing code, so "11-W-4" and "11-P-4" have the same mesh but different construction, stiffness and price.
Mesh Comparison
|
Designation |
Bearing bar spacing |
Open area (approx.) |
Relative bar count per foot |
Best for |
|
19-W-4 |
1-3/16 in. (30 mm) |
about 80 % |
Baseline |
General industrial platforms, drainage per kg |
|
15-W-4 |
15/16 in. (24 mm) |
about 75 % |
Higher |
Higher point loads, tighter heel safety |
|
11-W-4 |
11/16 in. (17.5 mm) |
about 70 % |
About 70 % more bars than 19-W-4 |
Pedestrian routes, public access, dropped-object control |
|
11-W-2 |
11/16 in. (17.5 mm) |
about 70 % |
Same mesh, cross bars at 2 in. |
Extra lateral rigidity, non-standard lead time |
Prices
A tighter mesh buys safety and costs steel. An 11-W-4 panel carries roughly 70 % more bearing bars per foot than 19-W-4 at the same bar size, so it weighs more per square metre — a 1 in. × 3/16 in. 11-W-4 panel is around 15 lb/ft² (≈ 74 kg/m²) before galvanizing. It also drains slightly less, because open area falls from about 80 % to about 70 %. What you get in return is a floor that a heel, a wheeled bag or a dropped spanner will not vanish through, and more bars sharing every concentrated load.
Span Planning
Bearing bars must run across the span. Indicative clear spans at 5 kPa (100 psf), L/200 deflection:
|
Bearing bar |
Indicative clear span |
|
1 × 3/16 in. (25 × 5 mm) |
≤ 900 mm |
|
1-1/4 × 3/16 in. (32 × 5 mm) |
≤ 1,050 mm |
|
1-1/2 × 3/16 in. (40 × 5 mm) |
≤ 1,200 mm |
|
2 × 3/16 in. (50 × 5 mm) |
≤ 1,500 mm |
These are conservative planning figures, not a substitute for a load table. Ask for the table for your exact span, load case and deflection limit before ordering.
When 11-W-4 Is the Wrong Choice
|
Situation |
Specify instead |
|
Pallet trucks, forklifts or hard wheels |
Heavy-duty welded or press-locked with 1/4 in. bar |
|
Long spans over 1.5 m |
Deeper bearing bar, or 19-W-4 with a larger bar |
|
Maximum drainage per kilogram |
19-W-4 |
|
Budget-driven platform, no public access |
19-W-4 or 15-W-4 |
|
Accessible route needing openings under 13 mm |
Closer mesh or checker-plate panel |
The rule that saves rework: 11-W-4 is a light-duty pedestrian panel. Tightening the mesh makes a floor safer for people; it does not make it a vehicle deck. Traffic, not mesh, sets the bar size.
FAQ
Q: Is 11-W-4 stronger than 19-W-4?
A: At the same bar size, the tighter mesh spreads load over more bars, but the panel is still light duty. For heavy loads, increase bar size and thickness rather than tightening the mesh.
Q: How much heavier is 11-W-4?
A: Roughly 70 % more bearing bars per foot than 19-W-4 at the same bar size; a 1 in. × 3/16 in. panel is around 74 kg/m² ungalvanized.
Q: What does the W mean in 11-W-4?
A: Welded construction, electro-forge resistance welding with no filler metal. S is swage-locked, P is press-locked, R is riveted.
Q: Can I mix mesh types on one platform?
A: Yes. Many projects use 19-W-4 for general areas and 11-W-4 over equipment or public routes, quoted from one drawing.
Send us your span, traffic type and whether the route is public, and we will recommend the mesh with the reasoning rather than just a price.
