Fiberglass Grating

FRP Grating comes in two categories/varieties - Molded FRP Grating and Pultruded FRP Grating. They both have advantages over the other, depending on the application.

Molded Fiberglass Grating is generally cheaper than Pultruded FRP Grate, and consists of glass set in a big mold, kind of like a giant waffle iron. Because the molded grating iscreated in one big mold, it has uniform load bearing capabilities, even if holes are cut in it, which is an advantage over pultruded grating, which must be supported in situations where it has been cut around objects.

Molded FRP Grate has a much higher resin percentage than pultruded grating, at 65%. What this means is that the corrosion capacities will be higher, depending on the type of resin chosen. At National Grating, all our in-stock grate panels are Vinyl Ester, giving the top quality in corrosion resistance.

The absense of bearing bars in Molded FRP Grates means that there are no mechanical joints that can give way, which does happen with pultruded FRP grate.

Pultruded Fiberglass Grating is a little more costly than molded FRP grate, but has much higher load capacity, and many more options available for a wide variety of applications. The bearing bars are creating by pulling glass strands through a machine, wrapping it in glass fabric, and sealing it with resin. These bars are then assembled with cross bars at every 6".

Pultruded FRP Grate has a wide variety of options, including bar shape, spacing, and resin. I-Bar has higher load capacity than T-Bar, but less than Heavy-Load-Bar. The model number of the grating describes its characteristics: e.g. I-6015 is I-Bar Pultruded Grating with 60% open area and 1.5" thickness.

The process of creating the components of Pultruded FRP Grates uses less resin and more glass than molded grating, 65% glass and 35% resin. This creates a grate panel with a higher load capacity and slightly lower corrosion resistance.