Molded vs Pultruded FRP Grating: A Project Selection Method
Both products are fiberglass grating, but their internal load paths are different. Molded panels are bidirectional and easy to cut around equipment; pultruded panels concentrate strength along continuous bearing bars for longer spans. The right choice starts with geometry and duty, then moves to resin and surface.
Start with the structural process
Molded FRP grating is produced as a one-piece grid with reinforcement distributed in both directions. This makes it forgiving where panels need field cuts, multiple penetrations or support in two directions. Pultruded FRP grating uses continuous load-bearing profiles tied together by cross rods. Its high strength is directional, so drawings must clearly show the bearing-bar axis.
The practical question is not simply which product is stronger. It is whether the panel geometry, support arrangement and installation method allow that strength to reach the structure.
Match span and load direction
Record the clear distance between support seats—not the overall panel length—and place the bearing direction on the drawing. For molded grating, the two-way grid offers more flexibility, but panel depth and mesh still control deflection. For pultruded grating, orient continuous bearing bars across the clear span and avoid treating the cross-rod direction as equivalent.
State the service load, any concentrated load, the required deflection limit and the support width. If carts or maintenance equipment cross the panel, define wheel or contact loads separately from a uniform pedestrian load.
Select resin for the actual exposure
Resin is the corrosion and fire-performance matrix around the glass reinforcement. A dry indoor area, an outdoor wastewater walkway, a coastal deck and an acid process zone should not automatically receive the same resin. Provide the chemical name and concentration where known, maximum temperature, exposure frequency, UV conditions and any project fire requirement.
General-purpose polyester, isophthalic, vinyl ester and phenolic systems occupy different positions in cost, corrosion resistance, temperature capability and fire behavior. Final selection should follow project-specific compatibility data rather than color alone.
Surface and opening are separate decisions
A concave or meniscus surface may suit dry pedestrian access; embedded grit increases traction in wet or oily zones. Mini-mesh can reduce opening size for heel-safe or small-object-control areas, while covered grating limits splash and debris passage. These choices affect weight, drainage, cleaning and sometimes capacity, so name both the mesh and surface in the schedule.
Detail cutting, supports and clips
Use carbide or diamond tooling, control dust and seal cut edges with compatible resin. Support seats should be level and continuous where required. Clips must match the grating type and environment; stainless hardware is commonly considered for wet or corrosive service. Show panel joints, minimum support bearing, clip family and fixing quantity on approved drawings.
What to send with the RFQ
Send plan dimensions, clear spans, bearing direction, load cases, deflection limit, environment, resin or chemical exposure, mesh, thickness, surface, color, panel sizes, cut-outs, support material and clip preference. Download the 2026 FRP Grating Catalog for the full selection tables and engineering checklist.
Frequently asked questions
Can molded FRP grating be cut in either direction?
Molded grating is bidirectional and is generally more tolerant of cuts in either direction, but cut edges still need sealing and load-carrying cut-outs may need local support.
Is pultruded grating always stronger than molded grating?
Pultruded grating offers high directional strength and can suit longer spans, but capacity depends on series, depth, span, loading and orientation. It is not automatically the better option for every layout.
Which FRP surface is best for wet areas?
A grit surface is a common starting point for wet or oily access, but drainage, cleaning, footwear and the project slip-resistance requirement must also be reviewed.