FRP Grating Installation Guide: Supports, Clips, Cutting and Sealing

In short: Install FRP grating on level supports with enough bearing on every edge. Published manufacturer guidance for molded grating calls for at least 38 mm (1-1/2 in) of support around all edges and at least four hold-down clips per panel, spaced no more than about 1.2 m (48 in) apart. Cut with a diamond or carbide-grit blade, support the panel while cutting, and seal every cut or drilled edge with a compatible resin so chemicals cannot reach exposed glass fibers. Wear eye protection, gloves and a dust mask. Always follow the installation drawing and the instructions supplied with your grating.

Before you start

Check the delivery

Count panels and clips against the packing list. Check for transport damage, especially at panel edges and corners. Keep panels flat and supported in storage so they do not bend.

Check the support structure

• Level and flat. Supports should be level so panels sit without rocking. Shim where needed.
• Span. Confirm that the actual support spacing matches the span used to select the grating. A longer span than designed increases deflection. See FRP Grating Span and Load Tables.
• Bearing direction. For pultruded grating and rectangular-mesh molded grating, the main bars must span between supports. Check the panel orientation on the drawing.
• Bearing width. Supports must be wide enough to give the required bearing on each edge.

Gather tools and protective equipment

Typical tools listed in manufacturers' fabrication guides:

• Circular saw or angle grinder with a diamond or carbide-grit blade; jigsaw for curved cuts
• Sawhorses or a platform to support panels while cutting
• Tape measure, straight-edge, marker or chalk line
• Sanding wheel or sandpaper
• Edge sealing kit (resin and catalyst compatible with the grating)
• Drill and wrenches for clips
• Safety glasses, gloves, long sleeves and a suitable dust respirator

Installation step by step

1. Lay out the panels

Place panels according to the layout drawing, starting from a reference edge. Align bars between neighboring panels for a neat finish. Leave a small gap where the drawing requires one for thermal movement or tolerance.

2. Mark and cut

Measure twice and mark clearly. Allow for the saw kerf. Support the panel firmly on both sides of the cut so it cannot flex or pinch the blade. On grit-top panels, cut from the smooth underside. Use steady, even pressure; excessive pressure creates heat and ragged edges. Replace worn blades.

3. Sand and seal

Sand cut edges smooth. Then coat every cut, drilled or sanded surface with the sealing resin. Sealing stops corrosive liquids from reaching exposed glass fibers and keeps the edge looking clean. Follow the mix ratio, pot life and cure time on the kit.

4. Place and fix

Set the panel on the supports with the required bearing on every edge. Fix it with hold-down clips. Clips stop panels sliding, lifting or rocking. Tighten fasteners to the torque in the instructions. Over-tightening can crush the bars.

5. Inspect

Walk the installed area. Check that no panel rocks, all clips are present and tight, edges are sealed, and there are no trip edges between panels.

Hold-down clips

Published guidance from one manufacturer for molded grating recommends:

• at least four M-style hold-down clips per panel, and six to eight for larger panels;
• abutting panel edges either supported by a beam or joined with F-type clips at no more than about 610 mm (24 in) centers;
• hold-down clips on all covered grating, because covered panels can be slightly warped and may rock.

Clips are usually stainless steel. For aggressive chemical areas, ask for the clip material that suits the environment.

Cut-outs and penetrations

Pipes, columns and equipment often pass through grating. Molded grating has bars in both directions, so modest openings are usually possible without extra support. One manufacturer's rule of thumb is that no additional support is needed if a hole removes no more than one-third of the panel width. For larger openings, add a support frame around the opening or fix a support bar beneath the cut bars. Always seal the cut edges of an opening.

Pultruded grating carries load mainly along its bearing bars. Openings that cut bearing bars usually need additional support. Ask us to check penetrations at the drawing stage.

Cantilevers and edges

Avoid unsupported overhangs unless the drawing allows them. Published guidance for molded grating limits cantilevers to short distances that depend on depth, with extra clips at the supports. Edge banding is not usually needed for strength on molded grating, but it can be used where people pass through the grating edge.

Safety while cutting FRP

Cutting FRP produces fine glass and resin dust. Manufacturers' guides recommend:

• reading the safety data sheet before cutting;
• wearing safety glasses, gloves and clothing that covers the skin;
• using an approved dust respirator and, where possible, dust extraction;
• cutting in a well-ventilated area and cleaning up dust with a vacuum, not compressed air.

Follow your local regulations and site safety rules.

Pre-fabrication by the factory

Site cutting is straightforward, but factory cutting saves time and gives cleaner, sealed edges. If you send a layout drawing, FIBROVX can cut panels to size, form cut-outs and seal the edges before shipping, and label panels to match the drawing. See FRP molded grating and pultruded grating.

Common mistakes

• Unsealed cut edges. Exposed fibers are a weak point in corrosive areas.
• Too few clips. Panels can slide, lift or rock.
• Wrong orientation. Bearing bars must span between supports.
• Insufficient bearing. Panels need full support on every edge.
• Cutting without support. Flexing panels chip and split.
• No dust protection. Use a respirator and eye protection.

Maintenance after installation

Inspect periodically for loose clips, damaged panels and worn grit surfaces. Re-seal edges that have been damaged or cut later. Clean with water and mild detergent, or as the chemical environment requires. See FRP Grating Guide.

Key terms

• Bearing: The width of panel edge resting on a support.
• Kerf: The width of material removed by the saw blade.
• Hold-down clip: A fixing that secures grating to its support.
• Sealing kit: Resin and catalyst used to coat cut edges.

Watch: Installing FRP Grating in 27 Seconds

FAQ

What blade should I use to cut FRP grating?

A diamond or carbide-grit blade. Standard toothed wood blades wear quickly and leave rough edges.

Do I have to seal cut edges?

Yes. Manufacturers recommend sealing all cut, drilled and sanded surfaces so chemicals cannot reach exposed glass fibers.

How many clips does a panel need?

Published guidance for molded grating calls for at least four hold-down clips per panel, and more for larger panels. Follow the instructions for your grating.

How much support does each edge need?

Published manufacturer guidance calls for at least 38 mm (1-1/2 in) of bearing around all edges for molded grating. Follow your drawing.

Can I weld FRP grating?

No. FRP cannot be welded. Use mechanical fixings and clips.

Can you pre-cut panels?

Yes. Send your layout drawing and we can cut, seal and label panels before shipping.

Related guides

• FRP Grating Guide
• FRP Grating Weight Guide
• FRP Grating Span and Load Tables
• FRP Grating Surface Options
• Technical Resources: datasheets and drawings on request
• FRP Grating Clips: M-Clip, C-Clip and Saddle Clips Explained
• Designing an FRP Platform: Grating, Profiles and Handrail

Sources

• A US FRP grating manufacturer, "Guide to Fabrication" (1-1/2 in edge support, M-clips max 48 in, min four per panel, blades, sealing, safety)
• A US FRP grating manufacturer, engineering guide specifications (clips per panel, F-clips at 24 in, covered grating clips, cut-outs up to one-third panel width, cantilevers, edge banding)
• A US FRP grating manufacturer, Fabrication & Installation Manual (tools, kerf, sealing)