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Strongrate Fiberglass Grating · Factory-Direct, home

Guide

How to Install Fiberglass Grating

Updated

To install fiberglass grating, set each panel so its bearing bars span between supports with at least 1-1/2" (38 mm) of bearing on each, then fix it with hold-down clips. US guide specs call for Type 316 stainless steel clips no more than 4 ft (1.22 m) apart, at least four per panel.

What should you check before installing fiberglass grating?

Check the span, the design load and the deflection limit against the fiberglass grating load tables before any panel is set. OSHA 29 CFR 1910.22(b) requires each walking-working surface to support its maximum intended load, and US guide specifications add deflection limits for both the grating and its supports.

Fiberglass grating installation checks: US standards, guide specifications and maker guidance (not Strongrate data)
CheckRequirement or common criterion (in, psf, lb)Basis
Design loadEach walking-working surface must support its maximum intended loadOSHA 29 CFR 1910.22(b)
Walkway design criteria60 psf (2.9 kPa) uniform at 1/4" (6.4 mm) maximum deflection, up to 100 psf (4.8 kPa) uniform or 300 lb (1.3 kN) concentrated at 3/8" (9.5 mm) or L/1201US guide specifications
Typical pedestrian load50–65 psf (2.4–3.1 kPa)2US makers’ pultruded load-table notes
Grating deflection3/8" (9.5 mm) or L/120 for comfort; 1/4" (6.4 mm) or L/200 for a firmer feel3US makers’ load notes; the project engineer sets the limit
Support member deflectionL/180US guide specifications
Impact or dynamic loadsHalve tabulated capacities (or double the design load)US makers’ load tables
Minimum bearing on each support1-1/2" (38 mm)One US maker’s fastener guidance
Openings on an accessible routeNo opening passes a 1/2" (13 mm) sphere; long dimension perpendicular to travel2010 ADA Standards §302.3
Open sides of platformsGuardrail top rail 42" (1067 mm) ± 3" (76 mm), withstanding a 200 lb (0.9 kN) forceOSHA 29 CFR 1910.29
Use the criteria in your project specification and code; these are the common US references.

Notes

  1. 1Use the project’s governing criteria.
  2. 2The governing design load comes from the project specification and code.
  3. 3The project engineer sets the deflection criterion.

How far apart can grating supports be?

Support spacing is the clear span the grating carries at your design load within your deflection limit, so it comes from the load table for the exact product. Do not compare makers’ tables at face value: published safe loads rest on safety factors from 2:1 to 5:1. Strongrate’s 2023 catalog deflection tables are on fiberglass grating load tables; confirm values in your quote and submittal drawings before design use.

Which way should fiberglass grating bars run?

Pultruded grating carries load along its bearing bars, so the bars must span from support to support; the cross rods only tie the bars together. On standard stock pultruded panels the bearing bars run parallel to the panel length, so the panel length runs across the supports. Load tables give capacity by clear span measured along the bars.

Molded grating is one piece with strength in both directions, so it is less sensitive to orientation, but check the maker’s load table for the direction it was tested. On an accessible route, set rectangular or slotted openings with the long dimension perpendicular to the dominant direction of travel, as ADA 302.3 requires.

Pultruded I-bar fiberglass grating, sectionSection through four parallel I-shaped load bars joined by a cross rod, showing bar spacing center to center, the depth and the openings between bars.Section across the load barsBar spacingcenter to centerI-bar (load bar)DepthOpeningCross rodPultruded I-bar fiberglass grating, plan viewPlan strip showing parallel load bars held at a fixed spacing by cross rods that run across them.PlanLoad barsCross rods
Pultruded grating: bearing bars span from support to support; cross rods tie the bars togetherSchematic — not to scale
Molded fiberglass grating, plan viewA square mesh of bars running in both directions, molded as one piece, with square openings between the bars.PlanMesh openingBars run bothways, moldedas one pieceMolded fiberglass grating, sectionSection through three molded bars, showing the top walking surface, the bar depth and the mesh spacing between bar centers.SectionMesh spacingTop surfaceDepth
Molded grating: a one-piece panel with bars in both directionsSchematic — not to scale

How do you install fiberglass grating, step by step?

Tools

  • Tape measure, chalk line and level
  • Saw with a diamond-coated or carbide blade
  • Drill with carbide or diamond bits
  • Wrench or nut driver for clip hardware
  • Safety glasses, gloves, hearing protection and a dust mask or respirator

Supplies

  • Fiberglass grating panels
  • Type 316 stainless steel hold-down clips and hardware (or the clips the grating maker specifies)
  • Edge-sealing resin for cut edges and holes

  1. Step 1: Confirm span, load and deflection

    Check each clear span against the load tables at your design load and deflection limit, and halve tabulated capacities where loads are impact or dynamic.

  2. Step 2: Check the supports

    Make sure supports are level and wide enough to give every panel edge at least 1-1/2" (38 mm) of bearing (one US maker’s rule). US guide specs limit support member deflection to L/180.

  3. Step 3: Lay out the panels

    Run bearing bars from support to support; on stock pultruded panels the bars run along the panel length. On accessible routes, set long openings perpendicular to the direction of travel.

  4. Step 4: Cut, drill and seal

    Cut with carbide or diamond tooling and seal every cut edge and hole with resin; see how to cut fiberglass grating. Keep drilling of pultruded grating to a minimum.

  5. Step 5: Set the panels with the specified gaps

    Set panels on the supports with the gaps at walls, curbs, columns and panel joints that the grating maker’s installation instructions give; ask for the gap figure with your order.

  6. Step 6: Fix the hold-down clips

    Fit clips no more than 4 ft (1.22 m) apart and at least four per panel, or more where your supplier’s rule asks for it, and tighten them to the clip maker’s instructions. Use the clip type made for your grating; see fiberglass grating clips.

  7. Step 7: Guard the open sides

    Install guardrails at open sides and edges as OSHA 29 CFR 1910.29 requires, with the top rail at 42" (1067 mm) ± 3" (76 mm).

  8. Step 8: Inspect and maintain

    Inspect the installed grating regularly and have damage repaired by a qualified person, as OSHA 29 CFR 1910.22(d) requires. Check clip tightness and reseal any new cuts or scrapes.

How do you lay out and fasten clips on each panel?

US guide specifications call for Type 316 stainless steel hold-down clips spaced no more than 4 ft (1.22 m) apart, with at least four clips per piece of grating. Some suppliers ask for more: one specifies at least eight per 4 ft × 12 ft (1220 × 3660 mm) panel, another three per support per panel, or two for panels 2 ft (610 mm) or narrower.

Hold-down clips for one 4 ft × 12 ft (1220 × 3660 mm) panel under published US rules (example layout)
Published ruleSourceClips per 4 ft × 12 ft panel (count)
At least 4 per piece, no more than 4 ft (1.22 m) apart, Type 316 stainless steelUS guide specifications4 or more, within the spacing limit
At least 8 per 4 ft × 12 ft panelOne US distributor8
3 per support per panel (2 for panels 2 ft wide or narrower)One US maker12 (3 clips × 4 supports)
Example layout only: the 12 ft (3660 mm) panel length crosses four supports 4 ft (1.22 m) apart, chosen to show the counting, not as a span recommendation. Check your actual span in the load table and follow your project specification where it differs.

Clip designs and names differ between makers, with molded grating commonly held by Type M, J, F or G clips and pultruded bars by their own hold-downs, so match the clip to the grating type and depth using fiberglass grating clips.

How much bearing does a grating panel need on its supports?

One US maker’s fastener guidance calls for at least 1-1/2" (38 mm) of grating bearing on each support, so a support carrying two panel ends needs room for both. US guide specifications also limit deflection of the supporting members to L/180, so check the steel or FRP framing as well as the grating.

Cut-outs reduce support. One US supplier states that openings up to 10" (254 mm) can be cut in molded grating without added support, depending on depth; check that figure, and any larger opening or any opening in pultruded grating, with the load table and an engineer. Seal cut edges with resin, as guide specifications require.

How are fiberglass stair treads installed?

Stairs follow their own OSHA rule: 29 CFR 1910.25 requires stairs to support at least five times the normal live load and never less than a 1,000 lb (4.4 kN) concentrated load. Guide specifications design fiberglass treads for 100 psf (4.8 kPa) uniform or a 300 lb (1.3 kN) concentrated load. Strongrate’s 2023 catalog lists molded and pultruded stair treads and stair tread covers; see fiberglass stair treads and stair tread covers.

What comes with Strongrate grating?

Strongrate grating is made in Nantong, China, and ships from China. Its DNV type approval requires a manual to be supplied with the product, and its 2023 catalog lists STRONGFIX hold-down clips. Clip types, clip count and gaps for your layout are stated in your quote; until then, follow your project specification and the guide-spec rules above.

Frequently asked questions

Can a 4 ft × 12 ft fiberglass grating panel be set by hand?

Weight decides. One US supplier lists a typical 4 ft × 12 ft (1220 × 3660 mm) molded panel at about 120 lb (54.4 kg) at 1" (25 mm) depth and 180 lb (81.6 kg) at 1-1/2" (38 mm), so plan the crew size and any lifting aid under your site safety plan. Strongrate catalog weights are on sizes, weight and open area.

Does a factory-direct order include installation?

No installation service is documented. Strongrate grating is made in Nantong, China, and ships from China, so plan on your own crew or a local installer. The DNV type approval requires a manual to be supplied with the product.

How often should installed fiberglass grating be inspected?

OSHA 29 CFR 1910.22(d) requires walking-working surfaces to be inspected regularly and repaired by a qualified person. At each inspection, check clip tightness, damaged bars and unsealed cuts or scrapes.

Request a quote

Request a quote with clips: send panel sizes, support spacing and the clip count your specification calls for. Quotes within 1 business day (US Central time); the reply confirms routing and next steps.

Request a quoteOrder a sample
Sources
  1. Fibergrate molded grating guide specification (clips, design loads, edge sealing) (accessed Oct 15, 2026)
  2. Strongwell Section 06 74 13, FRP molded grating and stair treads specification (support deflection L/180) (accessed Oct 15, 2026)
  3. Strongwell Section 06 74 13, FRP pultruded grating and treads specification, revised Nov 2024 (walkway and tread design loads) (accessed Oct 15, 2026)
  4. Bedford PROGrid and PROGrate Grating Catalog 2025 (bearing and clip rules) (accessed Oct 15, 2026)
  5. Direct Metals, fiberglass attachments and clips (accessed Oct 15, 2026)
  6. Grating Pacific molded fiberglass grating page (clip types) (accessed Oct 15, 2026)
  7. Grating Pacific, Molded Fiberglass Grating Sizes (panel weights) (accessed Oct 15, 2026)
  8. Grating Pacific, Industrial Pultruded FRP Load Tables (impact loads) (accessed Oct 15, 2026)
  9. Fibergrate industrial pultruded load tables (pedestrian loads) (accessed Oct 15, 2026)
  10. Bedford I 15-60 load notes (deflection limits) (accessed Oct 15, 2026)
  11. McNichols MS-I-6010 pultruded grating spec page (bar direction) (accessed Oct 15, 2026)
  12. Fibergrate FAQ (molded vs pultruded construction) (accessed Oct 15, 2026)
  13. American Grating molded FRP grating page (cut-outs) (accessed Oct 15, 2026)
  14. OSHA 29 CFR 1910.22, Walking-working surfaces (accessed Oct 15, 2026)
  15. OSHA 29 CFR 1910.25, Stairways (accessed Oct 15, 2026)
  16. OSHA 29 CFR 1910.29, Fall protection systems (accessed Oct 15, 2026)
  17. U.S. Access Board, Guide to the ADA Standards, Chapter 3: Floor and Ground Surfaces (accessed Oct 15, 2026)
  18. DNV Type Approval Certificate TAF0000191 Rev. 1 (conditions: marking and manual) (accessed Oct 15, 2026)
  19. Strongrate product catalog “Your Best FRP Solution” (Sep 2023) (accessed Oct 17, 2026)