Grip-strut vs bar-grate. Picking the right tread.
The two most common industrial treads in Ontario. They look similar from a distance but they're optimized for different things — and the wrong choice in the wrong environment is a slip-and-fall problem nobody wants.
What each one is
Grip-strut is a perforated, serrated steel sheet — pressed and stretched so each opening has a raised toothy edge. Light, drainable, very high traction in dry conditions, made in single-piece tread units (no field assembly).
Bar-grate is welded steel grating: parallel load-bearing bars (typically 1" × 3/16") with cross-bars (typically 4 in. apart). Heavier than grip-strut for the same span, offered in standard panel widths, treads cut from stock panels.
Grip-strut wins for:
- Lighter applications — low-traffic equipment access, ship's ladders, secondary stair access. The lighter weight makes single-piece treads easier to field-install.
- Dry, oily, or slick environments — the serrated edges bite into rubber soles even when surfaces are oiled or polished. Common on machine shops and process areas.
- Tight clearance applications — thinner tread, lower stack-up.
- Where exact panel sizing isn't critical — grip-strut is fabricated to size; bar-grate cuts from stock panels.
Bar-grate wins for:
- Heavy traffic — bar-grate is stiffer, takes more abuse, lasts longer under high foot traffic.
- Snow and ice — the openings are larger; snow falls through; ice doesn't pond on the surface. Default for outdoor stairs and catwalks in Ontario.
- Sprinkler reach — on multi-tier mezzanines, bar-grate openings allow sprinkler coverage to lower levels. Grip-strut openings are too small for that to be effective.
- Drop-zone tolerance — small parts dropping on grip-strut sometimes catch on the serrations; on bar-grate they fall through to the floor below (which is sometimes a feature, sometimes a hazard depending on what's below).
- Bare-floor feel — flatter, more "concrete-like" foot feel.
Slip resistance — what the data says
Both meet typical industrial slip-resistance requirements when dry. In real-world wet conditions, the rankings shift:
- Dry surface: grip-strut and bar-grate are roughly equal; both are well above the threshold.
- Wet surface: bar-grate edges out grip-strut for water shedding; grip-strut edges out bar-grate for serrated grip on wet surfaces.
- Oily / contaminated: grip-strut wins by a margin — the serrations push through contamination to bare metal.
- Snow / ice: bar-grate wins — the openings are large enough for snow to fall through; grip-strut can hold snow on the surface and refreeze.
Where each one defaults
- Interior egress stairs → bar-grate (with optional checker-plate top-coat in low-traffic landings).
- Outdoor / fire-escape stairs → bar-grate (snow / ice handling).
- Ship's ladders → grip-strut (compact, slip-resistant on the steep pitch).
- Service catwalks → bar-grate (heavy traffic, drainage).
- Equipment access in a machine shop with oil contamination → grip-strut.
Cost note
For typical industrial stair scopes, the cost delta between grip-strut and bar-grate is small — usually within ±5%. The choice is rarely budget-driven; it's environment-driven. Spec the right one for your conditions and move on.