WHAT TEMPERATURE SHOULD YOU GRIT A COMMERCIAL SITE?

Commercial gritting should not be triggered by one air-temperature number alone. The more useful question is whether the site’s surfaces are forecast to become cold enough for hazardous ice to form when moisture is present.

IS 0°C THE GRITTING TEMPERATURE?

Freezing point is an obvious reference, but a professional winter-maintenance decision should not simply wait for an air-temperature reading of 0°C. Roads, car parks and walkways can cool at a different rate from the surrounding air, and the forecast sequence of temperature and moisture matters.

AIR TEMPERATURE VS ROAD-SURFACE TEMPERATURE

Air temperature describes the atmosphere; road-surface temperature describes the surface where vehicles and pedestrians actually travel. Surface temperature can be influenced by cloud cover, wind, shade, exposure, elevation and the material of the surface.

That is why commercial winter planning should consider forecast road-surface conditions alongside air temperature.

WHY MOISTURE MATTERS

A cold dry surface does not present the same conditions as a cold wet surface. Rain, dew, residual water, sleet and melting snow can all influence ice risk. Treatment decisions therefore need to consider both temperature and available moisture.

RAIN BEFORE A FROST

Rain can affect existing treatment and leave surfaces wet as temperatures fall. The timing of precipitation and the expected temperature afterwards can influence whether additional treatment is appropriate under the agreed winter plan.

SHADE, EXPOSURE & LOCAL COLD SPOTS

Different parts of the same commercial site can behave differently. Shaded areas, bridges or exposed sections, gradients and locations with known drainage issues may need particular attention when the treatment plan is prepared.

SNOW & FREEZING CONDITIONS

Where snow is forecast, preventative treatment may form part of the wider response, but snow accumulation can require separate clearance arrangements. Once snow is cleared, underlying surfaces may still need treatment where freezing or refreezing remains a risk.

HOW WEATHER MONITORING SUPPORTS THE DECISION

Weather information can be assessed against the agreed treatment criteria for a commercial site. This helps move winter maintenance away from guesswork and towards a documented, forecast-led process.

Read how weather monitoring can trigger a gritting visit.

WHAT SHOULD FACILITIES MANAGERS DO?

Facilities teams should have a clear winter plan identifying treatment areas, operating priorities and the process used to make treatment decisions. Useful records can include forecast information, treatment decisions and completed service records.

See our facilities managers’ winter checklist.

COMMERCIAL GRITTING TEMPERATURE FAQS

Should we grit whenever the air temperature reaches 0°C?
Not automatically. Surface temperature, moisture, site exposure, residual treatment and the forecast should all be considered.

Can a surface freeze when the general air forecast looks slightly warmer?
Surface and air temperatures can differ, which is why road-surface forecasts and site conditions are important.

Does rain affect the decision?
Yes. Rain and residual moisture can materially affect ice risk and treatment timing.

Should shaded areas be treated differently?
Known cold spots and shaded areas should be identified when the site-specific winter plan is prepared.

When should treatment take place?
Read our guide on when a commercial site should be gritted.

Explore our commercial winter services and Great Britain coverage.