How to Use Rock Salt and Grit Salt for Efficient Site Maintenance

Winter weather can present major challenges for keeping construction sites safe and accessible. Icy walkways and roads put you at risk of slips and falls, while snow buildup hinders site access and productivity. Using the right ice-melting materials is important for efficient site maintenance during cold-weather months. Rock salt and grit salt are the 2 common de-icing salt products used to keep sites clear of snow and ice. 

Below, we review the general considerations when evaluating different de-icing salts for construction sites. We offer tips on assessing your worksite to determine the best de-icing fit. In addition, we look at the specifics and benefits of rock salt and grit salt. You will learn what makes each uniquely suited for different on-site applications. 

How do grit salt and rock salt differ on site?

Each material brings its unique characteristics to various surfaces on a construction site, influencing its effectiveness in specific conditions. When deciding between using rock salt or grit salt, you should consider these key factors.

Temperature

Rock salt begins losing effectiveness around 15°F (-9.4°C), with greatly slowed melting below this point. However, grit salt can facilitate reasonably quick melting down to temperatures as low as 0°F (-17.7°C). This is due to added calcium and magnesium for improved cold weather performance. Choose rock salt when temperatures stay near 20°F (-6.6°C). 

Surface material

The gripping agent in grit salt attaches well to hard, porous materials like poured concrete, tarmac, metal floor walkways, and unfinished stone where traction is vital. Also, the calcium and magnesium in grit support melting on cement-based surfaces. Rock salt adheres readily to softer materials like brick, wood plank and stamped asphalt thanks to speedier infiltrating action. However, it struggles to grip on harder finishes.

Environmental impact

High sodium chloride content in many rock salt blends can raise soil salinity, harming vegetation over time. Runoff also risks polluting groundwater drinking supplies, lakes, ponds and watershed regions. Grit salt has a reduced environmental impact and will not remove vital minerals from the surrounding landscape. With both salt types, be mindful of runoff directions, storage methods and application overuse.

Cost

Generally, rock salt is cheaper to buy in bulk, which allows extensive spreading at lower costs. However, grit salt frequently enables lower practical application rates. This is due to better retention and higher effectiveness per granule in many conditions. Compare entire seasonal material budgets accounting for how much of each product may be reasonably required to inform cost decisions.

Timing

Grit salt features fast-activate compounds allowing quicker initial ice penetration after surface application. However, sustained melt periods are shorter than rock salt. This makes grit a favourable option right before workers arrive or when prompt clearing is essential. The slower steadier melt of rock salt then maintains clearance for extended duration in high-traffic zones.

Foot traffic

Embedded aggregate particles give grit salt better traction, leaving visible grip enhancers atop icy walking surfaces even as base melt progresses. This traction reassurance with clear visual cues is ideal for pedestrian-dense zones around the site. Standard rock salt fully liquefies as it melts. It requires diligent monitoring and reapplication on key foot traffic path areas to prevent refreezing slip hazards. Signage can also help indicate gritted zones.

Brown rock salt vs white rock salt: Which is best?

Brown rock salt (also known as red salt) is typically preferable compared to white salt for deicing around construction sites. Below are the main reasons to explain this.

• Brown salt contains higher contamination levels of clay, silt and iron additives. This makes it more effective at breaking ice bonds and permitting cold-temperature applications.
• The darker colouration also enhances the ability to retain heat from sunlight. Also, it quickly facilitates melting in treated areas compared to white salt varieties.
• Although generally more expensive, brown salt improves melting efficiency and lowers overall application rates and usability in extreme temperatures. 

Where to not use rock salt and gritting salt on site

While rock salt and grit salt provide superior safety in winter on active construction sites, proper cleanup and removal practices are equally vital for efficiency, environmental protection and preventing future issues. Here are 6 key areas to avoid during application.

1. Foundations and frames

Concentrated or prolonged exposure to salts accelerates oxidation and deterioration of concrete foundations and metal frame supports. This compromises overall infrastructure integrity over time. You should minimally use rock or grit salt and redirect runoff near these critical structural components.

2. Utilities and equipment

Salts severely corrode vital equipment like generators, electrical systems, tools, and vehicles stored or operating on site. As a result, this leads to impaired function or asset lifespan reduction. Avoid treating areas right around critical utilities or equipment storage zones.

3. Soil and landscaping

Landscaped areas, unfinished green spaces, tree bases and garden soils are all very sensitive to desiccation or contamination issues from high salt exposure. It is important to be discreet and redirect runoff to protect vegetation around your site.

4. Storm drains

Prevent concentrated salts from entering nearby storm drain access points, as these frequently feed downhill into local watersheds. Site runoff redirection away from drains helps avoid ecological impacts.

5. Presence of people

Using excess salts around active outdoor work zones, busy loading bays or pedestrian footpaths heightens slip safety hazards for workers as products dissolve. Be sure to apply carefully around high-traffic areas.

6. Newly treated areas

Allow 10-15 minutes for melting activation before permitting foot or vehicle traffic in recently salted areas. This grants time for permeability while avoiding buildup contributing to slip risks or pool refreezing overnight.

How to safely use rock salt and grit salt on site

For de-icing, you need to follow important safety considerations. We look at essential guidelines on how to safely handle rock salt and grit salt. From proper application techniques to environmental considerations, discover the key practices that ensure efficient site maintenance without compromising safety. 

1. Personal protective equipment (PPE)

When you handle and spread salt, it is important to wear thick, abrasion-resistant gloves, safety goggles or glasses, protective outerwear and steel-toe boots with slip-resistant soles. 

2. Material safety data sheets (SDS)

SDS documentation provides vital health and safety information for all hazardous materials on site, including de-icing salts. All construction professionals on site should review SDS info for the specific type of salt being used before handling.

3. Proper storage

Small or large bags of salt and piles should be stored properly to avoid spillage, tearing, damage or contamination. A grit bin also keeps a bag of salt fresh in between winter weather events, as the lidded units protect contents from external moisture. Make sure to keep your grit salt bin and other storage areas dry. 

4. Limit exposure

Take regular breaks and rotate tasks to limit exposure times when you work on de-icing salts. Overexposure is dangerous and can lead to skin, eye or respiratory irritation. Be sure to wash your hands straight away after contact.

5. Spill containment

Have spill containment equipment and designated washout areas on site to prevent environmental contamination from excess salts. If the salt does leak, you should sweep up accumulated granules regularly.