De-Icing FAQs: Everything You Wanted to Know About Rock Salt

Posted on 15th December 2025

Whether you're buying rock salt for the first time or just want to brush up on best practices, this guide covers the most common questions customers ask us every winter. From how to use rock salt effectively to how to store it properly and when to apply it, here’s everything you need to know in one place.

If you're planning to buy rock salt online, this is your go-to resource.

1. What is rock salt and how does it work?

Rock salt, or de-icing salt, is made primarily from sodium chloride. When spread on icy surfaces, it lowers the freezing point of water. This helps to melt existing ice and prevent new ice from forming.

It works best when applied before or during freezing conditions and is most effective on hard, flat surfaces like tarmac, concrete or stone.

2. How do I use rock salt on my property?

You can use rock salt on any exterior surface that becomes slippery in winter, including:

• Driveways
• Paths and pavements
• Car parks and access roads
• Entrances and doorsteps
• Outdoor stairs or ramps

Spread a thin, even layer across the surface using a scoop, shovel, or salt spreader. For best results, apply before frost or snow is expected - this is known as pre-salting.

3. How much rock salt should I use?

Here’s a simple guideline:

Light frost: 20g per square metre

Moderate ice: 40g per square metre

Heavy snow or thick ice: Up to 70g per square metre

To work out how much you need, multiply the square metre coverage of your surface by the application rate. See our dedicated guide on how much rock salt to use for a deeper breakdown.

4. What's the difference between white and brown rock salt?

White rock salt

• Cleaner, purer, and less likely to leave residue
• Ideal for homes, schools, shops and high-footfall areas
• Sourced from marine salt deposits

Brown rock salt

• Contains more natural grit, offering added traction
• Better for large-scale or industrial use such as roads and car parks
• Often sourced from UK mines

Both types melt ice effectively, but your choice depends on the setting and desired finish.

5. How should I store rock salt?

To keep rock salt in good condition:

• Store it in a dry, well-ventilated area
• Keep it sealed in its original packaging or in a grit bin
• Avoid leaving bags directly on damp ground
• Protect from rain, snow or high humidity

Proper storage will prevent clumping and preserve the salt’s effectiveness season to season.

6. How long does rock salt last?

If kept dry and sealed, rock salt can last indefinitely. It doesn’t expire, but exposure to moisture can reduce its performance over time. For long-term use, bulk bags should be stored under cover or in a weatherproof container.

7. Can I apply rock salt after it’s already snowed or iced over?

Yes, rock salt still works after snow or ice has formed, although it may take longer to break the bond between the ice and the surface. It’s most effective when used proactively, before freezing conditions develop.

For heavier snow, it's a good idea to clear the surface first and then apply salt to prevent refreezing.

8. Is rock salt safe for pets and plants?

In general, excessive use of rock salt can irritate pets' paws and affect plant health due to salt runoff. If you’re salting around pets or gardens:

• Use white rock salt, which is cleaner and purer
• Apply sparingly and sweep up excess once surfaces are clear
• Rinse paws after walks if pets have walked through salted areas

9. Where can I buy rock salt online?

At Stone & Surfaces Direct, we supply high-quality white and brown rock salt in a variety of sizes:

• 20kg bags - ideal for occasional use or topping up
• Mini, Midi, Urban and Bulk Bags - for full-season protection
• All delivered direct from source to your site, with kerbside drop-off

Browse our full range of de-icing salt online and get your property ready before winter sets in.

10. When should I order rock salt?

Early preparation is key. Rock salt is in highest demand during cold snaps, so it's best to buy ahead of the season. Ordering early ensures you:

• Avoid supply delays during cold weather
• Get the bag size you need
• Are ready to act as soon as frost hits

We recommend stocking up in autumn or early winter to stay ahead of the weather.

11. Do you deliver rock salt across the UK?

Yes. We deliver winter de-icing salt across most of the UK. Delivery is kerbside via pallet, and we offer fast, reliable service on all order sizes.

View delivery info on each product page or get in touch if you have access concerns or need help choosing the right option.

Still Have Questions About Rock Salt?

We’re here to help. Whether you're preparing your home, business or public site, Stone & Surfaces Direct offers expert advice, premium-grade products and a seamless delivery experience.

Browse our full range of de-icing salt today, or contact our team for tailored advice on how to use and store rock salt this winter.