Slag is one of the best materials for your driveway. A slag driveway is made of steel byproduct, with similar properties to granite or basalt. It’s compact and capable of withstanding different vehicles’ weights for years. But like other driveway materials, it has its pros and cons.

Slag on your driveway will make it durable. It requires less maintenance, improves the driveway’s aesthetics, and is easier to install. However, if the slag driveway is not stabilized, it can spread under heavy-weight vehicles. Spread slag will erode the soil underneath, resulting in mud holes.

Here is everything you need to know about slag driveway pros and cons before you proceed. 

What Is Slag Gravel?

Slag gravel is one of the driveway materials that’s not as popular as the others. It’s a byproduct of steel produced by smelting ore in the mills. Slag gravel is small glassy chips that can bear vehicles’ weight and is a perfect gravel alternative. Many people opt for it over gravel because it’s cheaper but does wonders on the driveway.

You can also use slag gravel to landscape your backyard, seal roads, or fill potholes in your parking lot. Slag gravel is durable, allowing you to use it on a busy driveway. You can also crush the slag gravel into different sizes for specific use. It’s a green mineral alternative to quarry rocks, making it a good choice for those who like sustainable living.

How Slag Gravel Is Formed?

Slag, which is a byproduct, is formed during ore smelting. It comprises mixed oxides like aluminum, ash, phosphorus, sulfur, and silicon after reacting with furnace linings. During this process, slag covers the top surface of the molten metal, preventing it from oxidation and dirt. After that, it turns into a coarse aggregate that you can use to make your driveway or roads, while others use it as a phosphate fertilizer.

Is Slag Different from Ash?

Yes. What makes slag different from ash is its texture. Slag retains a rough texture after smelting the iron ore. However, fly ash has a smooth texture after further refining. But the two share similar properties as they are made from the same raw material.

Note that ash is smoother than Portland cement, and it’s also cheaper. Most people use it with Portland cement to improve the working surface’s permeability and increase its resistance. The two combinations also help reduce corrosion on the driveway surface and make it stronger and more durable.   

Advantages of Slag gravel On Driveway

If you use slag gravel on your driveway, you’ll love the results because;

  • Slag is durable
  • It has better resistance to wear
  • It’s easy to install
  • It requires less maintenance
  • It helps reduce greenhouse gas emissions, promoting sustainable living
  • It helps conserve the environment as there’s no need to dig rocks or stones for building the driveway
  • It’s cheaper than some driveway building materials

Disadvantages of Slag on Driveway

Apart from slag having its positive sides on the driveway, it has its disadvantages which include;

  • It has toxic ingredients like nickel and chromium, which are dangerous to the human body and the environment.
  • The harmful chemicals can lead to soil and water pollution.
  • It requires you to stabilize it to prevent shifting due to the vehicle’s weight
  • It’s prone to creating mud holes under frequent use.

Is Slag Good for Driveways?

Yes, You will love having slag on your driveway as it helps make it look well taken care of and beautiful. The slag also enables your driveway to last longer without you having to do regular maintenance. It’s a better choice than natural rock for driveway construction because of its high resistance to wear.

It will, in this case, make your driveway last longer while reducing the negative environmental impact of using dug materials like rocks. Slag also creates a heavy base for your driveway and can be used for top dressing, reducing the costs of alternative materials.

The goodness of slag makes it also be used for other purposes like parking lots, backyards, or landscaping.

Is Steel Slag Toxic?

Steel slag comprises harmful ingredients that it retains from the manufacturing process. The toxic chemicals include chromium, nickel, strontium, and cadmium, which are not environment friendly nor safe for human beings.

For example, nickel can trigger allergic reactions and, in worse cases, result in kidney, lungs, and heart diseases. Cadmium in the soil around your driveway will affect the seed germination rate, photosynthesis, and stomatal conductance, which are crucial for the plant’s growth.

How Much Can a Tone of Slag Cover?

This will depend on many factors. Number one is the thickness of the driveway you intend to build. A thicker driveway will require more slag than a thinner one. Also, the length and height of the driveway will determine the area covered by a tone of slag. You also need to give room for correcting imperfect spots to determine the size of the driveway a tone of slag will cover.

How To Make A Slag Gravel Driveway?

The process of installing a slag driveway doesn’t differ much from constructing a gravel driveway. 

You can do that by;

  • Identify where you want the driveway to be. After that, you need to mark its perimeter using a string and landscape stakes.
  • Then remove grass and topsoil from the area. If you can’t do this, consider hiring someone to save on time.
  • After that, you need to determine the amount of slag which will help you finish the work. When doing this calculation, multiply the driveway’s height, length, and depth in cubic feet. After that, convert the cubic feet into cubic yards to help you know the tone of slag to be bought. Then request for delivery and start working on your driveway.
  • You should ensure the path is equally leveled, and then lay a weed barrier to discourage grass growth on your driveway.
  • Finally, spread the slag on the path. Start with the first or base layer. Ensure its compact by pressing it into the soil for a stable foundation. You can use a bulldozer or heavy track for this. Also, do a second layer to increase the strength of the driveway. Afterward, you should spread the top layer and smoothen it out to your desire.

Bottom Line

A slag driveway will help you improve your home’s overall value by making it look beautiful and cared for. The driveway will also prevent your vehicle from pothole damage and allow it to last longer. Most people love slag for their driveway because it’s cheaper and more durable, just like the other materials. It’s also a good green choice as it helps reduce the digging of rocks, which negatively impacts the environment. 

However, you need to stabilize the slag driveway to prevent it from shifting under the weight of bigger vehicles which can be additional costs. It also contains toxic ingredients which can harm the human body and degrade the soil. 

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