Minus Gravel vs. Screened Gravel: Understanding the Difference
When it comes to construction and landscaping projects, the type of aggregate material used can make a significant difference in the outcome. Gravel is one of the most commonly used aggregates, and it’s essential to choose the right kind for a specific project. Two popular choices are minus gravel and screened gravel. While they might seem similar, they have distinct characteristics that suit different applications. This article will explore the differences between these two types of gravel.
1. Composition & Texture:
Minus Gravel:
– Minus gravel, often referred to simply as “minus,” contains fines. Fines are the tiny particles or dust that are mixed in with the larger gravel particles.
– The name ‘minus’ comes from the fact that the gravel is a mix of sizes “minus” the specified sieve size. For instance, 3/4-inch minus gravel would contain particles of varying sizes from 3/4-inch down to fine dust.
Screened Gravel:
– Screened gravel has been sifted or “screened” to remove the fines. As a result, it consists mostly of uniform-sized particles without the inclusion of smaller dust or fine particles.
– The particle sizes are more consistent, which gives it a cleaner appearance.
2. Compaction & Stability:
Minus Gravel:
– The presence of fines in minus gravel allows it to compact well. When watered and compacted, the fines fill in the gaps between the larger particles, creating a more stable surface.
– It’s ideal for pathways, driveways, or as a base layer beneath pavers because of this compaction ability.
Screened Gravel:
– Without fines, screened gravel doesn’t compact in the same way as minus gravel. It remains relatively loose.
– This type of gravel is ideal for drainage projects or decorative purposes where compaction isn’t desired.
3. Drainage & Permeability:
Minus Gravel:
– The fines present can reduce the rate of drainage. Over time, especially if compacted, it can become nearly impermeable.
– This can be advantageous in pathways or driveways where water runoff is not wanted but can be a disadvantage in areas where good drainage is needed.
Screened Gravel:
– Given its uniform particle size and lack of fines, screened gravel has excellent drainage properties.
– It’s often used in French drains, septic drain fields, or other applications where water permeability is a primary concern.
4. Appearance:
Minus Gravel:
– Has a more mixed appearance due to the presence of both large gravel pieces and fine particles.
– Might appear denser and can become quite smooth when compacted.
Screened Gravel:
– Offers a cleaner, more uniform look without the fine particles.
– Maintains its textured, rough appearance even when used over large areas.
Conclusion:
When deciding between minus gravel and screened gravel, it’s essential to consider the project’s needs. If compaction and stability are priorities, minus gravel might be the way to go. However, for projects requiring good drainage and a uniform appearance, screened gravel could be the better choice. By understanding the characteristics and benefits of each, one can make an informed decision and ensure the success of their project.
