A Comprehensive Comparison:
When planning a landscape or hardscape project, choosing the right material is crucial for achieving both aesthetic appeal and functional performance. Two popular options for ground covering are gravel and decomposed granite (DG). While both materials are often used for similar purposes, they have distinct differences that can influence your choice based on project needs, local climate, budget, and desired look. This article will explore the characteristics, benefits, and drawbacks of gravel and DG to help you make an informed decision for your next project.
What is Gravel?
Gravel is a naturally occurring material composed of small, rounded stones or rocks. These stones can vary in size, ranging from pea-sized particles to larger, more irregular chunks. Gravel is commonly sourced from riverbeds, quarries, and other locations where the natural weathering process has broken down larger rocks into smaller fragments. The most common types of gravel include:
Pea gravel: Small, round stones often used for walkways, patios, and decorative purposes.
Crushed gravel: Angular stones that interlock more tightly, providing a more stable surface.
River rock: Larger, smooth, rounded stones often used for decorative landscaping.
Gravel is popular for driveways, walkways, drainage solutions, and even as a base material for larger landscaping projects.
What is Decomposed Granite (DG)?
Decomposed granite (DG) is a type of gravel made up of small, granular particles that come from the natural weathering and breakdown of granite rocks. Unlike traditional gravel, which often consists of irregular, jagged stones, DG particles are finer and dustier. DG can be found in different colors, including shades of gray, gold, and red, and it has a slightly more compacted, cohesive texture when installed properly.
DG is commonly used in xeriscaping (drought-resistant landscaping), pathways, patios, and even as a base for artificial turf due to its ability to compact tightly and provide a stable surface.
Gravel vs. Decomposed Granite: Key Differences
To better understand which material may suit your project needs, it’s important to examine the key differences between gravel and decomposed granite.
1. Texture and Composition
Gravel: As a more diverse material, gravel comes in a variety of shapes, sizes, and textures. The jagged edges of crushed gravel allow it to lock together better than rounded gravel, but it can still shift and move over time, especially if the underlying surface is not well-prepared.
Decomposed Granite: DG is composed of finer, smaller particles, often with a more uniform texture. When compacted, DG forms a smoother, firmer surface that is less likely to shift. The dust-like consistency of DG helps it bind together tightly, creating a solid, cohesive surface.
2. Appearance
Gravel: The appearance of gravel can range widely depending on the type used. River rocks, for example, have a smooth and polished look, while crushed gravel has a more rugged, angular appearance. Gravel tends to have a more "random" or scattered aesthetic.
Decomposed Granite: DG is typically finer and more uniform in color, with less visual diversity than gravel. Its more consistent appearance can make it look cleaner and more refined, which is often preferred for contemporary or minimalist landscapes.
3. Installation and Maintenance
Gravel: Gravel is relatively easy to install, especially for loose applications like driveways, paths, and drainage areas. However, it often requires a stable base to prevent shifting and rutting. Over time, gravel can scatter, which may require periodic replenishing and re-spreading.
Decomposed Granite: DG also requires a stable base for optimal installation, but it compacts more effectively than gravel, reducing the need for frequent maintenance. DG surfaces can be more prone to erosion, particularly in areas with heavy foot traffic or rainfall, but they can be stabilized with a binder, which prevents shifting.
4. Drainage
Gravel: Gravel provides excellent drainage, as the gaps between stones allow water to flow freely through the surface. This is one of the main reasons gravel is so widely used for driveways and paths in areas with high rainfall or poor drainage.
Decomposed Granite: DG also offers good drainage, although it may not be as effective as gravel in areas with heavy rain. When compacted, DG forms a somewhat impermeable surface, which could potentially slow water movement. However, when applied loosely or mixed with stabilizers, DG can allow water to pass through fairly efficiently.
5. Durability and Longevity
Gravel: Gravel is generally durable and long-lasting, but its appearance can degrade over time as stones shift or are displaced. In areas with high traffic or constant maintenance, gravel may lose its aesthetic appeal faster than DG. It also may require regrading or replenishing after several years, depending on the level of traffic and the amount of rain the area receives.
Decomposed Granite: DG is highly durable once compacted, and it’s less likely to shift or scatter than gravel. However, DG can erode more easily in high-traffic areas, and it may need occasional replenishing or re-compaction. DG tends to be more resistant to fading and wear compared to traditional gravel, but extreme weather conditions can still impact its longevity.
6. Environmental Considerations
Gravel: Gravel can be environmentally friendly, particularly if sourced locally. Its natural composition and the fact that it doesn’t require much energy to process make it a relatively sustainable material. However, gravel mining can cause environmental disruption if not managed responsibly.
Decomposed Granite: DG is often considered more eco-friendly than other materials due to its natural composition and low processing needs. In addition, DG is frequently used in xeriscaping, which helps conserve water in drought-prone regions. However, as with gravel, its extraction can have environmental impacts if not properly regulated.
7. Cost
Gravel: The cost of gravel can vary based on the type of gravel, its source, and the location of your project. Typically, gravel is more affordable upfront, but the need for more frequent maintenance (regrading or replenishing) can add up over time.
Decomposed Granite: DG tends to be slightly more expensive than gravel, especially when stabilizers or binders are added to the material. However, DG often requires less maintenance, so the long-term cost could be comparable or even lower than gravel in some situations.
Pros and Cons: Gravel vs. Decomposed Granite
Gravel
Pros:
Excellent drainage capabilities.
Variety of textures and colors.
Lower upfront cost.
Great for paths, driveways, and areas with heavy traffic.
Cons:
Can shift or scatter over time.
Requires more frequent maintenance, such as replenishing or re-spreading.
May be less stable in areas with heavy foot traffic or rain.
Decomposed Granite
Pros:
Provides a smooth, compacted surface.
Less likely to shift or scatter.
Aesthetically uniform, offering a clean, refined look.
Great for dry, low-maintenance landscapes (xeriscaping).
Excellent for creating stable bases for other structures (e.g., patios, artificial turf).
Cons:
Can erode or wash away in areas with heavy rainfall or traffic.
Slightly more expensive than gravel.
May require stabilization for long-term durability.
Conclusion: Which One Should You Choose?
The choice between gravel and decomposed granite depends on a variety of factors, including the specific needs of your project, the local climate, and your budget. If you are looking for a cost-effective, versatile option that excels at drainage and doesn't mind some upkeep, gravel may be the way to go. On the other hand, if you want a smoother, more compact surface with a refined aesthetic, decomposed granite is a better choice—especially if you’re working in a drought-prone area or prefer low-maintenance landscaping.
Both materials have their strengths and are widely used in landscaping, hardscaping, and drainage solutions. Ultimately, your decision will come down to the specific requirements of your space and the long-term benefits each material offers.