Direct Installation of Composite Decking: Should You Put It on the Ground?

The question of whether composite decking can be put directly on the ground arises frequently among homeowners and DIY enthusiasts. While composite materials offer many advantages, such as increased durability and resistance to weathering, it is essential to understand the proper installation techniques to ensure long-term performance. This article will explore the considerations and best practices for installing composite decking both on and off the ground.

Why Composite Decking Should Not be Installed Directly on the Ground

Composite materials, though more moisture-resistant than traditional wood, still require specific conditions to function optimally. Installing composite decking directly on the ground can lead to several issues:

Ground Contact

Direct contact with the ground can result in moisture buildup. Over time, this can cause significant damage to the decking. Moisture can compromise the integrity of the composite material, leading to warping, mold, and mildew growth. These fungi and bacteria can not only affect the aesthetic appearance of the deck but also pose health risks to the users.

Ventilation

Proper ventilation is crucial for maintaining the structural integrity of composite decking. Composite materials need airflow to dry out after rain or washing. Placing the decking directly on the ground restricts this critical airflow, leading to water retention and potential rot.

Installation Guidelines and Drainage

Most manufacturers recommend installing composite decking on a raised structure such as a frame made of treated wood or composite material that is typically a few inches above the ground. This design allows for better ventilation and drainage. Additionally, proper drainage is essential to prevent water pooling, which can lead to water damage. Ensure that water can drain away from the decking area to prevent these issues.

Can You Build a Deck Directly on the Ground?

Yes, it is possible to build a deck directly on the ground, but there are several considerations to keep in mind:

Builder Options: Some builders may offer to build a deck directly on the ground, with specific modifications such as:

Using ground-contact wood for the base. This type of wood has been treated to resist moisture and is more suitable for direct ground contact. Laying keels or dimensional lumber for the base to provide a secure foundation. However, even with keels, it is generally not recommended to place the composite decking directly on the ground due to the reasons mentioned above. Using real wood instead of keels, which can provide a more aesthetic and natural look.

Pros and Cons of Direct Ground Contact

Pros: Easy to install. Quick and straightforward construction process.

Cons: Higher maintenance requirements. Potential development of problems over time. Frequent need for replacement due to water damage and rot.

For the best results, it is advisable to follow the manufacturer's installation guidelines for your specific composite decking product. These guidelines will provide the necessary instructions to ensure a long-lasting and visually appealing deck. Additionally, always consider the long-term maintenance and durability of the deck to make an informed decision.

Alternative Solutions

While building a deck directly on the ground may be possible in some cases, there are alternative solutions that can offer better protection and longevity:

Concrete Deck

Building a deck on a concrete surface can be an excellent option. Here's why:

Enhanced stability and support. Better resistance to weathering and moisture. Proper drainage and reduced water accumulation.

However, as with any construction project, it's essential to follow the proper installation procedures to ensure the deck's structural integrity and longevity.

Using Piles and DPC

The traditional method of building a deck often involves using piles and damp-proof course (DPC). This technique provides a solid foundation and better protection against moisture:

Piles: These are structural supports that elevate the deck, allowing it to be installed off the ground. DPC: The damp-proof course acts as a barrier to prevent water from spreading into the deck. Bearers and Joists: These components provide additional support and stability to the deck structure. Top Plates: Keeping the top plates elevated helps reduce the amount of surface area in contact with the ground, minimizing the risk of moisture and rot.

This method ensures better protection and longevity for the deck, making it a more viable option in the long run.

Conclusion

While it is possible to build a composite deck on the ground, it is not the recommended approach. The advantages of composite decking, such as durability and resistance to moisture, can be negated if the deck is not installed properly. Instead, consider a raised or elevated structure for the deck. This will provide the necessary airflow and drainage to protect the deck from moisture and ensure it remains in excellent condition for years to come.