Expanding your outdoor living area is a common goal for homeowners, especially those with elevated or second-story decks. Typically, the space beneath a deck is wasted because it becomes wet and muddy whenever it rains. Trex RainEscape is a specialized under-deck drainage system designed to solve this problem by diverting water away from the area below. By installing this system, you can create a dry, usable space for a patio, storage, or even an outdoor kitchen.
Understanding the Trex RainEscape System
Trex RainEscape is a unique drainage system that uses a series of troughs and downspouts to catch water that falls between deck boards. Unlike systems that attach to the bottom of the deck joists, this system is installed above the joists before the decking boards are laid down. This design ensures that the wooden substructure remains dry, which significantly extends the life of your deck frame.
The system is made from high-quality plastic and specialized butyl tape. It is designed to be durable enough to handle heavy rainfall and temperature fluctuations. Because it sits on top of the joists, it creates a waterproof barrier that protects the wood from rot and decay while allowing you to finish the ceiling below with lighting, fans, and entertainment systems.
The Primary Benefits of Under-Deck Drainage
Investing in a drainage system offers more than just a dry spot to sit during a rainstorm. It fundamentally changes how you can use your property. Here are the most significant advantages of choosing a high-quality drainage solution like Trex RainEscape:
- Expanded Living Space: You effectively double your usable outdoor square footage by creating a dry patio area underneath your existing deck.
- Structural Protection: By keeping the joists dry, you prevent the wood from rotting or developing mold. This can add years to the lifespan of your deck’s foundation.
- Electrical Safety: A dry environment allows you to safely install recessed lighting, ceiling fans, and even outdoor speakers or televisions in the ceiling below the deck.
- Increased Property Value: Finished outdoor spaces are a major selling point for modern homes, providing a high return on investment.
- Debris Management: The system helps channel away small debris and pine needles that might otherwise collect on the joists and cause moisture traps.
Essential Components of the System
Before beginning an installation, it is important to understand the different parts that make up the drainage network. Each component plays a specific role in ensuring the area remains completely watertight.
Troughs
The troughs are the long, flexible plastic sheets that run between the joists. They are sloped to ensure that gravity pulls the water toward the edge of the deck. They are typically available in black or brown to blend in with the shadows of the deck structure.
Downspouts
Downspouts are the funnels located at the end of each joist bay. They collect the water from the troughs and direct it into a standard gutter system. These are critical for preventing water from splashing back onto the house or the support beams.
Butyl Tape
Specialized butyl tape is used to seal the edges of the troughs to the joists. This tape is waterproof and creates a permanent bond that prevents leaks. It also acts as a barrier between the deck screws and the joists, sealing the holes as the screws are driven through the decking.
Step-by-Step Installation Guide
Installing a drainage system is most easily done during the construction of a new deck. However, it can also be installed on an existing deck if you are willing to remove the current deck boards. Follow these steps for a successful installation.
1. Planning and Preparation
Measure the distance between your joists. Most decks use 12-inch or 16-inch spacing. Ensure you have purchased the correct width of troughs for your specific joist layout. Clean the tops of the joists to ensure the butyl tape will adhere properly.
2. Installing the Downspouts
Start at the end of the deck where the water will exit. Cut a hole in the rim joist or position the downspout so it can drain into an external gutter. Secure the downspout to the joists using staples or small galvanized nails. Ensure it is centered within the joist bay.
3. Laying the Troughs
Roll out the trough material starting from the house and moving toward the downspout. The trough should have a slight overlap into the downspout funnel. Use staples to temporarily hold the trough in place along the top of the joists. It is important to create a slight “sag” in the middle of the trough to encourage water to flow down the center rather than toward the wood.
4. Securing with Butyl Tape
Once the troughs are positioned, apply the butyl tape along the entire length of every joist. The tape should cover the staples and the edges of the troughs. Press the tape down firmly to create a watertight seal. This is the most important step for preventing leaks.
5. Wall Flashing
At the point where the deck meets the house, use wall flashing to ensure water cannot seep behind the ledger board. This creates a continuous waterproof path from the house siding down into the drainage troughs.
Why Above-the-Joist Systems Are Preferred
There are two main types of deck drainage: above-the-joist and below-the-joist. Professionals often recommend above-the-joist systems like Trex RainEscape for several reasons. First, they protect the wood. Below-the-joist systems allow water to flow over the joists before hitting the drainage pan, which means the wood still gets wet and can eventually rot.
Second, above-the-joist systems are easier to maintain. Because the troughs are protected by the deck boards, they are less likely to be damaged by wind or animals. Furthermore, they allow for a much cleaner look when finishing the ceiling below, as the drainage hardware is completely hidden from view.
Maintenance and Long-Term Care
One of the best features of this drainage system is that it requires very little maintenance once installed. However, a few simple steps can ensure it functions perfectly for decades. Every spring, it is a good idea to spray water between the deck boards with a garden hose to flush out any fine silt or pollen that may have collected in the troughs.
You should also regularly clean the external gutters that the downspouts drain into. If the main house gutters are clogged, water can back up into the drainage system. Aside from keeping the exit paths clear, the system is designed to be “set it and forget it,” providing reliable protection year after year.
Conclusion
Trex RainEscape is a highly effective solution for anyone looking to maximize their outdoor space and protect their home’s structure. By diverting water away from the joists and the area below, you create a versatile environment that can be used regardless of the weather. Whether you want a dry storage area or a fully finished outdoor living room, this system provides the foundation you need for a successful project. To learn more about improving your home’s exterior, explore our other articles on deck maintenance and outdoor renovation tips.