Trex RainEscape Alternative: Dry Deck Options

If you’re building a new deck onto your home, you may wonder what to do with the space below it. Without good planning, you’ll waste an opportunity to create a functional, even beautiful outdoor living space beneath your elevated deck. By creating a waterproof seal for your decking boards, you can install soffit lights, ceiling fans, an outdoor kitchen, a waterproof entertainment system, comfortable seating, and much more.

How can you create something lovely and avoid a murky, muddy pit beneath your deck after rain and snowmelt? There are several dry deck options to consider. Take a look!

One of Deck Membranes and Downspouts

One of your best options for a dry space under your deck is an under-deck drainage system. A quality system of troughs and downspouts will:

• Keep the area below your second-story deck dry and free from the elements
• Protect the substructure of your deck from moisture that can lead to rot and decay
• Help to hold the deck screws in place longer

While you can build your own under-deck drainage apparatus, the easiest — and guaranteed — approach is to choose a complete system. There are two options: above or below the deck joists drainage systems. Making the right choice can mean the difference between having the wood rot on your joists in just a few years or protecting the wooden substructure. Watch how damaging an under-joist system can be in this video.

Here are three reasons to be wary of a below-joist drainage system:

• A below-joist system allows the wood to get wet over and over again as rain drips through the deck boards, over the joists, and into the drainage system below. The water hits the pan and runs out, but not before drenching the joists. 
• Next, this type of system can trap moisture. If installing a ceiling beneath the decking, there’s no air coming in to dry out the wood. The only ventilation is through the quarter-inch or less spaces between the top boards. 
• Finally, in the hot months of summer, high temperatures can cook trapped, wet wood and accelerates the rotting.

On the other hand, an above-the-joist system such as the Trex RainEscape deck drainage system will provide 100% protection of all the joists and beams from moisture penetration. This type of system also helps to hold the screws and fasteners in place longer.

There are other drainage systems on the market. The following chart details your choices:

Be sure to choose a deck drainage system that is simple to install, especially if this a project you are going to DIY. Check out this video on installation from the Home Depot. You’ll see you should need just a few simple tools such as a utility knife and staple gun.

What much will a drainage system cost? Up to $8 retail per square foot. However, you can get a high-quality product on the market for about half that cost. Once you find the product that meets all of your criteria, look at the price per square foot to find one that offers the best quality and value for the dollar without busting your budget. 

Other considerations: check out the materials, which may be HDPE, PVC, vinyl, or EPDM. Trex RainEscape troughs and Trex RainEscape downspouts are made of HDPE (High-Density Polyethylene), which is affordable and high-quality. Additionally, look closely at the warranty.

Under-Deck Ceilings

One alternative to Trex RainEscape is to install an under-deck system or to add guttering beneath the decking boards to draw away the water. Sometimes called deck roofs or roofing, such systems use corrugated plastic or aluminum panels to catch the water that drains through decking material and channel it away from the area below.

Unfortunately, these systems all allow water to drip through the deck boards, over the wooden joists, and into the gutters below. As discussed above, any under-joist system will cause your wood to rot over time.

Waterproofing Decking Flanges

Another dry deck option is to use waterproofing decking flanges in the spacing between your deck boards. These might be installed between the boards during construction — some are made to fit in the grooves of composite decking boards. Other flanges are hammered in between the boards of an existing deck. 

The idea is to seal the spaces and keep rain from dripping through the boards. However, they can be hard to install, difficult to clean and maintain, and potentially leaky. Often homeowners need to caulk or use butyl tape to waterproof seams and other areas that still allow water through. Further, without the right slant, the flanges won’t allow your deck boards to drain.  

Once you’ve considered all of your options for creating a dry space under your second-story deck, go for it. Dream up all of the ways you can use this bonus space, from entertaining to eating to relaxing. You might even create enclosed deck storage space. The choice is yours — make it your own!