Materials for a second-story deck must be weather- and rot-resistant, though the specific choices will largely be determined by your budget and style preference. Pressure-treated wood is on the lower end of the price scale, but it can be customized and stained the way you like it. Composite, on the other hand, is pricier for installation and has fewer options for customization, but you’ll save money and time in the long run because it requires little maintenance.

Staining and sealing the underside of a deck creates a moisture barrier but traps water in the boards, quickly leading to rot. No matter how well you seal the above deck, water still gets through via nails and screw heads on the surface. Allow this water to flow naturally under the deck, where it is routed through the drainage system.

Yes, it is possible to add an under-deck drainage system to an existing deck by retrofitting it to the structure. This process may require some prep work. For example, many drainage systems are installed on top of the deck joists, which would require you to remove the decking boards and railings first. To avoid this, you could opt for a below-the-joist drainage system. For best results and to ensure proper installation, it is recommended to consult a professional. A pro can inspect your deck, make any necessary repairs, and then install the drainage system correctly.

Whether composite decking is better than wood depends on your priorities, especially regarding budget and maintenance. Composite decking offers superior longevity (30 to 50 years) and durability, and it is low-maintenance, requiring no sanding, staining, or sealing. In contrast, wood decks typically last 10 to 30 years and need refinishing every few years. While the upfront cost of composite is higher than wood, the reduced maintenance can lead to long-term savings. If a lower initial cost is the primary factor, wood is the more affordable choice.