Under-deck drainage systems

If your deck is on an upper level, you may want to consider installing a dry under-deck drainage system.under-deck drainage system

This drainage system shields the area below the deck from rain and snow and directs rainwater out to the deck’s perimeter and into gutters or a downspout. Having one of these drainage systems installed allows you to make use of the space under your deck by creating an additional outdoor living space. Even if your deck is raised only a few feet, you may want to install one of these systems, so as to have dry storage space under the deck.

The drainage systems can be divided into three basic categories: waterproof sheets that fit over the joists before the decking goes down, ceiling systems that affix to furring strips below the joists, and between-joist systems.
under-deck drainage system

The waterproof sheets that are used for the under-deck drainage systems are usually around 4 inches or so in depth, therefore, you can run wire and junction boxes underneath the troughs. You can then add a ceiling of your choice, for example wood. Another advantage of this method is that the framing is protected from decay as the drainage system keeps everything below the deck boards dry.

The panels of ceiling systems hang from vinyl rails or 2 x 2 sleepers that are attached to the bottom of the deck. They create a finished ceiling while at the same time waterproofing the space underneath. It’s a one time job so you have to like the look of the ceiling. Unlike sheet systems, ceiling systems do not keep the framing dry. This is something to consider if you want to add overhead electrical devices such as lights or fans.

Between-joist systems use the edges of the deck’s joists themselves as a fastening point for the system’s hardware. The hardware then guides the water into a V-panel (dry space) or into a below-joist gutter (under-deck).  As with ceiling systems, the spaces between the joists are exposed to the elements, which you would also have to keep in mind if you are considering electrical devices.