Top Questions Answered About Preventing Ground Level Deck Rot

Ground level decks have been gaining popularity in recent years. This type of deck doesn’t need railing or stairs and can easily accommodate the added weight of a hot tub. It also can be located anywhere in a backyard. Despite these advantages, ground level decks have one major drawback: increased likelihood of rot.

Being close to the ground decreases the amount of sunlight and ventilation a deck’s understructure receives, which can quicken mold growth, rot and decay. Accelerated rot can lead to a shorter lifespan, but it doesn’t have to. Below are four common questions to consider before building to ensure a ground level deck can last as long as or longer than its elevated counterparts.

Why do ground level decks rot?

Being close to the ground not only decreases the amount of ventilation and light a deck receives but also increases a deck’s exposure to moisture. Moisture evaporating from the soil on hot, humid days or trapped rainwater can quicken rot and decay. Further, since little light reaches the underside of the deck, the joists are more susceptible to mold and fungal growth. Because it is difficult to access a ground level deck’s understructure, the decay and rot can often go unnoticed until repairs are no longer viable and replacement is necessary.

How can I prevent deck boards from rotting?

The short answer to the above question is nothing will completely prevent traditional hardwood or pressure treated wooden boards from rotting. When using these materials, homeowners can only slow rot by creating enough open space to encourage maximum ventilation and by adhering to routine maintenance that includes environmentally harmful cleaners and fungicide as well as labor-intensive sanding and refinishing.

But there is an easier way. Alternative materials, like composite decking boards, substantially reduce the risk of rot for ground level decks. Decks built with alternative materials will still need some level of preparation, but they will resist rot for longer than traditional materials with virtually no maintenance. The wood-emulating PVC surface layer has anti-microbial properties and is easy to maintain—homeowners merely need to wash it with soap and water when dirty. In addition to resisting rot, these boards will stay truer than traditional wooden boards, which can warp and twist with long-term exposure to moisture.

Ground level deck surrounding a below-ground pool Ground level deck leading to a pool and small yard.

How can I prevent deck joists from rotting?

For ground level decks, joists provide a much-needed separation between the deck boards and the ground. The separation protects deck boards from direct contact with moisture and fungus. But this begs the question, what protects the deck joists?

Homeowners can use small posts to lift the joists off the ground. They can also line the deck’s foundation with garden fabric for additional protection. That said, for traditional materials, like wood, these measures will only slow down the inevitable.

The only way to prevent rot completely is to look beyond wood. Steel deck framing is invulnerable to rot as well as warping and insect damage. There is no need to soak this material in fungicide or refinish it. Finally, select manufacturers of steel deck framing systems offer 25-year warranties, which is longer than the average ground level deck lasts.

How long will a ground level deck last?

When built from traditional wood, ground level decks last, on average, 12 – 20 years. Type of wood, climate and upkeep all influence the lifespan of a deck (no matter its elevation). When homeowners break with tradition and use advanced materials like composite and steel, they can substantially prolong the lifespan of their ground level deck—all without the regular and high-ecological-impact maintenance required by other materials.

Alternative materials keep everything grounded

Ground level decks can add a touch of flair to any outdoor living space and are often easier, quicker and more cost-effective to build when compared to the standard elevated deck. They can also be a source of frustration with their increased likelihood of rot. Even when preventative measures are taken and routine maintenance is meticulously kept, traditional wood frames and decking boards will succumb to rot and decay. Alternative materials from manufacturers like Fortress Building Products not only greatly reduce the risk of rot but also can fit a variety of design aesthetics to ensure a ground level deck remains stylish and rot free.