The Best Way To Make A Dry Space Beneath Your Raised Deck

Homeowners are always trying to maximize their usable space. However, using the space underneath a raised deck can be risky if your deck has subpar drainage. Think about it, you wouldn't want to store your pricey lawn mower under your deck if it means that your precious mower will have to contend with a constant deluge of destructive rainwater. Thankfully, homeowners have options for creating dry space beneath their raised deck, including methods for retrofitting existing decks, and solutions that can be built into newly constructed decks.

According to Fine Homebuilding, there are a number of ways to redirect precipitation in order to keep the space under your raised deck dry. The two main approaches are over-the-joist waterproofing and under-the-deck waterproofing. While under-the-deck waterproofing is somewhat more affordable, not to mention easier to implement, over-the-joist waterproofing wins out as the best method thanks to its ability to prolong your decking's lifespan while keeping the area beneath it dry.

If you're building a new deck for your home and want to ensure the end product offers the best waterproofing possible, opting for above-the-joist waterproofing is practically a no-brainer. Above-the-joist waterproofing is usually in the form of a sloped, non-permeable membrane that covers your deck joists below your decking boards. While this method may cost a little extra in the short term, it effectively protects the most important components of your deck from mold and wood rot by redirecting water away from the deck before it even gets to the deck joists, explains Trex.

According to Fine Homebuilding, above-the-joist systems are somewhat costly since they usually include additional costs on top of the price of the waterproofing system itself. However, some pro deck builders can keep costs down by creating a custom system on-site instead of relying on the proprietary materials (and pricing) of popular over-the-joist waterproofing systems. That being said, implementing an over-the-joist system on an existing deck would require the removal and reattachment of the decking in its previous order, which further adds to labor costs, in addition to complicating the project.

Since retrofitting an above-the-joist waterproofing system for an existing deck is labor-intensive and expensive, many homeowners opt for an under-the-deck drainage system to create dry space. However, it's important for homeowners to do their research and select the best firm for the job. This is because under-the-deck water drainage systems leave crucial elements of their decking exposed to water, which can end up costing homeowners in the long run. Luckily, there are a number of effective ways to waterproof your deck joists, notes Plasticine House, that are compatible with under-the-deck drainage systems.

Most under-the-deck drainage systems offer a two-in-one solution that drains water from your deck while providing the area below a finished appearance complete with a ceiling. Despite the potential for creating an aesthetic upgrade under your deck, these systems tend to be fairly affordable compared to over-the-joist membrane systems, and are also rather simple to remove for maintenance if you opt for a user-friendly system. That being said, it's very difficult to replicate the slope of over-the-joist systems when working with under-the-deck drainage solutions (per Fine Homebuilding), so clogs are much more likely to occur.