Having a beautiful outdoor space extends living areas beyond the walls of the home. One popular home improvement project to enhance outdoor living spaces is the installation of a deck. However, many homeowners choose to go a step further by installing an under deck drainage system. In this blog post, we will explore what an under deck drainage system is, why it's beneficial, and how it can transform your outdoor experience.
What is an Under Deck Drainage System?
An under deck drainage system is designed to keep the area beneath your deck dry and usable by channeling water away. It involves a waterproofing mechanism that collects and diverts rainwater through a series of gutters and downspouts before it can seep through the decking boards. This clever system converts the often-wasted space under your deck into a functional area.
Benefits of Installing an Under Deck Drainage System
Increased Usability
One of the primary benefits of an under deck drainage system is the ability to utilize the space beneath the deck for storage or as an additional outdoor living area. With the drainage system in place, the area stays dry and suitable for furniture, cooking equipment, or recreational activities.
Deck Longevity
When water seeps into the wooden elements of your deck, it can cause rot and deterioration. An under deck drainage system helps in extending the life of your deck by preventing water damage. By directing moisture away, it maintains the structural integrity and appearance of your deck for many years.
Improved Aesthetic Appeal
A well-installed under deck drainage system can enhance the visual appeal of your deck. Many systems allow for the addition of a finished ceiling, light fixtures, or fans, creating a polished and inviting atmosphere below the deck.
Adds Home Value
Investing in an under deck drainage system adds value to your home. It creates more usable space, which is an attractive feature for potential homebuyers. The extended lifespan of the deck and improved aesthetic are also appealing selling points.
How Does an Under Deck Drainage System Work?
The typical under deck drainage system involves several components that work together to create a dry area under the deck. Here's how it functions:
Deck Boards: The system works with any decking material, but composite deck boards are especially effective due to their durability and low maintenance.
Deck Joists: The drainage system is installed under the deck's joists, which support the deck boards. The trays or panels that make up the drainage system are attached here.
Waterproofing Membrane: A specialized waterproofing membrane or panels are installed to catch water that seeps through the deck boards.
Gutters and Downspouts: The system channels water to gutters and then to downspouts, directing the water away from the deck and house foundations.
Optional Ceiling Finish: Some systems offer options for a ceiling finish which can include light installations and other features.
Types of Under Deck Drainage Systems
Above Joist Systems
Above joist systems are installed over the joists but underneath the deck boards. This type requires a specialized membrane that acts as a water barrier. The advantage of an above joist system is that it protects the joists themselves from moisture, potentially extending the overall life of your deck.
Below Joist Systems
Below joist systems hang beneath the joists and are generally easier and less expensive to install. They often involve standard gutter components and can be retrofitted to existing decks without the need for dismantling the surface.
Hidden Systems
Hidden under deck drainage systems provide a seamless look, often incorporating concealed channels to manage water flow. These systems are particularly attractive because of their neat appearance but may come at a higher cost due to their complex installation process.
Installation Tips for Under Deck Drainage Systems
When planning the installation of an under deck drainage system, keep the following tips in mind:
Choose Quality Materials: Invest in high-quality materials that offer durability and resistance to various environmental factors.
Consider Professional Installation: For a flawless installation, consider hiring a professional. They bring expertise ensuring the drainage system is fitted correctly and efficiently.
Plan for Maintenance: Regularly clean out gutters and downspouts to prevent clogs. This maintenance is essential to keep the system functioning smoothly.
Customize According to Needs: Evaluate the space and consider adding features like ceiling finishes, lighting, or sound systems to enhance usability.
Creating A Multi-Functional Space
An under deck area shouldn't be just an afterthought; with an effective drainage system, it offers endless possibilities for creativity and functionality. Here are some ideas to get you started:
Outdoor Living Room: Outfit your dry deck space with comfortable seating, a coffee table, and weather-resistant cushions to create a cozy retreat.
Al Fresco Dining Area: Add a dining table and chairs, and pair it with ambient lighting for lovely evening meals outdoors.
Children’s Play Area: Keep children entertained and protected from the elements by designating a play area beneath the deck.
Things to Consider Before Installation
Before diving into the installation of an under deck drainage system, evaluate these factors to ensure it meets your unique needs:
Climate: Consider how much rain and snow your area typically receives. High precipitation regions may require more robust systems.
Deck Dimensions: Ensure you take accurate measurements for materials and feasibility before installation.
Budget: Set a budget that includes materials and labor costs. Remember, while DIY can be cost-effective, professional installation might offer a better long-term outcome.

Frequently Asked Questions About Under Deck Drainage Systems
How does an under deck drainage system work?
An under deck drainage system channels water away from the surface of your deck, keeping the area beneath dry and usable. When rainwater hits your deck, it typically drips through the gaps between the boards. An under deck drainage system captures this water through a series of panels and redirects it to a drainage system, either along the sides or toward the corners of your deck. This setup not only protects the structural integrity of the deck but also allows you to utilize the space beneath your deck as a functional area, perfect for storage or as an additional living space.
Why should I consider installing an under deck drainage system?
If you want to protect your deck's structural components and extend its lifespan, an under deck drainage system is a smart investment. It effectively prevents water damage by directing precipitation away from the wood and metal components, reducing the risk of dry rot, mold, and mildew. Additionally, a dry under deck space can be transformed into a valuable area for entertainment, relaxing, or storage. The system enhances the usability of your property and can increase the overall value of your home, offering benefits both immediately and in the long run.
What are the different types of under deck drainage systems?
There are generally two types of under deck drainage systems: over-joist and under-joist systems. Over-joist systems are installed on top of the joists before decking boards are laid, which allows water to be diverted easily to gutters and downspouts. This type typically provides the best waterproofing. Under-joist systems, on the other hand, are installed beneath the deck joists and can be added to existing decks. They usually involve attaching a waterproof membrane under the joists to catch and divert water. Each type has its benefits and considerations, so the choice may depend on whether you're building a new deck or retrofitting an existing one.
Can I install an under deck drainage system on an existing deck?
Yes, you can absolutely install an under deck drainage system on an existing deck. Under-joist drainage systems are particularly popular for retrofit projects, as they don’t require you to remove the deck boards. Installation involves mounting a waterproof membrane beneath the joists to capture water as it drips through, then channeling it to gutters. Although you can do this project yourself if you're handy, consulting a professional can ensure a correct and efficient installation that maximizes the lifespan of your deck and integrity of the drainage system.
What materials are used in an under deck drainage system?
An under deck drainage system typically includes materials like vinyl, aluminum, or a specialized rubber or composite membrane. Vinyl and aluminum systems offer great durability and weather resistance, with aluminum often favored for its robust nature and lightweight characteristics. Membrane systems, made from high-quality rubber or composite materials, provide excellent waterproofing and flexibility. Choosing the right material depends on your specific needs, the climate where you live, and your budget. Each has its advantages, but all provide adequate protection against water infiltration.
How do I maintain an under deck drainage system?
Maintaining an under deck drainage system is usually straightforward. Regularly inspect the drains, gutters, and downspouts to ensure they are clear of leaves, dirt, and debris, as blockage can lead to water pooling and potential damage. Cleaning the visible surfaces with a hose or pressure washer occasionally will also help maintain their effectiveness. Check for any signs of wear or damage, such as cracks or detached components, and repair or replace them promptly to prevent water seeping through. Routine maintenance not only prolongs the system's longevity but also ensures the space beneath your deck remains dry and usable.
What is the average cost of installing an under deck drainage system?
The cost of installing an under deck drainage system varies based on several factors, including the size of your deck, the type of system selected, and your geographical location. On average, you can expect to pay between $6 and $10 per square foot for most systems, though high-end products and professional installations may cost more. It's important to get quotes from several contractors to understand the pricing in your area and ensure you're getting a fair deal. While it might seem like a significant upfront investment, the benefits in terms of extending the life of your deck and enhancing your property's usability make it worthwhile.
Can an under deck drainage system support deck lighting or other utilities?
Absolutely, an under deck drainage system can accommodate deck lighting or other utilities such as ceiling fans or speakers, turning your under deck area into a functional outdoor living space. Since the system keeps the area beneath your deck dry, you can safely install electrical fixtures without worrying about water damage. Plan your wiring route through the drainage system to ensure it remains hidden yet accessible for maintenance. Adding utilities not only makes the area more inviting and practical but also makes better use of your investment in the drainage system.
Does installing an under deck drainage system affect the deck's ventilation?
An under deck drainage system should not significantly affect the deck's ventilation if installed correctly. Proper spacing and strategic placements of ventilation openings allow air circulation to maintain proper ventilation around the structure, minimizing moisture buildup. This helps avoid problems like mold and mildew. However, it's important to ensure that the drainage system does not create airtight seals that could trap moisture. A well-designed system allows for adequate ventilation, protecting both the deck and the space underneath from potential issues related to excess humidity.

Diving into the World of Under Deck Drainage Systems
Pros
Expanding Usable Space
By installing an under deck drainage system, you're essentially creating a whole new area under your deck. This can be a game-changer, especially if you're short on space. Imagine sipping your morning coffee in a dry, cozy outdoor nook or setting up a whole new patio area without worry about the weather.
Protection Against Water Damage
One of the standout features of these systems is their ability to protect the area beneath your deck from water damage. By diverting rainwater away, you minimize the risk of mold, mildew, or structural issues. It's like giving your deck a shield against the elements, making it last longer and look better.
Increased Home Value
Believe it or not, enhancing your home with an under deck drainage system can actually bump up your property's value. Potential buyers will love the additional usable space and the longevity this system offers. It's a less obvious but effective way to add some resale value to your home.
Versatility in Design and Use
These systems come with a range of design options. Want to add lighting, fans, or speakers underneath? Go for it! The system supports multiple configurations, so you can create an ambiance that resonates with your personal style. It's like having a customizable outdoor room.
Low Maintenance
Once the system is set up, it requires minimal maintenance. You might need to give it a check-up occasionally, ensuring there are no blockages, but overall, it's designed to be a "set it and forget it" type of installation. Who doesn't love that kind of convenience?
Cons
Initial Cost
One of the most significant drawbacks for many homeowners is the upfront cost. These systems can be pricey to install, especially if you're going for a high-end finish or hiring professionals to do it for you. It's crucial to weigh this initial expense against the long-term benefits.
Installation Complexity
Speaking of installation, this is not typically a DIY project for the average homeowner. It requires some significant know-how in terms of design, construction, and waterproofing. So, if you're not into tackling big projects yourself, you'll need to find and hire reliable professionals, which could add to the cost.
Potential for Leakage
As with any system that deals with water, there’s always a chance of leaks if not installed correctly. Poor workmanship or material defects could lead to water seeping through, which kind of defeats the purpose. Regular checks here and there could mitigate this, but it's worth mentioning.
Limited Retrofit Potential
If you have an existing deck and are thinking about adding an under deck drainage system, you might run into some challenges. Not all systems are suited for retrofit installations, so you could be limited by what you can actually do, often necessitating custom solutions that can increase both complexity and cost.
Aesthetic Constraints
While under deck drainage systems expand space and offer protection, they could also impact the aesthetic of your deck. Depending on the design and materials used, some homeowners find the visible components less appealing. It’s a subjective con, but if aesthetics are a big factor for you, it's something to consider.
Maintenance of Free-Flow
Though marketing often claims low-maintenance, ensuring the system remains clear of debris is essential. Gutters, troughs, or other components can get clogged over time, especially in autumn or if your deck area is surrounded by trees. Regular cleaning might be another task to add to your list.

Final Thoughts
An under deck drainage system is essential for maximizing the usability and longevity of your outdoor space, especially when dealing with unpredictable weather. By efficiently redirecting water away from your deck, you can create a comfortable, dry area below that enhances your home’s aesthetic and functionality.
If you’re considering upgrading your outdoor area with an under deck drainage system, we’d love to help. At US Quality Construction of Columbus, we’re dedicated to providing expert solutions tailored to the needs of homeowners in Columbus, OH. Contact us today to schedule a consultation and discover how we can transform your deck into an inviting retreat.
Tags: rainwater management, waterproof deck, deck drainage,







