Turn Your Dark, Dank Under-Deck Into a Bright, Usable Space

If you have a second-story or elevated deck with enough headroom when you stand directly beneath it, you can maximize the space and turn it into a usable area where you can rest, relax, have fun, or do something productive.

An under-deck living space might seem like a no-brainer, but the truth is that many homeowners skip on the opportunity. Wood decks do not have solid flooring and cannot provide reliable cover underneath when it rains, turning the ground beneath it muddy during the rainy season. Installing outdoor concrete flooring helps, but the area will remain unusable as long as the ceiling continues to leak with runoffs from the deck above.

The solution? An under-deck ceiling and drainage system.

Ceiling and Gutter System in One

An under-deck drainage system is a straightforward construction. Its purpose is to collect runoffs from the above-deck and lead the water into a gutter system. This could be the home improvement project that will transform your backyard from being an underutilized space to your new favorite hangout.

Here are some pointers on how to install under-deck roofing in your home.


Corrugated aluminum, PVC, fiberglass panels, and plastic sheets that can be draped over slats to form troughs are some of the most commonly used materials for under-deck roofing.


The entire length of the ceiling must be seamless to avoid leaks, so material- and design-compatible fasteners are absolutely necessary. Ideally, under-deck ceilings formed with multiple panels must have an interlocking system that ensures water doesn’t leak between the panels. In cases where the panels must be nailed to the structural beams, the nails must be coated completely with epoxy polyurethane to ensure that the ceiling is entirely waterproof.

The basic method of installing under-deck roofs is to attach structural beams (also called purlins) a little lower beneath the deck joists. The ceiling panels are then nailed or fastened perpendicularly to the beams, the latter holding the former in place.

On one end of the panels are downspouts that open directly into a gutter system. It crucial, therefore, that the panels are pitched a couple of inches lower towards the gutters so that rainwater will flow naturally towards the gutter. The structural beams must be positioned with this in mind, too.

Gutter System

Under-deck roofs are ideally pitched away from the house. This is to keep the water away from the foundation. Pitching the roofing away from the house is especially a must if the exterior walls are made of wood. The exception is if your house is made of brick and you have high-quality gutters attached to catch the runoff from the under-deck ceiling.


To round off the project, coat the ceiling with a fresh coat of paint. Choose a color that matches the exteriors of your home, otherwise the new addition will look out of place.

White is a popular choice because it can help brighten up the deeply-shadowed area beneath the deck. The white paint on the aluminum or PVC membrane also creates a refractive surface for both artificial and natural light, illuminating the space at daytime and nighttime.

Maximize Your Outdoor Space

No matter how tiny the area is below your deck, you can turn it into a comfortable lounging area where you can sit with a cup of coffee in the mornings or evenings, or a workshop space where you can do hobbies like woodworking, painting, drawing, gardening, or playing a musical instrument. It’s just a matter of preparing the space for your use. Since an under-deck roof is affordable and doesn’t take long to install, it’s a good project to start with.