Deck & Patio Drains

Deck and patio drains keep water moving off waterproof membrane systems instead of letting it pond and work its way through seams. Whether you're draining a coated plywood deck, a tiled balcony, or a concrete patio with a sheet membrane underneath, the right drain ties into the waterproofing layer so water exits without compromising the seal.

Common types include scuppers (wall-mounted outlets that let water flow off the edge), channel drains (linear grates set into the surface), and through-deck drains that connect to downspouts below. Choosing the right style depends on the substrate, the deck waterproofing system in place, and how much water volume you need to handle. Most membrane manufacturers specify compatible drain details, so matching the drain to the coating or sheet system is critical for warranty coverage.

Proper drainage is one of the most overlooked parts of a deck coating project. A perfectly applied membrane will still fail if water sits on it long enough, especially at seams and penetrations. If you're evaluating deck coating options, plan the drainage at the same time as the coating, not after.

Related guides

• Deck Waterproofing Guide
• Deck Coating Options
• What Is an Elastomeric Roof Coating?