Waterproof Deck Coating: The Smart Way To Protect Your Deck

With the winter rains rapidly approaching, homeowners should be thinking about the best ways to protect their home and property from water and storm damage. Waterproof deck coating is one step you need to take to protect your deck as well as any nearby structures.

What Is The Best Waterproof Coating?

While the actual products depend upon the waterproof decking materials, in general, the best option is a Class A-rated, multi-layer, fully bonded deck system that is designed for exterior decks. A paint, stain or DIY product will not deliver the long-lasting results you need to protect your deck.

These types of deck coatings typically include:

• A reinforced base coat (fiberglass or mesh)
• Multiple waterproof layers (not just a single paint layer)
• A texture coat for slip resistance
• A UV-resistant topcoat to handle sun + rain
• A Class A fire rating (required for many SoCal homes)
• A manufacturer’s warranty when installed by a certified contractor

The Right Materials Matter – But They’re Only Half The Equation

It’s easy to assume that picking the “best” waterproof deck coating is the most important part of protecting a deck. In reality, materials account for only about 50% of a successful waterproofing job. The other 50% comes from proper preparation, installation, and attention to detail.

Even a premium, Class A waterproofing system will fail if it is:

• Applied over damp or damaged plywood
• Installed on a deck without proper slope/drainage
• Poorly bonded because the surface wasn’t primed correctly
• Missing flashing at the exterior wall or door threshold
• Not reinforced around railing posts, seams, or transitions

 A contractor doesn’t just “brush on” waterproofing deck coatings — they build a system, layer by layer. That’s why professional deck waterproofing isn’t just a product — it’s a multi-step process that includes:

• Structural inspection (repairing rot, soft spots, cracks)
• Slope correction to prevent standing water
• Proper flashing and edge metal installation
• Reinforced membrane layers (not one thick coat)
• Sealing every penetration and wall joint
• Texture + topcoat for UV protection and slip resistance

Roof Deck & Balcony Waterproofing

In many Southern California homes, second-story decks, roof decks or balconies are placed above the structure of a home, and without proper professional waterproofing services, even a tiny leak can create huge damage.

We often have seen homes with damage on the first-floor walls and ceilings that was due to an improperly waterproofed deck or balcony. Even a leak from a poorly water-tight light switch or a tiny crack around the edge of the drain can allow a significant amount of water to seep into the deck structure.

Balcony waterproofing is a more complex process than many homeowners realize, and it involves much more than applying a waterproof deck coating. Typically, we remove any existing tile and several inches of stucco from around the perimeter of the deck.

We examine the area under the tile to look for structural water damage and repair it as needed. We also concentrate on slope correction. Often, when homes are built, balcony decks are not sloped properly and are flat. Sloping the deck ensures that water runs away from any structures and toward drainage systems. This part of the process can take some time, but it is an essential step that many waterproofing contractors skip.

From there, we install new metal flashing, including drip edge flashing along the perimeter and vertical wall flashing where the deck meets the walls or fascia. At this point, we are ready to apply deck coating materials, and we begin with a base layer, or primer.

From there, we install a waterproof membrane system, and this can include several layers. These layers will need to dry before applying additional layers, so this is often a multi-day process. We also seal areas where the deck meets stucco walls as well as areas around railing posts, thresholds and drains.

Lastly, we often apply a texture coat, which makes the surface skid-resistant and much safer. Then a topcoat or sealer is applied. After that has cured, we water test to ensure that everything is leak-free and ready to go.

What about tile? Tile can be beautiful, but these days, we just don’t recommend placing tile on a balcony or roof deck. No matter how well the tile is installed, grout eventually cracks, and water can become trapped between the tile and the waterproofing system. This can break down tile adhesives and cause the buildup of mold, as well as cause tiles to crack.

Tile also adds a good amount of weight to your deck, and many deck and balcony structures were truly not designed to handle that weight load. In some cases, adding tile will even void the warranty for your deck coatings and membranes, even if these were installed properly.

Other Winterizing Tips

In addition to deck waterproofing, there are several other steps you can take to ensure that your home is ready for the winter storms, including the following:

• Clear Gutters & Drains – Water needs to be able to flow away from your house as easily as possible, and it is essential to have your gutters and downspouts cleaned before the winter rains. It’s also smart to check your yard grading and drainage paths and look for low spots where water pools. These areas need to be regraded to allow water to flow away from your house.
• Trim Back Trees – While we don’t suffer through blizzards and ice storms, our heavy winds can be brutal. Be sure to trim branches near your roof, power lines and outdoor living areas. Weak or dead limbs and branches also need to be removed.
• Roof Inspections – It can be smart to schedule a roof inspection before the winter rains occur. An inspector can check the entire roof, as well as your attic, to ensure that small amounts of water aren’t penetrating the structure of your home. Inspections and minor repairs are far cheaper than paying for water damage, so staying proactive with roof inspections is crucial.
• Seal Windows & Doors – Be sure to inspect your windows and doors. Replace dried or cracked caulking around window frames, and check weather stripping on all doors, including sliding doors.

Thome – Quality Deck Waterproofing in Los Angeles

Looking for a top-rated waterproofing company in Los Angeles? At Thome Waterproofing, our team of waterproofing contractors offers a wide range of services to customers throughout Los Angeles and Ventura counties.

We provide waterproofing deck coatings for all types of decks, including concrete deck coatings, wood deck coatings and pool deck coatings. We also can provide you with balcony waterproofing, roof deck waterproofing, retaining wall waterproofing, and planter waterproofing, as well as all types of below-grade waterproofing and foundation waterproofing.

Whether you need a waterproof deck coating or another of our many services, our team of waterproofing experts can handle any job, big or small, and we serve both residential and commercial clients. Contact us today to schedule a consultation.