Thompson’s WaterSeal is a complete line of deck sealers and stains for preserving wood decks from moisture and UV rays. Every one to three years, depending on the type of finish, deck usage, weather conditions, and sun exposure, it is advised to apply a sealer and/or stain to the deck. The majority of Thompson’s WaterSeal products require only a single application on a clean, dry deck and can be applied by the consumer. Some formulations can be applied with a garden sprayer or paint roller, but for a traditional deck stain, a paint pad on an extension pole is the most effective method.
Choosing a Sealer
Selecting a sealer or stain/sealer is the initial step in completing your deck. Generally speaking, a sealer does not color the wood and is designed primarily for protection against moisture, but a stain/sealer contains pigment that helps protect against UV damage in addition to sealing out moisture. There are three fundamental sorts of sealers and stains: transparent sealer, semi-transparent stain, and solid stain. Remember that all deck stains also function as sealants.
The clear sealer provides minimal UV protection but preserves the wood’s natural hue. It is not advised for decks that receive a great deal of sunlight. Additionally, it needs to be treated more frequently than the majority of stains, typically every two to three years, depending on sun exposure.
The semi-transparent stain imparts some color and mild UV protection to the wood. It is the most common deck finish because it provides the optimal blend of UV protection and natural wood appearance. A solid stain is comparable to paint in that it conceals the wood’s grain nearly entirely. Solid stains provide the most UV protection.
When to Seal Your Deck
Consider the following guidelines before applying a deck sealant or stain:
- Deck surface and the air temperature must be above 50 degrees Fahrenheit during the application and drying of a clear sealer.
- The deck surface and air temperature should be between 50 and 95 degrees Fahrenheit for the application and drying of deck stain.
- The prediction should predict no precipitation for at least 24 hours following application.
- Before application, the deck surface must be allowed to dry for at least 48 hours.
- If you intend to use a garden sprayer, you should also wait until a calm day (with little or no wind) to complete your deck.
- The optimum time to apply 1 Stain is when the deck surface is not in direct sunlight.
What You’ll Need
Equipment / Tools
- Broom
- Garden hose with spray nozzle
- Tarp or plastic sheeting
- Garden sprayer
- Synthetic-bristle scrub brush
- Synthetic-bristle deck brush
- Hammer and nail set or drill
- Utility knife
- Sandpaper
- Painting pad or paint roller and tray
- Extension pole
- Paintbrush
- Rags
Materials
- Deck cleaner
- Thompson’s WaterSeal deck sealer or stain
Instructions
- Prepare the Area
Water the grass, plants, and other plants below or near the deck. Cover the plants with a tarp or sheet of plastic to keep the deck cleaner from hurting them. Cover windows, walls, or other surfaces right under the deck to keep sealer or stain from getting on them. - Prepare the Deck for Cleaning
Sweep the deck well to get rid of all the loose dirt and other things. Shake or stir a product like Thompson’s 3-in-1 Wood Cleaner, which is used to clean decks, as directed by the manufacturer. Pour the cleaner into a spray bottle for the garden. - Clean the Deck Railings
Use the garden sprayer to spray some deck cleaner on a small section of the railing and balusters. Plan to clean small areas at a time so you can scrub and rinse all of the wood before the deck cleaner dries. Do not let the wood cleaner dry on it. Let the cleaner sit for 10 to 15 minutes, or however long it says to. Scrub the railing and balusters with a stiff scrub brush with synthetic bristles to get rid of dirt and stains. Use a garden hose and sprayer to spray the area with clean water right away. Clean the rest of the railing in the same way. - Clean the Deck Boards
Use the same methods you used to clean the railings to clean the deck boards, about 10 to 15 square feet at a time. Use a deck brush with a long handle and synthetic bristles to scrub the boards. Work backward from one corner of the deck, ending at a door or set of stairs so you don’t have to walk over the cleaned areas when you leave the deck. Give your wooden deck at least 48 hours to dry. If you put something over grass or other plants, take it off while the deck is drying so the plants don’t die. - Check for Loose or Raised Fasteners
Examine the whole deck for loose or protruding nails or screws, then drive the fasteners below the wood’s surface with a hammer and nail set or a drill. Using a razor-sharp utility knife or sandpaper, remove splinters and other potential risks. Thoroughly wipe away all sanding dust. This step can be performed while the deck is drying after cleaning. - Seal or Stain the Railings
Seal or stain the deck railings according to the product’s application instructions; application methods vary by product. A paint pad is ideal for painting the railing’s large surfaces and balusters, whilst a paintbrush is ideal for corners and narrow spaces. With a garden sprayer, you may also apply a sealant or stain. Apply a uniform coating of sealer or stain to all surfaces, working in tiny areas and keeping the edge wet (do not let the sealer or stain dry before moving to the next area). After finishing each section, inspect the finish for drips or pools, then redistribute or wipe up any excess with your application tool or a clean rag. - Seal or Stain the Deck Boards
Seal or stain the deck boards using the same methods as the railings and your preferred application tool: paint pad, paint roller, paintbrush, or garden sprayer. Apply the finish to 10 to 15 square feet of boards at a time, then remove any excess with a towel or applicator. Work your way from the far corner of the deck to the exit. Generally, it is better to cover a few boards at a time, working down their full length, followed by a few boards in the opposite way. Before utilizing the deck, allow the sealer or stain to dry for 24 to 48 hours (or as suggested) based on the product and the conditions.
Deck Sealing and Staining Tips
Typically, WaterSeal products from Thompson only require one application, however, the second layer of stain can be used to deepen the wood if desired. However, you must wait for the first coat to dry (usually 2 hours) before applying the second coat within 4 hours.
Follow the manufacturer’s recommendations for deck refinishing every one to three years. Deck wood remains in much better condition when it is routinely maintained. Leaving wood untreated for a further year or two typically results in persistent damage that shortens its lifespan.