A contractor applies finish to a deck in this example image.

Deck Finishing 101

What every pro needs to know before their next deck job

In many markets, summer is the peak season for deck finishing—and for the many professional painters who offer deck finishing services, that’s a great opportunity to pick up some extra work and improve your business’ bottom line.

Whether this is your first time working on decks or you’ve been doing it for decades, every painter can benefit from brushing up on the fundamentals. That’s because deck projects frequently come with high homeowner standards and several potential pitfalls, according to Dennis Fiorilli, Director of Product Excellence at Sherwin-Williams.

“Customers often have very high expectations for their decks,” Fiorilli says. “So it’s worth doing the research and really understanding best practices in staining, because we want to make sure we do it right.”

Fiorilli shared his top tips for deck finishing success, from start to finish on your next job. 

Start Your Prep Right

Fiorilli recommends starting the prep process by walking the deck to see what condition it is in.

“Decks can take a pretty good beating,” Fiorilli says. “Whether it’s been through rain or snow from changing seasons or just endured the hot sun beating down on it, you need to make sure that this deck is still a sound surface to coat. Walk the deck and see if there’s anything beyond what a coating can protect. Is there damaged wood? Are there screws loose or nails popping? Are parts damaged or in need of repair? Those issues need to be handled—whether by your team or another contractor—before you start the real prep.”

If the deck is in good condition, the next step is getting it prepped to receive the coating.

“For deck finishes—just like we would say for paint—we want the surface to be clean, dull, and dry,” Fiorilli says.

First, thoroughly blow off or sweep away any debris.

Next, if this deck has been stained before, conduct a water test on the deck. Pour a small cup of water onto the deck in a couple of areas and see whether the water beads up. If it does, the deck is still sealed with the previous coating. It will not accept the new stain unless the old stain is removed first. You’ll need to use a stain and sealer remover to get rid of the old deck stain, likely paired with another product to rinse it off when complete. (More details on that in the next section!)

If no stain and sealer remover is necessary, you can clean the deck. Some contractors like to pressure wash decks to get them clean, but Fiorilli recommends lightly rinsing the deck with a deck wash like SuperDeck® Deck Wash (which can be applied using a pump sprayer like the Chapin Clean ‘N Seal Poly Deck Sprayer).

This is because pressure washing, when done poorly, can inject too much water into the wood. You’ll have to wait longer for it to dry before the stain can be used, which is lost time you could be spending elsewhere. To avoid losing productivity, either use a deck wash or set your pressure washer to a low pressure. 

The Right Supplies

Your local Sherwin-Williams store can help supply you with all your product needs when it comes to your next deck finishing project, no matter what stage of the process you’re in.

For those seeking a stain and sealer remover, Fiorilli recommends SuperDeck Stain & Sealer Remover—which can remove latex and oil-based stains, toners, clear finishes, and some solid color stains—and then pairing it with SuperDeck Revive Deck and Siding Brightener.

“It’s a two-step process,” Fiorilli says. “Revive neutralizes the wood. It makes sure you wash away all of that stain and sealer remover off the deck. That way, when you put the new stain over the top of it, there’s no stain or sealer remover remaining to damage that topcoat or the new stain.”

Because the focus for Stain & Sealer Remover is covering large areas—rather than looking good—Fiorilli recommends using a Best Liebco deck scrub brush attached to a Purdy POWER LOCK™ extension pole for application.

For the actual finish itself, Fiorilli recommends using the SuperDeck® product collection of stains, sealers, and coatings, which combine a beautiful finish with long-lasting performance and protection.

“Our SuperDeck coatings come in both water-based and alkyd/oil-based versions,” Fiorilli says. “There’s a lot of different options designed to suit whatever your project needs are. And depending on the product you choose, there are specific brush or roller cover recommendations on our data pages for each product. You can find that online or talk to the expert employees at your local Sherwin-Williams to find the perfect applicator for your project.”

As a general rule, Fiorilli says he recommends Purdy® Syntox™ brushes or Purdy® White Dove™ roller covers for SuperDeck waterborne products. For oil-based products, he recommends using a Deck & Siding Brush or a Purdy® White Dove™ roller cover. For more specific recommendations, check out the Sherwin-Williams Brush & Roller Guide.

Finishing Well

During the application process, Fiorilli says there are three common mistakes he sees even experienced painters make.

First, he says, it’s important to always back-brush when finishing decks. Back-brushing results in a more even finish and ensures you’re really pushing that stain into the wood.

Second, taking breaks during the project can result in uneven finishes.

“You’ll see painters stop in the middle of a deck, and they’re not working off these wet edges,” Fiorilli says. “You typically will see that edge where you stopped and then started again, and it’s really hard to fix that and to blend it in. If you’re going to start the project, you want to complete the project, or at least break it into pieces where there’s a clear break—where it’s not going to be visible where you stopped and started.”

Finally—and perhaps most significantly—Fiorilli finds that many painters will overapply stain. That results in both a waste of product and an inferior finish.

“I see this a lot where the painter’s just trying to get the color a little darker, so they apply it really heavy,” he says. “This typically happens with a semi-transparent. But a stain is designed to penetrate, and what happens is then it doesn’t dry properly or it takes a long time to dry. In some cases, maybe it gets rained on, or it just stays tacky and never really dries properly. So it’s important not to fall into the trap of overapplication.”


Approach your next deck finishing job with confidence with expert insight and premium products from Sherwin-Williams. For more resources and advice on decks, check out the free resource guides and tutorials from Sherwin-Williams.