A deck is a special part of your outdoor living space. A well-maintained deck should last for years. Keep it looking its best with the right deck cleaners and stains.
Prepare for Deck Maintenance
Wood left exposed to sun and moisture will quickly begin to degrade. Leave your deck untreated and you can expect it to turn gray with age. In addition, the decking boards are likely to cup, warp and split. Ignore the problem for too long and you'll have to make major repairs — or even replace sections of deck.
Deck sealing is a three-part process.
- Remove any old stains or coatings.
- Clean the wood.
- Seal it against weather damage.
If the deck has never been sealed before, you won't have to strip it, but brand-new wood has special pre-stain preparation needs. New decks need to weather for several months before sealing. The new boards usually have a high moisture content and the wood surface is too smooth (due to milling) for any stain to penetrate. After the new wood has weathered, follow the cleaning and sealing steps above – with one difference: apply only one coat of stain to a new deck.
If your deck has been sealed before, use the water test to see if it's time to seal it again.
- Drizzle some water onto the boards.
- If the water beads, the wood is still sealed and protected.
- If the water is absorbed into the wood, it's time for a treatment.
Remember to test several different areas of the deck. High-traffic spots are likely to wear down before corners and rail spindles.
Wear rubber gloves, closed-toe shoes, a long-sleeved shirt and long pants when applying deck chemicals to minimize the chance of skin irritation. Also, wear safety glasses to protect your eyes from back spray. Follow all manufacturers' safety instructions.
Stripping Your Deck of Stains and Coatings
Stripping is essential for creating an even surface for the new sealant. If the high-traffic areas of your deck have worn down, but there's still sealant remaining in other areas, strip the entire deck before you re-stain. Stripping is even more important if you're changing colors. Traces of an old color left underneath will affect the way a new color appears. Stripping is most important if you're changing colors. Traces of an old color left underneath will affect the way a new color appears.
Depending on your current deck finish, choose a stripper that's formulated for:
- Removing clear and toned finishes and sealers, requiring less stripping power
- Removing semitransparent or opaque stains, requiring more stripping power
Consult the manufacturer's instructions to determine which stripper is right for your project.
Deck Cleaning Materials
After the deck is free from existing stain or sealant, clean it. (If you didn't have to strip the deck, this will be your first step.) When looking at deck cleaners, you'll probably find one of these active ingredients:
- Chlorine bleach, which appears on the label as sodium hypochlorite or calcium hypochlorite. These chemicals do a good job getting rid of mildew.
- Oxalic acid, listed in the ingredients is particularly effective at removing tannin and iron stains — a particular consideration with cedar and redwood decks.
- Natural solutions and cleaners are free of bleach, acid or phosphates. These tend to be biodegradable and safer to use around landscape plants.
If you own a composite deck, use a specially formulated product (or dishwashing detergent and water). Wood deck cleaners are too strong and may cause composite materials to fade.
Choosing a Deck Stain and Sealer Product
There are four main options for deck stains: clear, toner, semi-transparent and solid / opaque. As a general rule, wood that's older and more weathered requires a more solid or opaque stain to cover imperfections. Most sealers also provide waterproofing and sealing protection. The best sealers penetrate the wood the most to provide the most protection. Look for an oil-based product that's mixed with latex for easy cleanup.
Clear finish provides basic protection and allows the wood to turn gray naturally, though without splitting, warping, cupping or cracking.
Wood toners are similar to clear water repellant, but they include a hint of color to help maintain or restore the natural beauty of wood. They provide similar levels of protection against splitting, warping, cupping and cracking.
Semi-transparent stains are subtle and show the grain and texture of wood. These stains contain pigment that protects against sun damage better than a clear preservative. Oil-based semitransparent stains provide the most protection, better color retention and longer life.
Solid / opaque color stain provides a richer color but still shows the texture of the wood. These stains are also used on fencing and outdoor furniture. Some are suited only for vertical surfaces, so check the label when shopping. An alternative to stains or sealers is applying a resurfacer or restoration product. These finishes are like a very thick paint. Applied with a brush or roller, they cover deck boards and do not show wood grain. Tints can be added to match your home exterior or deck railings.
An alternative to stains or sealers is applying a resurfacer or restoration product. These finishes are like a very thick paint. Applied with a brush or roller, they cover deck boards and do not show wood grain. Tints can be added to match your home exterior or deck railings.
The frequency of re-treating or recoating varies by product. Read the label for guidance.
Deck Maintenance Considerations
Before you tackle a deck restoration, there are few other things to consider:
- It's tricky to work backwards on the spectrum. For example, if your deck is currently covered in an opaque stain, it will take a great deal of stripping and surface preparation to ready it for a clear or wood-toned stain. It's usually easiest to continue with solid / opaque coverage.
- The more opaque a stain, the quicker it will show wearing and weathering. A solid stain might need reapplication every year, while a clear or wood-toned treatment probably will last longer.
- Darker colors, particularly solid / opaque and semi-transparent stains, will absorb heat more easily. They could make the deck uncomfortable for barefoot walking.
- For a decorative look, select two or more colors that work together for decking and rails, post caps, stencil work, etc.
- Make sure to choose a specially formulated deck stain or sealer to repel water, resist mildew and prevent fading in high traffic areas.
- Sealers and stains are either water-based or oil-based. Water-based products offer easier cleanup and less odor; oil-based products tend to penetrate deeper for longer-lasting stain.
- When choosing a stain, remember that the finished color varies based on the wood itself. If you're applying a new stain over an old one, choose a color that's similar to or darker than the original. Test the color in an inconspicuous area to ensure proper color.
- Coverage varies depending on type of surface and type of stain. In general, two thin coats better than one thick coat.
Shop Stains and Sealers
Deck Maintenance Accessories
Your deck restoration shopping list will contain more than just cleaner and sealer. Here are some other products that will make the job easier:
- A pump-action sprayer to apply cleaning solutions. You can buy one labeled deck sprayer or garden sprayer, but don't use it for spraying your garden once it's had deck cleaning chemicals in it.
- A stiff brush on a long handle for scrubbing. Don't use one with metal bristles, because it might damage the wood.
- A paint roller on a long handle for spreading stain or sealant. Look for a 1/2 in. or 3/4 in. nap.
- Paintbrushes made to apply the stain you have chosen.
- Plastic tarps to protect nearby plants from overspray.
- Tape to mask off areas that you don't want to stain.
- Sandpaper to smooth rough surfaces.
- Protective gear such as gloves, hand and eye protection.
- Garden hose for cleaning and rinsing.
- Pressure washers to quickly remove dirt, mold and mildew with more power than a garden hose.