How to Refinish a Wood Deck
A beautifully refinished wood deck not only looks great and extends the life of the wood, but it also may help improve the real estate value of your home and make it more appealing to potential buyers. The complete refinishing process for a wood deck may involve several individual steps, including:
- Inspection and repair
- Power washing
Not all refinishing projects will include all steps. For example, deck surfaces do not always need to be sanded, and some decks are simply sealed and are not colored with stain. In most cases, however, the stain itself is the sealer, and it includes some pigment to even out the wood's coloring and provides additional protection against sun damage.
In any case, a professional-looking deck refinishing job can be done in a weekend or two and will transform a drab, tired old wood deck into a vibrant beautiful entertainment area ready for a celebration barbecue.
Before You Begin
The first step in your wood deck refinishing project should be a thorough inspection, looking for any loose surface boards or structural component problems, including rotting or severely split wood. If you do need to replace a damaged or rotten deck board or other components, make the necessary repairs before beginning the overall refinishing project.
The exact approach to cleaning a deck will depend on its current finish and what your goals are for refinishing.
If you have a varnished or painted wood deck and want a stained wood deck, you must first strip the paint or varnish off the deck surface using a chemical stripper. This will be followed by cleaning and sanding before applying a new stain finish. If you are simply painting, however, the process is relatively simple: clean and sand, then repaint.
If your deck is finished with a clear sealer or a transparent or semi-transparent wood stain, then you can just clean the surface with a wood deck cleaner, without bothering with paint stripper. It's recommended that you use an oxygen-based wood cleaner designed to remove mildew stains and graying caused by sun exposure while it cleans the wood of dirt and deposits.
What You'll Need
Equipment / Tools
- Power washer
- Garden hose and sprayer (optional)
- Random orbital sander
- Shop vacuum
- Paint pad applicator
- Deck cleaner/brightener
- 60- to 80-grit sandpaper
- 80- to 100-grit sandpaper
- Wood stain
- Clean rags
Power Wash the Deck
Deep-cleaning of the wood is an important step in refinishing, but you must be careful here. Power washing can be a very effective way to deep-clean a deck, but it can also easily damage the wood if it's done improperly. Using too much water-jet pressure, holding the spray nozzle too close, or using the wrong sprayer tip can etch the wood and possibly ruin some deck boards.
When using a power washer to clean wood, always use the lowest pressure that still provides effective cleaning. Pressure for softwoods, such as cedar or pine, should be at about 500 pounds per square inch (psi) to 600 psi; harder woods may go higher, but no more than 1200 to 1500 psi.
If you don't want to use a power washer, you can simply hose off a deck with a garden hose and a strong spray nozzle, then scrub the wood with deck cleaner/brightener, following the manufacturer's instructions.
Sand the Deck
Sanding a deck before refinishing is recommended if the boards are rough and/or badly sun-damaged. If the main deck surface is in relatively good condition, you may choose to sand only the handrails and perhaps do some spot-sanding in damaged or discolored areas. Smooth handrails are important for preventing splinters.
Sanding a deck is easiest with a random orbital sander, but the correct sandpaper grit is essential to good results. Sandpaper that is too fine will leave the wood pores packed with dust that will prevent the stain from soaking in. Sanding with a paper that is too coarse can damage the wood, especially with softer woods such as cedar.
Use 60- or 80-grit sandpaper on the main deck boards, and use 80- or 100-grit on the handrails. Vacuum all surfaces thoroughly after sanding. Don't wash the deck again, as this will raise the wood grain and roughen the surfaces you just sanded. If it rains in the meantime, simply let the deck dry out completely before refinishing; you don't need to sand again.
Select a Wood Stain
While once it was common to first stain wood then apply some kind of clear surface sealer over it, today's products are generally one-step applications—penetrating stains that both color the wood and soak in to protect it. There are also simple clear sealers that do nothing more than penetrate and seal the wood without changing the color. However, these provide less UV (sunlight) protection than pigmented deck stains.
Among the products that stain, you will find semi-transparent stains that allow the wood grain to be visible through the stain as well as opaque stains that color the wood, more like a coat of paint, hiding all wood grain. There are also water-based and oil-based varieties. The easy cleanup offered by water-based stains may be attractive, but most experts agree that water-based exterior stains do not last as long as oil-based products and do not soak into the wood fibers as thoroughly.
Most people find the best results with a quality oil-based, penetrating, exterior semi-transparent stain. You may have to look beyond the big box home improvement center and go to a professional paint store to find this product, but it will be worth the effort and expense.
Also remember that the actual color of the stain, once applied, may differ from the samples or brochure. Make sure to confirm how the stain will look on your wood species before you commit to a large quantity. Buying a small sample of stain and testing it on your deck is a good idea before you purchase it by the gallon.
Choose the Right Brush
It's usually best to stain/seal the main deck surface with a paint pad applicator, while paintbrushes are required for detail work. It is best to use a natural-bristle brush if you are using an oil-based product, and a synthetic-bristle brush with water-based stains. You will likely need a few different brush sizes.
Apply the Stain
Staining the deck is where you see all your hard work come together. Make sure the deck remains completely dry for about two days before staining, especially with oil-based stains. Any moisture in the pores of the wood will prevent proper absorption of the stain.
Start with the handrails and work your way down to the deck boards. Use a variety of brush sizes to stain the small areas, such as handrails, balusters, and trim boards, and finish all the brushwork before moving on to the decking surfaces.
The surface decking boards are best stained with a flat paint-pad applicator. This ensures fast coverage of a large area, helps you easily maintain a wet edge, and results in a nice, even application of stain. Apply the stain liberally with the applicator, let the stain soak in for a short time (as recommended by the manufacturer), then wipe up any excess with a rag. Do not leave pools of stain to dry on the surface.
Dispose of oily rags properly to prevent a fire hazard.
Watch Now: How to Properly Pressure-Wash a Wood Deck
Safety With Oily Rags Wet With Flammable or Combustible Liquids. National Fire Protection Association.