When you first painted that deck it looked great. Now, years after the job, the paint is weathered and peeling. Perhaps you are contemplating replacing the deck. Maybe you are about to call a contractor to get an estimate for stripping the deck back down to its natural finish. Before you do that, consider doing the job yourself. Here are some methods available as well as tips to help you get the best possible result
Decide what kind of paint is on your deck
The first thing you must determine is the nature of the paint. Is the paint an oil based exterior paint or a latex? Latex lays on top of the wood which makes it easier to remove while an oil based paint will be much tougher to remove. If you were not present when the paint was applied and are not sure of the kind of paint used, a simple test will tell you the type of paint you are dealing with. Put a small amount of alcohol on a rag or cotton swab and rub this over the paint. If the paint comes off, it is latex. If it does not, you are dealing with oil-based paint. Of the two types of paint, latex is by far the easiest to remove.
There are two methods to remove paint on a deck; chemical and mechanical. Chemical methods involve fairly caustic chemicals that can be applied by sprayer, brush, and roller. Mechanical methods include power washing, sanding and planing. Using a combination of these methods will yield the best results. Most contractors prefer a combination of chemical and power washing. The chemicals used to strip latex paint are caustic and salt based and can come in either a gel or thinner based form suitable for spraying. Usually, a gel-based stripper is more effective but requires application by roller and brush which is more time consuming. However, a gel based stripper is most effective on vertical surfaces such as rails and box sills due to its ability to cling. Anytime you are using a chemical, be sure to wear protective gear. Wear goggles, rubber gloves and a dust mask.
Work in ten foot by ten-foot sections as you apply and remove the stripper. After allowing the stripper to work for the recommended time, use a power washer set on a lower pressure to peel away the softened paint and rinse away the salt-based stripper. You want to be certain that you rinse thoroughly so that no stripper remains to foul the new coating you will apply to the deck. A thinner stripper suitable for spraying may be effective for decks that have a minimal amount of paint to remove. Simply spray on and wait the recommended time. Then pressure wash the chemical away. Do not use hot water. Cold water is just as effective and hot water may damage the wood.
Oil based paints and latexes that have been on the deck a long time may require additional mechanical methods for removal. Sanding is the next step in this operation to remove paint. Use a belt sander. The idea is to take as little of the wood surface as possible when removing the paint. If spots remain on the wood, planing is the final step in paint removal. This will require the removal of the boards and running them through a planer. Planing the wood will reduce the dimensions of the boards, however, and should only be used sparingly in the most difficult cases.
When you are finished stripping the deck you will be ready to stain or seal it. It is critical that you have rinsed away the stripping agent before doing this. The stripper will continue to work on the new coating if all of it has not been removed. Clean and store away all tools you have used and properly dispose of brushes and roller covers in an EPA approved manner.