How to pressure wash a deck before staining

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If you have a deck that’s been neglected, it’s time you cleaned it, stained it, and made it look amazing again. I’ll show you the exact steps you need to take to ensure your deck is prepared before applying your deck stain.

By showing you how to pressure wash a deck before staining, I will make sure that your deck looks it’s best and that the stain provides the protection you expect for years to come.

You may be thinking that you can do this by hand, and for the most part, that’s true, but hand-scrubbing just won’t do the job of deep-cleaning, not like a power washer will. That said, by using the wrong power of pressure washer you can end up ruining your deck, this is a tool that has enough power to etch a pattern into solid brick, so you can imagine what it’ll do to your wood deck.

While a pressure washer is a powerful tool, in the right hands, it can be gentle enough to wash siding. Just remember to use the right pressure setting, nozzle tip, and maintain a good distance from the deck. Otherwise, you risk deeply etching the wood or even causing the wood fibers to splinter.

Equipment you’ll need

  • A pressure washer with a rotating tip or fan tip
  • Deck cleaning solution (Krud Kutter, Deck & Fence)
  • Sheets of plastic (optional)
  • Random orbital sander (optional)
  • Deck brightener/stripper (optional)
  • Sandpaper (optional)

What is staining a deck?

If you’ve never stained your deck before, perhaps this is a new home for you, and you’ve inherited a deck, or you’ve decided to add some decking to your home.

It doesn’t matter; we’ve all been there, something new is in your life, and you need to learn the whats and the hows.

Wood Stain With A Paint Pad On Wooden Patio Floor

A deck stain is a protective coating that you apply to the wood. It protects the wood and also helps to bring out the dramatic natural colors and wood textures. I recently applied a varnish to a newly constructed external door, it looked good before, but after, the wood grain just shone through; it really made that door sing.

This is the same for deck stains; it can really enhance the textures and the grain in your decking. By staining your deck, you enhance its beauty and the beauty of your house. Plus, it adds protection, which will extend the life of your deck.

Typically a wood stain will contain three primary ingredients: The pigment, a binder, which will usually contain the commercial wood stain, and a solvent.

These ingredients are the same regardless of your stain is water or oil-based; they offer you a wide variety of colors, which can darken the wood if you want or enhance and highlight the natural grain and patterns.

You can also paint your deck; the choice between a stain or paint is really down to personal preference, though with paint, you are going to hide that natural wood and it’s grain pattern, while a stain works as more of an enhancing, complementing what the wood is already offering. You can paint over the stain (do your research first). You can’t stain over paint, that is unless you trade your pressure washer for a sandblaster, So I suggest if you are on the fence, go with a stain first.

Before you get started

Or rather before you bust out the pressure washer, make sure to clear your deck of any furniture or barbeques; if you have any railing that can be removed, remove it.

Once everything is removed, inspect your deck and look for bad boards; anything rotten or falling apart should be removed and replaced with a new board.

If the decking is old, I highly suggest pre-soaking the deck with water; if it’s a hot day, it’s worth re-soaking over the space of an hour to ensure that the wood is saturated and the dirt and grime are softened.

Make sure to wear protective clothing such as safety goggles to ensure any debris or chemicals don’t get into your eyes.

Cleaning Terrace With A Pressure Washer

Instructions

1. Selecting the pressure washer tip and pressure settings

Before you start pressure washing your decking, you need to ensure that you’ve chosen the correct nozzle tip; I suggest starting with the 30-degree tip and choosing a pressure setting somewhere between 500 to 600 pounds per square inch (PSI), this perfect for softwoods such as pine or cedar. However, if you have a harder wood, these can tolerate high pressures, even up to 1200 PSI.

You can use a rotating nozzle tip, but you have to take care, as these tips tend to produce extreme PSI ranges and could cause damage to your decking.

I suggest before you get stuck into the task that you find an area of decking, an inconspicuous area such as a stair tread, to test the pressure out on first; the upside to using a stair tread is if you accidentally etch the wood, replacing a stair tread is easier and cheaper to replace than an entire deck board.

If you don’t have a pressure washer then I highly suggest taking a look at these which are some of the best entry level pressure washers.

2. It’s time to clean your deck.

Before we get to applying a stain, we need to remove any dirt; if you’ve followed my advice in the before you get started section, then your decking is nice and wet.

Start by using a low pressure, somewhere between 500 and 600 PSI, starting with the stair treads, increase the pressure incrementally, only going as high as you need without causing any damage or etching the wood surface.

Before you pull the trigger on your spray wand, make sure to keep the nozzle tip a few feet away from the deck surface, then lower the wand closer to the decking but aim not to get any closer than 12 inches above the surface. Clean your decking with water only at first, using a sweeping motion, try not to pivot your arm, which will result in an inconsistent distance between the spray tip and the deck surface. You really want to maintain a consistent distance by moving your arm laterally back and forth.

I suggest cleaning the boards from your house backward out. Work the grain by feathering the spray lengthwise, parallel to the deck boards, and making sure to overlap each area slightly. You are aiming to achieve an even clean with no hot spots or visible cleaning edges.

Try not to move in small swings; you want to cover as much as the board as possible; this will reduce the likelihood of cleaning edges.

3. Apply a deck cleaner or chemical stripper/brightener

If your deck is badly darkened, or stained with grime and mildew, then using your pressure washer alone may not be enough, you may need to bring in a cleaning solution. I suggest using something such as Krud Kutter Deck & Fence cleaner.

If you want to brighten your deck, then look for a solution that includes sodium hydroxide, specifically look for a product that is designed for brightening deck wood and also look for one that’s also for use in a pressure washer.

Ensure you mix the solution as per the recommendations made by the manufacturer, apply the stripper solution to the deck in the same way you did the plain water, then rinse the solution away by pressure washing with plain water.

I’ve found that stripper/brightener products tend to cause the wood fibers to roughen up, so it’s wise to sand the deck afterward before re-staining or sealing the wood.

Do note that chemicals in deck strippers/brighteners are toxic to plants and vegetation, so I highly suggest that you shield shrubs, grass, and garden plants with sheets of plastic before using a stripper with a pressure sprayer.

4. Sanding after washing

This is an optional step. But when power washing a wood deck while when done correctly, you won’t ruin the wood or etch or erode the softwood fibers; when the wood gets wet, those wood fibers may become raised, which results in a rough surface. This can be a problem with handrail; these fibers can lead to splinters; make sure the wood is completely dry. Then you can sand these fibers away.

If this is a problem, you have a few options, firstly. If you did a great job when power washing, there will be minimal damage, if any at all, and you are just cleaning your deck, then you will probably get away with no or very little spot-sanding here and there.

But if you are refinishing your deck, then you will need to sand the entire deck to create boards with little to no splintering. Sanding also opens up the wood’s pores, helping the wood absorb/soak up the sealer or stain consistently.

A note, when you sand, do not use very fine sandpaper, as this can clog up the pores of your deck, which will prevent the stain/sealer from soaking in. When sanding your handrail, use no finder than 100-grit sandpaper. For your decking surface, I suggest a 60-80 grit sandpaper.

Having done this a few times, I suggest using a random orbital sander with a 5-inch sanding pad.

Wrap up

If you’ve followed my advice on how to pressure wash a deck before staining, then hopefully, you are either completely set, ready to crack on with the job, or you’ve successfully completed it, and you now have an awesome looking deck.

Last update on 2020-11-27 / Affiliate links / Images from Amazon Product Advertising API

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