Ready to Paint Your Deck? Learn How to Prime Pressure Treated Wood First

Summer is right around the corner, and you may be thinking about giving your weathered deck a fresh new look with a nice coat of paint. Painting a deck can completely transform an outdoor space. However, when it comes to prepping and painting exterior wood, pressure treated lumber requires some special considerations compared to standard boards.

Pressure treated wood contains preservatives that help protect it from rot, fungi, and insects. But these same chemicals can cause adhesion issues for paints and coatings. Without proper prep work, you're likely to end up with peeling, blistering, or faded paint in no time.

Fortunately, there are steps you can take to ensure success painting your pressure treated deck. The key is patience - letting the wood properly dry and cure, cleaning thoroughly, and applying a quality primer prior to topcoating.

This guide will walk you through the entire process of prepping and priming pressure treated lumber. Follow these tips and you'll have a beautifully painted deck that maintains its color and integrity for years to come.

Wait for the Wood to Dry Thoroughly

Fresh pressure treated wood contains a lot of excess moisture. If you paint too soon, the paint won't properly adhere as the wood continues drying out. Trapped moisture tries to escape through the paint, causing bubbles, peeling, cracking, and early coating failure.

Here are some tips for determining when pressure treated wood is ready for your primer and paint:

• Allow new PT wood to dry out for at least 6 months before considering painting. Longer is better.
• Check for moisture using a moisture meter. Look for readings of 15% or less before priming.
• Do a rain test - sprinkle water on the wood. If it beads up and sits on top, the wood is likely ready. If the water soaks in, wait longer.

It's essential not to rush this step. Remember, pressure treated wood takes longer to dry out and release any trapped chemicals. Don't rely on a simple visual inspection. Use the objective moisture testing methods above to be confident your wood is adequately cured and stable enough for priming and painting.

Clean the Surface Properly

Once your pressure treated wood is dry, you'll need to clean it prior to priming and painting. PT wood often has a waxy surface layer called mill glaze as well as dirt, dust, grease, and other contaminants that can impede proper paint adhesion.

Here are some tips for effective cleaning and surface prep:

• Use a commercial deck cleaner formulated for wood preparation prior to staining or painting.
• For stubborn areas of mill glaze, use a power washer on a low pressure setting to thoroughly clean and prepare the wood surface.
• Always rinse cleaned areas thoroughly and allow to dry completely before priming.

Proper cleaning removes the stabilizing chemicals that may be concentrated on the surface while also providing the ideal surface profile for your primer and paint. Don't neglect this step - your coating results depend on it!

Choose the Right Type of Primer

With pressure treated wood properly dried and cleaned, now you're ready to apply primer. Priming plays a crucial role in preparing the wood for paint. It seals the surface, blocks stains, and allows for superior paint adhesion.

When it comes to choosing a primer, you have two main options:

• Latex primer - Water-based acrylic primers are generally recommended for priming pressure treated wood. Look for a high-quality exterior wood primer.
• Oil-based primer - Alkyd primers using solvents tend to provide better penetration and sealing of treated wood. They also offer excellent stain blocking.

Many experts suggest using an oil-based primer made specifically for application on pressure treated lumber. The oil penetrates deeply while providing a sound base for latex topcoats. Examples include Zinsser B-I-N Primer and KILZ PREMIUM Primer.

Whichever route you take, check that the primer is rated for use with pressure treated wood. The preservatives and chemicals used in PT lumber can react poorly with some solvents and coatings not designed for compatibility.

Apply Primer in Thin, Even Coats

With your primer selected, you're ready to start applying it to the wood. Here are some tips:

• Stir or shake the primer thoroughly before using.
• Apply using a quality bristle brush, working the primer into the wood grain.
• Apply thin coats and avoid runs or drips which can compromise adhesion.
• Allow each coat to dry per the manufacturer's instructions before re-coating.
• 2-3 thin coats of primer are typically needed to properly seal pressure treated wood.

Take care to apply the primer smoothly and evenly. Pay extra attention to the end grain which tends to readily soak up paint. Follow the above best practices, allowing proper dry time between coats. This ensures the primer has a chance to adhere and cure fully before adding another layer.

Finish with Exterior-Grade Paint

Once primed, you're ready to apply exterior paint. Here are some quick tips for this final step:

• 100% acrylic latex paints provide best performance and durability on outdoor wood.
• Choose a paint designed for decks, exterior siding, fencing, etc.
• Use a paint that is compatible with your primer - usually latex over latex and oil-based over oil-based.
• Two finish coats are recommended for best coverage and protection.

Following the manufacturer's instructions for dry times and recoat intervals will result in a professional, long-lasting paint job. Maintain a consistent coating process throughout the priming and painting stages.

Extra Tips for Success

Keep these additional pointers in mind when priming and painting pressure treated lumber:

• Prime and paint all sides of the wood, not just the surfaces facing out.
• Inspect for early primer failures like poor adhesion, cracks, bubbles or tackiness which indicate problems.
• Clean and recoat painted wood as needed to maintain its protective barrier.
• Watch for signs it's time to reprime and repaint such as wear, fading, and flaking.

Proper prep work, high quality primer, and the right exterior paint combine to offer outstanding performance and durability for painted pressure treated wood projects. Follow these best practices and you'll avoid frustration and enjoy beautiful results.

Painting pressure treated lumber brings its own set of challenges compared to standard wood boards. The treating chemicals can interfere with proper paint adhesion if you don't take the right steps to prep and prime the wood.

Allowing adequate dry time, cleaning thoroughly, and applying compatible quality primer are all vital to success. Topcoating with exterior grade acrylic latex paint then provides maximum protection and beauty.

While it requires attention to detail, you can paint pressure treated wood to look amazing for years to come. Just remember to have patience and prime before bringing out the paint. Follow this guide and you'll avoid peeling, cracking, and blistering as you enhance your exterior living spaces with durable, rich colors.