Deck Staining and Maintenance

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If you are considering branching out into the deck staining business, it will pay to be informed about deck stains, both for customer education and for your bottom line. Without being exhaustive, let’s look at the main characteristics of deck stains.

Acrylics have become very common in the deck stain market in recent years because of their longer durability. Like acrylic paints, acrylic deck stains form a film on top of the wood and don’t penetrate much. Excellent prep is necessary for reasonable performance. Label claims vary wildly, which confuses everyone, and actual performance rarely lives up to claims. Getting four to eight years on a controlled exposure test fence is one thing. Real life, with foot traffic, sliding furniture, dogs, snow shovels, etc., puts tremendous strain on these surface coatings, and once that thin coating is cut or broken, peeling is not far behind. Peeling of acrylic stains should be anticipated, and when it comes time for a maintenance coat, sanding will be required.

Drying oils and alkyds have maintained their status as go-to stains for decks. Oil-in-water emulsions have come a long way in the last decade, and many quality stains are available. The oils and alkyds in these stains penetrate the shallow surface of the wood, leaving a thin film on top. They are more forgiving when less-than-ideal surface prep is done and are fairly easy to apply. The UV resistance of oils and alkyds is good but won’t last as long as acrylics. With these types of stains, there are two failure modes: cracking and peeling or gradual erosion. When it comes time to restain cracking and peeling require sanding. Certainly erosional failure is the easiest to restain as prep can be done with a powerwasher or even a hose and stiff broom. Erosional stains need to be maintained every one to two years, but the ease of recoating them keeps them popular.

Nondrying oil stains are becoming less popular but are still widely available. These oils soak deep into the wood, leaving only colorant and a little oil at the surface. The oils make the wood water-resistant, but the surface pigments wash away, yielding little UV protection for the wood. As a result, reapplication once or even twice a year is necessary to maintain protection. The oils’ biggest advantage is that they will never peel. What most customers do not anticipate is that the water-repellent qualities of these oils also mean that no water-based stain can be reliably applied to that deck in future years, limiting future stain possibilities.

Understandably, each of the above types of stains has its fans, and each has advantages in different applications. Acrylics are great for siding and decks that are only lightly used. Eroding oils and alkyds are great for high-traffic decks and fences, as they are easiest to maintain. Nondrying oils can be good on shake roofs.

Transparency is another place where deck stains vary. Often, customers will have an idea of what they want but don’t understand that their choice will determine the maintenance intervals. Clear coatings look great at first, but they offer the least UV resistance and fail quickly. Transparent and semitransparent stains add some color to the wood, last much longer than clears and highlight the natural beauty of wood grain. Opaque stains offer the most UV resistance and last the longest, but they hide the beauty of the grain completely, as well as develop problems (like rot!). With that information, we can often guide customers toward semitransparent stains in darker colors.

As with painting exteriors, surface prep takes longer than staining. Prep varies for different circumstances. New wood should be lightly sanded with 80- to 100-grit sandpaper. Maintenance coats of an erosional stain or nondrying oil can be prepped with a light pressure wash or hose and broom. When changing from one stain to another, or any time peeling stain or gray wood are present, sanding or chemical stripping/pressure washing is required to get down to fresh, bare wood. Sanding is preferred, as it’s faster and leaves the ideal surface for staining. Chemical stripping/pressure washing may seem faster, but texturing, discoloration, splinters, damage from chemicals and time for the wood to dry before staining combine to make that method slower, more expensive and overall less desirable.

When re-staining a deck, be aware that unknown previous stains can cause issues, especially if they contained waxes, silicones, or non-drying oils. This is especially true when switching to water-based stains. Test prepped wood with a few drops of water. Wood that is ready for staining will absorb the water quickly. If water beads up without soaking in, it’s time to re-evaluate both stain type and necessary surface prep.

All decks stains need to be maintained. The timing depends on the type of stain and wear and tear. It’s best to maintain the stain as it starts to wear, rather than waiting until the wood goes gray, to minimize prep and on-going maintenance costs. After staining a deck, offer your customer estimates on future work based on the condition of the stain. Give one estimate for a quick power wash and re-coat before the stain goes bad, and another estimate if the deck needs to be completely sanded and re-stained. Once the customer sees the difference in price, they’ll be more inclined to buy in to a regular maintenance program. This means steady income and marketing gold: positive word of mouth from satisfied customers. APC


Jim Barnes is the senior stain Chemist at Sashco, Inc. He can be reached at info@sashco.com.

 

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