Protect Your Wood Deck With Proper Preparation and the Correct Stain or Sealer!
by Tom Daniels of Cabot Woodcare Products
Decks are extremely vulnerable to the harsh elements of nature as well as man-made abuse. Acid rain, ultraviolet light, heat and standing moisture in the form of rain, dew, frost, ice or snow, all can cause damage to your deck. But foot traffic, barbeque grills, food and drink spills and water from a pool or sprinkler system also can be harmful and jeopardize the longevity and appearance of your deck.
Homeowners must take precautions to protect the investment made in their deck and minimize or eliminate these problems as much as possible. Selecting a product specifically designed for deck protection, combined with proper product application and a few maintenance steps will help put an end to deck hassles.
Preparing the Surface
Wood should not remain exposed for longer than three months without some form of protection. According to research from the Forest Products Laboratory, over-exposing unprotected wood for long periods of time can cause surface damage that reduces the wood's ability to hold onto applied stain or paint coatings. This can lead to premature coating failure.
Allow new wood two to three weeks to dry in order to bring the moisture content down to an acceptable level and to make sure the surface is dry and porous. This is especially important for pressure treated wood, as it is often times damp or wet at the core depending on treatment method used and amount of drying time. Some weathering of the wood is necessary if non-film forming finishes, such as stains and water repellents, are to penetrate the wood's surface and work effectively.
Whether staining old or new wood, inspect the surface for cleanliness, making sure it is free of mildew stains, dirt and other foreign matter. If the deck needs to be cleaned, scrub it with Cabot Problem-Solver© Wood Cleaner #8002, rinse with clean water and then allow two to three days for it to dry prior to staining.
Selecting the Correct Product
When selecting a stain, base your decision on aesthetic qualities, wood species and performance of the product.
1) Product Options
- Semi-transparent stains contain the lightest pigmentation to accentuate natural wood grain and character.
- Oil-based stains, like Cabot Decking Stains, penetrate deep into the wood and contain a tough alkyd resin for scuff resistance.
- Lightly-pigmented decking stains, which include Cabot's oil-based Clear Solution, bring out the full beauty of the wood grain while providing deep-penetrating wood protection. Although they are initially flat, translucent and amber-toned, Clear Solutions weather to a natural wood hue.
- Cabot's Solid Color Decking Stains also provides a tough, scuff- and water-repellent finish. The water-repellent qualities of these products protect the wood against the harmful effects of moisture, while the pigments in these stains protect the wood from the sun's damaging UV rays.
- Clear wood protectors and water repellents, such as Cabot's Clear Decking Stain, help to stabilize the wood by reducing the amount of shrinking, checking and cracking. Clear products provide good, short-term protection, and upon application of these products provide a “wet” look to the wood that will gradually weather gray. The degree of "grayness" depends on the wood species and the amount of sun exposure the deck receives.
2) Wood Species
- Pressure treated wood has a tendency to crack which will allow moisture to get into the wood. As moisture gets into the wood, the surface will expand and then contract as it dries out. Any film forming stains (such as a solid) will crack along with the wood and peel due to the contraction and expansion. To prevent these problems, use Cabot Decking Stains which penetrates deep into the surface to beautify the color and resist the peeling.
- Cedar and redwood contain natural tannins and resins that resist moisture intrusion so you don't have to stick to the Cabot Decking Stain. Cabot Solid Acrylic Decking Stains, Cabot Solid Oil Acrylic Decking Stain or Cabot Clear Solution are all viable options that will coat the surface depending on your opacity and desired look. These products are recommended for cedar or redwood that is less than two years old. For surfaces older than two years old, Cabot Decking Stain or Cabot Clear Solution is best for maximum adhesion to a weathered surface.
- Untreated fir requires a non-film forming product that penetrates well into the surface. Cabot Decking Stain, Cabot Clear Solution or Cabot Australian Timber Oil are all good recommendations based on the look and results desired.
Each deck product has its own features, benefits and limitations. For a distinctive look, mix equal parts of Cabot's oil-based Clear Decking Stain with a semi-solid pigmented Decking Stain in the desired color, to create a uniquely translucent type appearance.
Applying the Stain
Before you begin the staining process, check the weather forecast. The ideal temperature for applying stain is between 50© - 90©F. It also is best to refrain from staining if precipitation is in the forecast for the 12 to 24 hour period after coating. And always avoid application in direct sunlight. Before you get started, test a patch of wood to make sure you like the color and the dry time is normal be sure to blend all of the stain together to ensure color consistency.
More is definitely not better when applying stain. Over-application is a major source of problems with deck finishes. For an oil-based stain to be effective, it must be able to penetrate the wood's surface. Over-application leads to a buildup of material, forming a film on the wood which can ultimately peel or crack when exposed to excessive moisture. Applying too much of an oil-based product can produce an excessively waxy, sticky or slick surface, which interferes with the finish's ability to dry properly.
Untreated pine or fir absorbs stain products readily. Be especially careful not to saturate the wood and avoid excess pudding of the finish.
The recommended method of application is with a natural bristle brush because it works the oil-based stain into the wood fibers and cells more effectively. First, heavily coat the open end-grain of the boards. Brush three to four boards at a time, from one end to the other in smooth strokes. To avoid lap marks, make sure that the leading edge is kept wet and that the wet stain is brushed into wet stain. On new decks, it is important to only apply one coat of oil-based deck finishes.
For composite decking, which is made up of recycled plastic materials and wood, it is important to follow the manufacturer's recommendations. Penetrating and film-forming coatings can be used successfully, however, when using penetrating products, spread rates and longevity may vary due to the makeup of the composite materials used.
Once you have finished and stained your deck, maintenance is a necessity for keeping up the aesthetic. Clear finishes will require reapplication every six months to a year, pigmented finishes, like Cabot Decking Stains, will require inspection and reapplication every two to four years, and Cabot Solid Color Decking Stains need to be inspected every two to three years.
The major cost of most deck finishing projects is in the labor, so using a high quality, premium performance finish is the most cost effective. Whether protecting the deck from the scorching, summer sun or shielding it against the damaging effects of winter's ice and snow, a deck finish must be properly selected, applied and maintained to maximize the deck's beauty and longevity, and most importantly protect your investment of time and money.
The author, Tom Daniels, is director of marketing & business development for the Cabot brand and woodcare products. He also oversees the integration of interior wood stains and clear protectors. Daniels is a certified Coatings Consultant and serves on the executive committee of the Coatings Research Group Inc.