Stains and finishes

Since the elements will shrink and swell wood over time, we recommend applying a stain or finish to redwood to minimize the problems of cracking, raised grain and mildew growth. As with everything else, we suggest using the highest-grade product you can afford, and one that matches the quality of the wood you’re using.

Varieties

Like fasteners, finishing stains come in many types and a rainbow of colors. Stains commonly come in two basic formats: oil based or water based. Breaking it down even a bit further you will find decking stains labeled as: clear, transparent, semitransparent, semi-solid and solid. As the names imply, the further down the list you travel the more color pigments are added to the product and the more similar they become to full coverage paint. These products (except for clear) all come in a rainbow of colors. Try small test patches on scrap, clean pieces of redwood decking material to learn how the final product will look on your deck. Always follow the manufacturer’s recommendations.

Selecting the best one

A penetrating finish applied to wood decks provides better overall performance and is easier to reapply than a film-forming finish (e.g., paint, solid-color stain). In addition to the continuous shrinking and swelling of the wood caused by changes in the moisture content, film-forming finishes are subjected to excessive wear, especially in high-traffic areas. For these reasons, penetrating finishes, not film-forming finishes, should be used on wood decks.

Varnishes and Polyurethanes

Since they will often crack and peel when used in exterior applications, we do not recommend using either varnishes or polyurethanes for your deck or other outdoor projects.

Preparing the wood

New boards that are laid down and fastened to the deck’s substructure need a short period of time to adjust their moisture content to match the humidity of their environment. If you decide to apply a finish, try and do so about three weeks to one month after the deck boards are installed. Wait for a sunny, though not too hot, day and apply your stain carefully, evenly and following all recommended practices and instructions provided by the manufacturer. Don’t wait too long, though. Letting the boards sit without any finish for months and months may prevent a good solid bond with a finishing product.

Application

You can use a brush, roller, or hand-compressed sprayer to apply your stain. Follow recommended practices and instructions per manufacturer to achieve desired results. Be sure to apply your finish to all sides of the board: face, sides, bottom and ends. And always remember that wet redwood will not hold a finish as well as dry, acclimated redwood. Waiting for the right time will pay off down the road.