Deck Stain Options
Late this summer a friend decided to refinish her wood deck in the remaining days of sunshine. Once she completed the prep work of scraping and sanding, she was down to figuring out what type of stain to apply. Naturally a trip to the local box store was the first maneuver, that was a good way to open conversation about ‘what’s out there’, but created more questions than answered.
There is a difference between deck stain and deck sealer. The language manufacturers use varies slightly from one to the next potentially creating confusion. Generally, sealer imparts no color and simply seals against moisture and air and stain is more about adding ‘color’. However, these days, stain covers a broad range of utility. Here are some things I learned as I looked into the stain options for my friend:
- Stain will impart color and keep new wood looking fresh and will help to refresh old weathered boards
- Stains perform better than sealers in that the pigment actually helps to protect the wood from weathering from UV exposure
- Stains are often engineered to be effective with one coat
- Stains are available in oil-based, water-based and water-based epoxy-fortified mixtures
It appears that more pigment actually offers better protection from UV degradation. That said, stain comes in four versions: transparent, semitransparent, semisolid, and solid. Transparent stains appear clear to the eye, but actually do contain pigment. Look for the ingredient “transoxide”, this is a pigment that adds good UV protection without adding color, similar to how sunscreen works.
Semitransparent stains add a bit more color but allow the grain and texture of the wood to show. Semisolid stains actually conceals much of the woods natural character. Solid stain will offer the highest degree of protection given it’s high ratio of pigment, but will have a look that is not far off from paint.
Once you identify the level of pigment you want, the next thing to consider is the stain base type, water, oil or fortified.
The rumor is that water-based stains don’t penetrate the wood as well as oil-based. Some manufactures are using additives that help with this issue. They claim the additives will address cracking and peeling as well. I also read that water-based stains will often last longer than oil-based, although the prep work to refinish can be more involved. Unlike oil-based stain, all the old water-base stain will need to be removed before applying a new finish. Of course, a little more work may be worth the effort in order to use a non-toxic, easy to clean stain.
These stains are often a base of linseed, tung or soy oils. These naturally will penetrate deeply into the pores of the wood, but it is noted that not all oils perform the same. I read that linseed oil is a wonderful breeding ground for mold and spores. If you use linseed oil, look for a mold-resistant chemical additive. Applying an oil-based stain is easier than water-based in that it doesn’t require full stripping and sanding. Touch up can be done in just the high traffic areas that need it. It’s important to know that many oil-based stains have a high VOC content, are more difficult to clean up (rags used for clean up are a potential fire-hazard as we just witnessed with a good friend who is building a new home here in Olympia).
Epoxy-fortified water-based Stains
This is the latest in deck finishes. A small amount of epoxy is added to a water-base stain to create high wearability and color retention. This is formulated to have the deep sheen you’d expect in an old-style oil base finish. Added to the mix is a chemical to break surface tension to allow the stain to penetrate deeply into the wood. Refinishing with this stain is the same as with other water-base stains, it’ll require full scraping and sanding, but won’t have to been done as often. Manufacturers claim their products will last 3 to 5 years before needing to be refinished.
Here is a list of resources, it’s not complete but a good place to start:
Lastly, I have used a product called OS Hardwax for interior purposes with great success, it’s non-toxic (edible in fact) and produces a lovely finish. I have not used it for exterior purposes but have read some accounts of folks applying it to decks with satisfactory results. The product is environmentally benign and easy to apply and reapply. It may be worth a little extra research when considering what to use on your next deck project. I’ve purchased this product from Windfall Lumber, here in Olympia, they can answer any questions you may have about the product.
Thanks for reading!
Posted on November 17, 2009