Finding the best deck stain will depend on what wood your deck is made of, and what you want it to look like. First of all, we should distinguish between stains and sealers.
SEALERS. A sealer is applied to keep water from penetrating the wood. If you buy a sealer with UV inhibitors, the effects of the sunlight will be diminished. It will take much longer for the wood to fade or discolor. Since the goal here is normally to preserve the original look of the wood, sealers are typically clear.
I’m not a big fan of sealers because they have a wax base which forms a solid coating over the surface of the wood. Water beads on it and stays there for many hours (even days) after a rain. This creates a slipping hazard, and the solid coating is not the best thing for the wood.
The wax wears off and you have to apply it again every year. This is not my favorite job, but you have to do something. Leaving the wood to fight the elements without any protection will cause it to degrade quickly, shortening the life of your deck substantially.
STAINS. As the name implies, stains will change the color of the wood. The best deck stain is one with a penetrating oil base. My father always used linseed oil on his exterior wood surfaces. It was semi-transparent and darkened the wood slightly. It also smelled up the neighborhood for nearly 2 weeks.
Although linseed oil is still one of the best things to consider if you’re focusing on the benefit to the wood, there are several products available today that are of equivalent value. The more wood penetration by the stain, the more protection is given to the wood.
If the wood is already weathered, a solid/opaque stain will do the best job of covering imperfections. Once it’s on, it’s a lot of work and expense to go back to a semi-transparent stain in the future. So figure you’re stuck with opaque for the long term.
The more opaque a stain is, the quicker it will show wearing and weathering. Even the best deck stain, if opaque, might need re-application every year, while a semi-transparent, wood tone treatment will last much longer. Solid opaque stains do not show the grain of the wood. Others do.
An interesting design option is to use semi-transparent on the deck, and opaque on the railings and/or siding, where the sun’s effects aren’t so strong. This two-color option could really be beautiful.
Keep in mind that darker colors absorb more heat than light colors. This could mean that the deck becomes uncomfortable for people with bare feet. It’s probably a good idea to choose a color that blends with the siding on the house, or one that contrasts.
The stains we haven’t talked about yet are water-based stains. These usually come in solid colors. They protect the wood, but you can’t tell that it’s wood. That might be your preference.
In conclusion, the best deck stain will be different stains for different people. Let’s recap to see which stain is best for you.
SEALERS – Coat the wood; don’t penetrate it. Those with UV inhibitors are best. Must be re-applied every year.
OIL BASED STAINS – Non-opaque stains will let the natural wood show through. They penetrate and protect the wood. They provide a richer look. They will need re-application every 2 to 4 years depending on weather conditions.
WATER BASED STAINS – These come in solid colors. They are better for the environment. They dry faster and are easier to clean. They are the most durable, lasting 7 to 8 years. They hide the natural wood look.
Have you picked your best deck stain? Good. Now I have a few tips regarding application.
APPLYING STAIN. Don’t use a power washer to clean the deck. It will strip the wood of any surface protection, and if you’re not VERY good at handling one, there’s a good opportunity to cause damage. Just use a watered down detergent with a mop.
Once you’ve prepared your deck, test the stain in an inconspicuous spot. This will confirm that you’ll be getting what you want. Apply the stain to higher surfaces first. This will eliminate the risk of dripping on areas already finished, which will leave spots. Avoid lap-over marks. Apply the stain to two or three boards at a time, and don’t stop in the middle of a board. If you allow stain to sit in a puddle, you will see the difference later. The stain has to be applied evenly across the entire deck surface.
Apply your best deck stain with a brush. It provides better penetration than either a roller or a spray. When covering a large area, stir the stain often so that the coloring doesn’t settle, making the stain at the top of the can a slightly lighter shade than what you’ve already applied. Apply at cooler times of the day so that the direct sunlight doesn’t cause fast drying. This will give the stain ample time to penetrate the wood.