When the exterior of your home is ready for an upgrade, there are many projects you could take on.
Siding, fencing, and deck building are all wood-based projects that can add value and curb appeal to your home.
If you’re carrying out this type of wood-based work, it’s highly likely you’ll be using pressure treated lumber.
Pressure treated wood is often the best choice for longevity and durability and is perfect for exterior projects. And when you use the best stain for pressure treated wood, your project will be protected from the elements.
Pressure treated wood has been treated with chemicals that both preserves the wood and protects it from rot and insects. When treating the wood, it is placed in a depressurized holding tank. During this process, all the air is removed from the tank and replaced with preservatives.
Though this chemical bath is excellent for protecting wood against insects and rot, the process will not protect the wood from damage due to corrosion, sun exposure, and other problems resulting from a life spent exposed to the elements.
Pressure Treated Wood
Green wood and green treated lumber are two phrases that refer to pressure treated lumber. When the lumber is newly treated, it takes on a green hue for which it’s named.
There are different types of green treated lumber, as explained below.
- Kiln-Dried: Lumber that’s been kiln dried is generally ready to stain right away. It’s no longer wet after a long stint in the kiln. This can be a real time saver for homeowners in a hurry. When searching for kiln-dried wood, look for markings on the wood that say ADAT or KDAT. These stamps signify that the wood has been properly treated and then air-dried or kiln-dried
- Wet Treated Wood: When the wood is fresh from being pressure treated, it’s still wet and will remain damp for some time. Wood in this state from the pressure treating process will be considerably heavier than other options at your disposal. This wood will also need to dry out for at least 3-6 months before you can stain it, so factor that into the equation
- Treated Wood with Water Repellent: If you find pressure treated wood that’s been “Thompsonized,” this wood has been treated to be fully water repellent in addition to the pressure treatment. A quick way to tell is to sprinkle a few drops of water on the wood. If it beads water, it has probably been treated with a water repellent.
Process of Pressure Treating Wood
When wood is put through the pressure treatment process, preservatives and chemicals are forced into the wood. These chemicals and other materials work to ensure the finished product can withstand the elements even in harsher climates.
For many years, the most common chemical used in pressure treating wood was chromated copper arsenic, or CCA. This chemical was very toxic and harmful and thankfully is rarely if ever used anymore. Today, the most common chemical used is alkaline copper quat, or ACQ. ACQ is much better for the environment. The only exception is that the copper in ACQ is very harmful to marine life so if your deck is located near a river or lake, consider using wood that is not pressure treated.
When to Stain Pressure Treated Wood
As discussed above, some pressure treated woods are technically still wet. As such, they can’t be sealed until they’ve had a chance to dry.
Be careful though– the longer this green wood is left exposed to the elements, the more likely it is that the UV rays from the sun will spoil the wood or water will work its way in and begin to cause damage.
When you think the wood looks dry, be sure to test the dryness before staining. Luckily, there is a simple trick. All you need to do is sprinkle a little water on the wood’s surface. If the water forms beads on the surface, the wood is still wet and not ready to be stained. Conversely, the wood is dry and ready for stain if the water soaks in. Typically 3-6 months is enough time for pressure treated lumber to dry out.
If you’re using wood that’s been kiln-dried or air-dried, this wood is ready to stain as soon as your fence or deck is built.
Best Exterior Wood Stain
There are two different categories of wood stains: water-based and oil-based. Both work well for different applications. The best exterior wood stain depends on the project at hand.
When using a water-based stain, you don’t have to wait long to get the job done. Even when the wood is slightly damp, it can absorb the water-based stain. If you make a mess, cleaning up a water-based stain is a simple task with no need for solvents. Just use soap and water to clean up.
Oil-based stains are notoriously messy and have a stronger odor. Also, there can be no moisture in the wood when you are ready to apply the stain. This means you need to allow the wood to be completely dry with no rain in the forecast before staining. Oil based stains are typically easier to apply than water based stains, but they also take longer to dry, which is why they don’t show lap marks as easily.
The downside is they don’t last as long either. If you’re looking for a quick stain job that will look nice for about a year or less, and you don’t mind restaining every year, there are a few oil based stains will work. The other big issue with many oil based stains is mold growth. The natural oils in the stain can be a food source for mold, mildew and algae. If you see large areas of a deck that have turned dark, it’s frequently caused by mold feeding off the deck stain. If your deck, fence or siding is on the north side of your house, you may notice more mold and mildew growth, since this side of the house usually gets more shade. Also, be careful using oil based stains if you live in a wet climate, or have lots of trees nearby. These can both cause accelerated mold and mildew growth. In all of these cases, oil based stains may make the problem worse.
In general, when it comes to the best stain for pressure treated wood, water-based stains generally make the better option.
Best Stain for Pressure Treated Wood
Take a quick glimpse now at 3 of the best exterior wood stains.
DEFY Extreme Wood Stain (semi-transparent)
A great stain from DEFY, this water-based stain provides your wood project with all the protection it needs from those fierce UV rays. Also, this stain is waterproof so that your fence or deck stays safe from water damage.
This stain penetrates the wood effectively and with a beautiful semi-transparent color, allowing the natural beauty of the wood to shine through.
- Easy to apply
- Exceptional penetration
- Remarkably durable
- Dries extremely fast – make sure you don’t apply in direct sunlight!
- Prep process is more involved – wood has to be cleaned and brightened first
#1 Deck Solid Color Wood Deck Stain – (solid/opaque)
#1 Deck Stain is a water-based stain that’s available both in both a semi-transparent version and a solid color version. If you’re looking for great performance that doesn’t come at a premium price, #1 Deck is it. The semi-transparent version is priced in the mid-$30s per gallon. The solid stain is priced higher, but it gives you much more UV protection and will last years longer than the semi-transparent. A recent trend is to stain the railings and posts with a solid stain, and the horizontal deck boards with a semi-transparent.
Your wood will also be highly resistant to damage from the sun’s rays. Its resistance to the elements makes it one of the best stains for pressure treated wood for its price.
- Resistant to mildew
- Simple application
- Prep & stain the same day
- Comes in a jug – you’ll need to pour off into a roller pan or paint can for trimming
TWP Stain (semi-transparent)
If you insist on using an oil-based deck stain, and don’t mind the given limitations, give TWP a try.
This semi-transparent is fairly easy to apply and will penetrate the wood to protect from UV rays. Be cautious when using this in shady areas or if you’re surrounded by lots of trees as mold and mildew could become a problem. Although this is one of the better oil-based wood stains, keep in mind that annual maintenance coats may be necessary.
- Easy to apply
- Penetrating formula resists peeling
- Doesn’t show lap marks
- Requires more frequent maintenance coats
- Oil based formula requires clean up with messy solvents
- Longer dry time
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