Pressure-treated lumber is vital for various uses, especially outdoors, due to its improved durability. And like most outdoor projects, you’d expect an impressive finish which includes painting or staining. As a woodworker, you already know how vital sanding a piece of wood before finishing is, but some confusion may arise regarding pressure-treated lumber.
If you’re using treated timber for your project, you may wonder if you can sand it before finishing to get a smooth surface. You’re not alone in this, as many others have posed the same question, and rightly so, considering the chemicals infused into it. This is why we will help you to answer the question: can you sand pressure-treated lumber?
Yes, you can sand pressure-treated lumber to get a better appearance. However, specific measures must be taken to prevent the release of toxins into the atmosphere or damage the wood surface.
There’s much more to sanding treated wood than a simple yes or no answer, so you must follow this piece to learn everything about the process. In this guide, we’ll go deeper into the most suitable type of pressure-treated timber to sand, how to do it to protect yourself, and more.
What is Pressure Treated Wood?
Pressure-treated wood is a type of lumber treated with preservative chemicals under high pressure. The aim is to improve the wood’s quality, increasing its lifespan and making it suitable for various uses.
Infusing just the right amount of preservative chemicals into the lumber makes them resistant to insect attacks and natural elements like moisture and humidity. Generally, treated wood has five times more durability than standard wood, adding decades to your lumber. There are two types of pressure-treated timber: above-ground and below-ground wood. Also, the additional two grades are beneficial as they vary based on appearance.
Can You Safely Sand Pressure Treated Wood?
Sanding uses sandpaper or a mechanical sander to scrub wooden surfaces for the desired finish. This process is usually done in preparation for finishing with its ability to hide imperfections like scratches.
While sanding pressure-treated wood is unnecessary as the surface is already smooth, you can still sand when required. However, before you run away with it, sanding wood that has been pressure-treated requires certain factors to be in place. Sanding can further improve the surface and make it adhere to paint and other finishes.
There needs to be more clarity about whether you should sand pressure-treated wood, with several popular publications pitching their tents on either side of the divide. While the experts have given their verdict, you should also be able to decide. So, we’ve included a pros and cons section to make it easier.
Pros and Cons of Sanding Pressure Treated Wood
How about checking out this benefits and drawback section to better understand which option to choose? At the end of this part, you should have a clearer idea if you should go ahead with the sanding or hold back.
Pros
- Prevent Splinters: Sanding with the correct grit can get a smoother surface than obtainable. Smooth surfaces prevent splintering, which can make the wood unsightly.
- Better Appearance: Sanding can improve the appearance of the wood by leveling the surface, eliminating tough patches, and generally giving a polished look.
- Improve Adhesion: If you want better adhesion when you paint or stain pressure-treated wood, you should seriously consider sanding. Most treated lumbers feature highly smooth surfaces that make it challenging for the finish to stick to the wood.
Cons
- Exposure to Toxins: Pressure-treated wood is infused with several chemicals to improve its durability, and sanding can release these toxins into the environment. Wear protective gear such as nose masks and goggles to prevent inhaling dangerous particles.
- Risk of Damaging The Wood: You can easily over-sand the wood, weakening its core and damaging its surface. It defeats the purpose of a more durable alternative to standard wood.
- Irreversible: You cannot reverse the effects once you’ve sanded through the chemical coating. Combined with the unpredictable results you can get as the chemicals soak inconsistently underneath the surface, it’s impossible to regain the original surface. Unlike standard wood, where sanding deeper may reverse the procedure.
You can make your decision easier by considering the type of project and if sanding is necessary. Sanding for projects that require improved aesthetics is understandable; however, you can do without sanding pressure-treated lumber for fences and utility sheds.
Consider using standard wood that has yet to be treated for the project. Quality traditional wood like cedar may suit the task if sanding is necessary. Another factor to consider is the type of pressure treatment. CCA-treated timber is highly toxic and should be avoided if sanding is involved; instead, stick to the safer water-based ACQ alternative.
How to Sand Pressure-Treated Wood?
If you’ve decided to sand your pressure-treated lumber, understanding the best way to safely sand the wood is essential. Whether you’re a professional woodworker or a DIY enthusiast, you’ll need a few adjustments to your knowledge of sanding standard lumber. Before we go into the straightforward process, let’s consider the materials needed.
1. Materials Needed
Getting the correct materials is the first step to safely sanding your pressure-treated wood. This will significantly increase your chances of getting a clean finish without exposing yourself to toxins.
- Suitable Sandpaper Grit: Extremely rough grits should be avoided except where significant imperfections are present. Instead, stick to medium roughness between 100-150 grit for the first sanding phase. Afterward, you can use grit between 180-200 to prepare for staining or painting. For extra smoothness, grits of over 320 are the way to go.
- Protective Gear: If you intend to come out of this project unscratched, you must get your protective gear. Get an overall to protect your skin, gloves, hat, goggles, and a nose mask before sanding. For extensive projects, you may need a respirator.
- Sander Type: You can use various available sanding materials with variable importance. Sandpaper is the tool for hand sanding surfaces, while sanding belts produce faster results. A sanding block is suitable for flat surfaces, while a flexible sanding sponge will work wonders on contour areas. Power sanders with dust-collecting systems are the most suited for this project.
2. Steps
Follow these easy steps to safely sand your pressure-treated lumber in under a few minutes, depending on the size of your project.
- Wear Protective Gear: Ensure you wear your protective equipment, including your overalls, goggles, gloves, and respirator, before proceeding.
- Choose a Suitable Location: Set the wood in a well-ventilated environment that’ll not trap the released gases for long.
- Sand with Coarse Grit: Always start sanding with coarse grit sanders as it fixes imperfections and allows you to ease into the finer grits. Sand along the grains for improved results.
- Move to Finer Grits: After sanding with a coarse grit sander, you can move to the suitable fine grit. The best size to use for your needs, with staining and painting, is 180-200 grit, while you’ll need above 320 to get an extremely smooth surface.
- Clean the Wood: The wood surface will be covered with dust particles after sanding, so it is necessary to clean the timber. Brush off the dust and wipe with a damp cloth or tack.
FAQ’s
Safely sanding pressure-treated wood requires carefulness, so feel free to go through this frequently asked questions section for further clarity.
Ans: You should sand pressure-treated timber that requires painting or staining, as it improves its adhesion capacity and ensures the finish lasts longer.
Ans: The benefits you can get from sanding treated wood include fixing imperfections, opening the wood pores to enable the finish to penetrate deeply, and creating an aesthetically pleasing appearance.
Ans: Potential exposure to harmful chemicals injected into the wood and coated around it can cause severe damage to the skin, respiratory and neurological systems.
Ans: The best option is to leave the wood unfinished; they typically have impressive surfaces. You can also consider using a chemical stripper to strip the surface coat.
Conclusion
Safely sanding pressure-treated wood is possible with the proper guidance. However, you must understand the potential drawbacks before proceeding, including the possible exposure to toxins and the unpredictability of the sanding result. Nevertheless, if you get the correct materials and follow best practices, you can complete the sanding in minutes.