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Can you paint treated wood

by Tomislav Najdovski on Jan 11, 2023

Can you paint treated wood

 

In this article we will try to answer yet another question that DIY enthusiasts all over the planet often wonder. Can you paint over treated wood? We are going to try to give you as straight an answer as possible by, as always, first explaining what treated wood is and what makes it different from non-treated wood, then exploring the question, of what you need if you were to paint over your treated wood surface by giving you a step by step guide to how it is actually done.

What is treated wood

Treated wood is, just as it implies, wood that has been treated in a special way in order to prolong its longevity of the wood. Normally you would use different types of preservative chemicals to protect the fibers of the wood from structural degradation, decay of fungi, termites, marine organisms, and fire.


When talking about treated wood you often hear that the wood has been “Pressure Treated” (PT), which means that the wood has gone thru a process where the preservative chemicals have been infused into the wood, thru high pressure, in order for the chemicals to go beyond the surface and actually penetrate deeper into the wood, creating a better protection that still is in place, should the surface of the material become damaged in some way.


PT also has the positive side effect that any excesses of the chemicals are removed since it is the actual fibers of the wood that gets infused leaving only enough chemical in the wood in order to protect it.


The difference between treated wood and non-treated wood is pretty simple; it lasts longer. In certain environments, untreated wood can actually begin to rot within 1-2 years, which is unheard of when it comes to treated wood. The same goes for structural damage on the wood caused by termites or other marine organisms. With treated wood, you reduce the risks of these types of damages significantly.



Can you paint over treated wood?


Yes, you most certainly can. But as always there are a few things that you have to keep in mind before starting to apply the paint of your choice to the wood you are working with. Pressure-treated wood is most often used when building outside since it improves the protection of the wood from wear and tear caused by weather and sun. So before painting your garden fence, built of pressure-treated wood, you should really leave it for one season before thinking of painting it. And more importantly, when it comes to pressure-treated wood, ensure that the moisture ratio is not above 16%.


It is a common misconception that pressure-treated wood is free from any type of maintenance since it has preservative chemicals already in the fiber of the wood. But that is not the case, the treatment simply prolongs the durability of the wood, and to keep that new fresh look of the material you need to apply something on the surface as well. And paint of course acts as a sealer and top coating as well and works really well if you prefer a color on the surface instead of seeing the raw wood.


Preparations, groundwork, and how to guide

In any type of paintwork, no matter what the material or what that material has been thru before, success lies in patience, precision, using the correct tools, and thorough groundwork and preparation. Always read the instructions on the label of the paint that you want to use and then simply follow this guide and you will get the surface shining in the color of your choice in no time at all.


Always start with wiping off the surface freeing it from any debris that might be stuck on top. If the surface has been painted before, you need to scrape it off and then wash the surface down with a powerful cleaning product, The Fiddes Wood Surface Cleaner is good to start with. Make sure to rinse it thoroughly with clean water and then let it dry. Once the surface is dry, you can move on to using sandpaper with a lighter grit, like Sanding Sheets from Starcke. If you are working on a larger surface, you might want to use a sanding machine. Doing manual sanding over larger surfaces can be really hard work.


Once done, and if you are working on the material used outside, like a wooden fence, you need to oil the endpoints of the material with an oil that is designed to further help the material withstand wear and tear from weather, such as rain, moist, snow, and sunlight. You will only need one coating of this oil and you should only use it where the endpoints are exposed. We recommend using Ronseal Shed And Fence Preserver


Next step is to use a primer. Primers should always be used when painting since it helps the paint stick better to the surface. You could really see it as a base coat used to help treat the surface before adding the top coat, which in this case is the paint of your choice. The primer is formulated to ensure maximum adhesion. Better paint adhesion makes sure that your paint job lasts longer. The primer also acts as a sealer to the surface, which means that the first few coatings of your paint will not be absorbed by the material. Thus less amount of paint is needed. Ronseal All Surface Primer And Undercoat is a good option to use.


If you have followed the steps above, and given the primer enough time to dry completely, it is time to apply the paint of your choice. Now there are a few different types of paint that can be used on treated wood, each type with different characteristics, pros, and cons. But for painting pressure-treated wood the best paint to use is an exterior latex paint of high quality. Exterior latex paint is water-based paint and that is exactly what pressure-treated wood needs. You really should avoid using oil-based paints on this particular material. Exterior latex paint comes in a wide variety of colors, sheens, and shades so you definitely do not run out of options. 


Apply the paint with a brush of your choice or a roller for the larger surfaces. Dip the brush, or roller, in the paint and apply evenly across the surface. Make sure not to use too much paint each time you dip the brush or roller, that might cause the paint to drip and you will have to sand down and redo the whole thing again to avoid weird patterns on the surface. depending on the paint you choose, two or three coats should be enough. Given the fact that a primer has been used, two coats might just be enough



Summary

Most often when you talk about treated wood you refer to the process of pressure treatment or PT, a process where preservative chemicals are infused in the wood using high pressure.

The difference between treated wood and non-treated wood is pretty simple; it lasts longer. In certain environments, untreated wood can actually begin to rot within 1-2 years, which is unheard of when it comes to treated wood. 


Treated wood is not as many people think, free from maintenance, and painting this type of wood is definitely something you can do. It is however important that the treated wood is completely dry, with a maximum 16% moisture ratio. If you are painting for example a garden fence, leave it out one season before applying the paint.


Preparations and groundwork are as always very important. Start with sanding the surface a bit with sandpaper before using a primer, to get the paint to adhere better. Since most treated wood is being used outside, oil the endpoints of the wood to help the material further withstand wear and tear from weather.


Once the primer is dry, apply the paint of your choice using either a brush or roller.