You found that cute DIY project on Pinterest, and now the preparation begins. So, you head over to your local hardware store and check out their lumber wares. There are many different types of wood, so you may be wondering, “What’s the difference is between treated and untreated lumber?” Both have different uses, and getting the wrong kind may lead to the Pinterest-Fail of your home improvement nightmares. What do you do?
Untreated lumber goes from the forest to the lumberyard with a quick run through a sawmill. It is as close as you will get to “real” wood without chopping it down yourself. Treated wood is infused with chemicals; during the process, the wood is loaded into a tank and all of the oxygen is removed. Next, the chemicals are added to the tank under pressure which forces them into the wood.
The chemicals help the wood resist weather damage like warping from humidity and moisture, insects like termites and boring beetles and wood rot.
The chemicals used to treat wood have changed over the years, with some combinations no longer in use. But no matter what the combination, there is one thing that is consistent: Every chemical used to treat wood is hazardous to your health. You could be expose yourself to arsenic, PCP or creosote, all of which can be absorbed through your skin.
The USDA has banned many of these chemicals because they can harm people, animals, soil or groundwater. While they are still being used to treat wood, the wood itself is labeled for where it can be used: above ground, in the ground, a permanent wood foundation or in salt water. Labeling for where the wood can be used does not mean it has more of one chemical over another. It’s also no guarantee that the same chemicals were used in one treatment plant versus another.
Nowhere — nowhere! — in the labeling for how treated wood can be used is there a code for “use it to build a crib for your baby,” or “use it to build your dining room table.” While the usage codes imply that it could be used to build a treehouse for your son and his friends, or a she-shed for your daughter’s playhouse, knowing what you now know about the chemicals used to treat it, do you really want to?
So where is a good place to use treated wood? Using it to build a fence around your property is probably a good idea since the fence will be exposed to the elements and bugs 24/7/365. However, if you are a “Mr. Wilson” type with a tendency to chin wag with your neighbor a great deal, you might not want to rest your chin on it too often, and should probably just use it for the in-ground posts and not the entire fence.
Can you paint treated wood to make it safer? The jury is still out on that one. Some research has shown that oil-based semi-transparent wood stains might reduce exposure to arsenic; but, the stain would need to be repeated every six months to a year. Do you really want to do that with your DIY project?
When is it okay to use untreated lumber in your home? Guys who know their lumber will tell you “Never!” But first, they’ll look at you like you’ve stepped in front of the television in the middle of the SuperBowl.
If the USDA doesn’t think you should use it to make a cutting board because of the possibility for arsenic to leach into your meat, you probably shouldn’t even bring it into the house. So what are your options for that DIY cutting board in the shape of a cupcake?
Natural wood is the best option for any wood projects that will be in your home. If you want to build something that will be exposed to moisture or bugs and is at risk for rot — like a unique window planter for your kitchen herbs — there are some woods are naturally resistant. For example, redwood and red cedar can be both make a gorgeous cutting board.
Treating a wooden project when you want to prevent drying out or to protect it from little hands or paws. If you are making a cutting board, it should be oiled or seasoned to keep it sanitary and looking new. It will also help to extend the life of your cutting board and stop other liquids, like blood or bacteria, from getting into the wood fibers.
There are also options for using untreated wood outside. One is to use redwood or red cedar, and the other is to paint wood with an oil-based exterior paint. If you will be using natural wood for a fence post, you can paint the end that will be in the dirt with an enamel paint.
No matter what your project, inside the home or outside, always make sure you know whether the wood you are using has been treated.