When is using untreated lumber better?

The obvious advantage of using untreated lumber is that there are no health risks involved. It's as close to wood in it­s natural form as you're going to get without grabbing an axe and chopping down your own tree. If you're building anything that people will regularly be coming in contact with -- such as playground equipment, lawn furniture or benches -- you should always use untreated wood [source: Houlihan and Wiles].

Untreated lumber should also be used when you're dealing with gardening, whether you're building a raised garden bed, a flowerpot, or just making mulch. Some of the chemicals used to treat wood are meant to kill insects, which means they probably won't do wonders for your soil either. They can damage your flowers and make their way into your vegetable gardens -- ruining your prized tomatoes.

An obvious advantage of untreated lumber is its price; it's much cheaper than treated lumber. Since CCA-treated lumber was taken off the market, new treatment techniques use high levels of copper, which is more expensive. As a result, the cost of treated wood has risen considerably [source: Morrison].

When working with untreated wood, you don't have to worry about protecting your skin. You may want to wear a mask to keep from breathing in sawdust, but you can work in short sleeves and/or shorts without any fear of endangering yourself. The same can't be said for treated wood. In fact, when working with treated lumber, you should be adequately covered -- long sleeves, long pants and eye goggles are all a good idea. Afterward, make sure to clean any sawdust from you or your clothing thoroughly. And, of course, you want to avoid breathing in any sawdust particles from treated lumber [source: McClintock]. At a minimum, you should wear a dust mask/facemask while working with treated lumber. And, if you have one, a respirator would be even better.

At the end of the day, the ease of mind that comes with using untreated lumber may be worth it. You don't need to worry about potential health concerns, even if the wood comes in contact with your soil or water supply.

Although there are health hazards to consider, treated wood does have its advantages. Treated wood was designed to defy the effects of ­natural aging. As wood is exposed to the natural elements, it slowly breaks down. Moisture is especially hard on wood. If treated, wood can last much longer than normal, but to make sure your treated lumber lasts as long as possible you need to match its treatment level with the right use. Lumber that is touching the ground, for instance, requires a higher treatment level than lumber that is not [source: Viance].

Treated lumber does have other advantages. Many types of treated wood are resistant to insects, like termites, that cause huge amounts of damage and cost home owners large sums of money. The chemicals used in the treatment process are toxic to insects, so any bug that tries to eat its way through a treated support beam will expire. On top of repelling bugs, treated lumber can also be fire retardant, taking longer to catch on fire and burning much more slowly when it does [source: WiseGeek].

In instances where treated lumber doesn't touch the ground and isn't exposed, it is relatively safe. You can also use certain oil finishes to protect treated wood and reduce the risk of it leaching dangerous chemicals during contact [source: Natural Handyman].

While treated wood has distinct advantages, you might decide that they aren't worth the added health risk. Yet, if you need something to last a long time and you know people won't come into much contact with it, treated lumber might be the better choice. In general, though, treated lumber shouldn't be used where untreated lumber will suffice.

The next time you're working on a project using wood, consider the advantages and disadvantages of both treated and untreated lumber before making a purchase.

For more information, check out the links on the next page.

­