Why The Yellow Tag on Lumber Matters More Than You Think

Always check the end tag

When you’re standing in the lumber aisle, comparing two 2x4s that look almost identical, it’s easy to reach for the cheaper option. After all, wood is wood—right? Not quite. That small yellow tag on the end of your lumber actually carries big information about how the wood has been treated, and choosing the wrong one can lead to costly problems down the road.

Above Ground vs. Ground Contact: What’s the Difference?

Treated lumber comes in different levels of preservative retention, depending on how it’s meant to be used.

• Above Ground Treated Lumber is designed for projects where the wood will remain well above the soil and is easy to repair or replace if needed. It has a lighter level of treatment.

• Ground Contact Treated Lumber has a higher preservative retention level, making it much more resistant to rot and decay. It’s specifically designed for situations where the wood touches the ground or is within 6” of soil after landscaping.

If above ground lumber is mistakenly used in ground contact situations, it will rot over time—potentially weakening your deck, dock, or outdoor structure.

Why This Matters for Your Projects

The American Wood Protection Association (AWPA) Standards are very clear: Ground Contact treated wood must be used when:

• Wood is less than 6” above the ground after grading and landscaping.

• The wood is difficult to maintain, repair, or replace.

• The component is critical to the safety and performance of the structure (such as joists, beams, and supports).

This change affects most deck joists and beams, as well as structures like freshwater docks and floating docks. In harsher environments—like marine or coastal settings—even stronger treatments may be required.

Reading the Tag Saves Headaches Later

Not every lumber tag looks exactly the same, but they all provide key details on how the wood is treated. That little yellow tag helps you quickly identify whether a board is rated for Above Ground or Ground Contact use. By paying attention to it, you can avoid future repairs, replacements, and frustrations.

The Takeaway

When you’re shopping for lumber, don’t just look at price or appearance. Take a moment to check the yellow tag. Choosing the correct treated wood for your project is about more than saving a few dollars today—it’s about ensuring your deck, dock, or outdoor structure is safe, durable, and built to last.

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About Outback Deck, Inc.

Outback Deck, Inc. brings inspiration to outdoor living spaces. We believe if you have an outdoor space, you should WANT to spend time in it.  Our commitment to providing the best customer experience and creating outstanding value in your new deck or porch is unmatched in the industry.  For more information, please visit www.outbackdeck.net  life happens out back