- Deck framing needs pressure-treated lumber. It resists rot, insects, and ground moisture.
- Deck boards need to look good and hold up to foot traffic, sun, and Georgia rain.
- Pressure treated is right for the structure. It is not always right for the surface.
- Composite and pressure-treated decking boards are the two main surface options. They behave very differently over time.
Most homeowners assume deck lumber is deck lumber. But there is a reason the pros never use the same board on top as they do underneath.
The material holding your deck together and the material you walk on have different jobs. They face different conditions. They fail in different ways. Using the wrong one in the wrong place costs time, money, or both.
Why Does the Material Choice Matter This Much?
Because they wear out differently. Replacing the wrong one is expensive.
Framing lumber lives underneath the deck. It holds the load. It sits close to the ground, stays partially shaded, and takes on moisture from below. If it rots, you are not just replacing a board. You are tearing the deck apart to fix it.
Deck boards sit on top. They get direct sun, rain, and foot traffic. In Georgia, they also get a lot of humidity. If a surface board warps or splits, it looks bad and can become a safety issue. But replacing a few surface boards is a manageable repair. Replacing rotted framing is not.
Getting the material wrong does not cause equal problems in both places. That is why you treat them differently.
What Should You Use for Deck Framing?
Pressure-treated lumber is the standard. It is the right tool for the job.
Pressure-treated lumber is wood infused with preservatives. Those preservatives resist moisture, rot, and insects. That makes it suitable for use near the ground, where untreated lumber breaks down quickly.
In Metro Atlanta, heat, humidity, and seasonal rain speed up wood decay. Untreated framing lumber does not last in that environment. Pressure-treated does.
You also need the correct treatment level for where the lumber is going. Treated lumber is sold by use category, and the rating is printed on the end tag stapled to each piece. Above-ground stock is the lighter of the two common options. Ground contact stock carries more preservative and is built for constant moisture.
Height off the ground is not the only thing that decides which one you need. Industry treating standards call for ground contact stock on joists and beams that are hard to reach, hard to replace, and critical to holding the deck up. The same goes for framing where leaves, soil, or debris are likely to pile up underneath. A lot of deck framing fits that description even when it never touches dirt. Posts set in the ground or in concrete always need ground contact stock.
Your local building department has the final say, and inspectors read this differently from county to county. If you are not sure which rating your build calls for, sort it out before you order. It is a cheap decision to get right and an expensive one to fix. Our lumber and panels page covers the structural products we stock.
Best for: Joists, beams, posts, ledger boards, and any structural part of a deck frame.
What Should You Use for Deck Boards?
Two main options: pressure-treated decking boards or composite decking. Each makes sense in different situations.
Pressure Treated Decking Boards
Pressure-treated boards can be used on the surface of a deck, not just in the frame. They cost less upfront and are familiar to most builders.
The trade-off is maintenance. They will gray over time. They can develop small surface cracks as the wood dries out. They need periodic sealing or staining to hold their color. In Georgia, boards absorb moisture and dry out repeatedly through the seasons. That cycle causes movement and cracking. It is normal for the material, but worth knowing before you choose it.
Best for: Budget-conscious builds, painted or stained decks, and projects where upfront cost is the main driver.
Composite Decking
Composite is made from a mix of wood fiber and plastic, usually with a protective cap on the outside surface. It resists rot and insect damage, will not splinter the way aging wood does, and never needs staining or sealing. Capped boards hold their color better than pressure-treated wood.
It is low maintenance, not no maintenance. Plan on washing it once or twice a year so mold and mildew do not build up, especially on shaded sections of the deck.ss upkeep over its life.
Brands like Trex, TimberTech, and Fiberon offer composite in a range of colors and profiles. Some work with hidden fastener systems that keep the surface looking clean. The upfront cost is higher. That is the honest trade-off. But when you add up staining, sealing, and board replacement over ten or fifteen years, composite often makes financial sense. It also tends to stay cooler underfoot than stained wood on a south-facing deck in July.
Trex publishes detailed guidance on their decking lines and warranty coverage if you want to dig into the specifics of how composite holds up over time.
Best for: Low-maintenance decks, high-use areas, and any project where long-term appearance matters.
Can You Use Composite for Framing?
No. Composite decking is a surface product. It is not rated for structural use and will not carry load the way pressure-treated lumber does. The framing always needs to be pressure treated. The surface is where you have options.
Pressure Treated Decking vs. Composite Decking
| Pressure Treated | Composite | |
|---|---|---|
| Upfront cost | Lower | Higher |
| Maintenance | Periodic sealing or staining | Minimal |
| Appearance over time | Grays, may crack | Holds color well |
| Splinters | Possible as it ages | Unlikely |
| Suitable for framing | Yes | No |
| Georgia climate performance | Good with maintenance | Very good |
| Typical surface lifespan | 10–15 years with care | 25+ years for many products |
What Gets People in Trouble
A few patterns come up regularly.
Using framing-grade lumber as deck boards. Framing lumber is rougher and more prone to cracking than boards made for decking. It works in the structure. It is a poor choice on top.
Assuming all pressure-treated lumber is the same. Treatment level matters. So does the difference between structural stock and decking stock. Bring your list in, and we can confirm you are ordering the right product for each part of the job.
Skipping the hidden fastener conversation. If you are using composite, you may want a hidden fastener system for a cleaner look. That decision needs to happen before the first row goes down, not after. Trex’s Hideaway fastener system is one option worth looking at if you want a screw-free surface.
How Cofer Brothers Can Help
We stock both pressure-treated lumber and composite decking materials for Metro Atlanta jobs and projects. Whether you are a contractor pricing a full deck build in Norcross or a homeowner replacing surface boards in Dunwoody, we can help you get the right product in the right place.
Bring your material list or give us a call. We will look at it with you, flag anything worth a second look, and get you priced out.
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Frequently Asked Questions
Can I use regular framing lumber for deck boards?
Not recommended. Standard framing lumber is not pressure treated and breaks down quickly in weather. Even pressure-treated framing lumber is rougher than decking stock and more likely to crack. Use the right product for the right place.
Do I need pressure treated lumber for all deck framing?
In most cases, yes. Any framing member close to the ground, touching concrete, or exposed to moisture should be pressure treated. Check local building code for your specific situation. Also confirm the correct treatment level for ground contact versus above-ground use.
Is composite decking worth the extra cost?
For most homeowners who plan to keep the deck long-term, yes. No staining, no sealing, and most composite products hold up well in Georgia’s climate. Over ten or more years, the math usually works in composite’s favor.
Can composite decking be used for anything structural?
No. Composite is a surface material and is not rated for structural use. Joists, beams, and posts need to be pressure-treated lumber.
What is the difference between ground-contact and above-ground pressure-treated lumber?
Ground-contact lumber has a higher preservative level. It is required when wood is in or near soil, or touching concrete. Above-ground rated lumber is for framing that stays elevated and dry. Using above-ground stock in a ground-contact spot shortens its lifespan significantly. Confirm the rating before you order.
