Structural LVL vs. Standard Lumber: Why Your Deck Joists Matter
If you've ever looked across an older deck and seen the boards rolling like a gentle ocean swell, you've seen a framing problem. The boards get blamed, but they're usually just following the joists underneath.
That's the problem engineered framing is meant to solve, and it's why we offer a Structural LVL Frame option.
What is LVL?
LVL stands for laminated veneer lumber. Instead of sawing a joist out of a single log, thin layers of wood veneer are bonded together into a solid beam. The result is an engineered product that's much more uniform than sawn lumber.
The LVL we use for deck framing is pressure-treated, so it's made to handle outdoor exposure.
Why does standard lumber move?
Sawn lumber comes from a tree, and trees aren't uniform. Knots, grain direction, and moisture content vary board to board. As the wood dries in Colorado's climate, those differences show up as crowning, twisting, and cupping. Our dry air and wet spring snow make that cycle more aggressive than in a lot of places.
A good builder sorts lumber and crowns joists consistently, which helps a lot. But you're still working with a natural material that keeps moving.
What does LVL do better?
Straighter joists. Because it's engineered, LVL starts straight and stays more consistent, so the deck surface stays flatter.
Predictable strength. Engineered lumber has consistent, published properties, which makes the design more predictable.
Better under premium decking. Composite and PVC boards show every high and low spot in the frame. A flatter frame makes expensive boards look like they should.
When does LVL make sense?
LVL is a strong middle ground between standard lumber and steel framing. It's a good fit when:
You're putting composite or PVC decking on top and want a flat, clean surface
You want a better frame but prefer to stay with wood
The deck is large enough that small variations would show
If your home is in a wildfire area or the deck is very tall, steel may be the better call. Standard lumber is still a fine choice for a smaller, simple deck. Each option has its place.
How do I decide?
Start with how long you plan to own the house, how high the deck is, and what's going on top. Then compare the frames side by side. We walk through all three, standard lumber, LVL, and steel, at every design consultation, and your quote breaks out the framing so you can see the difference.
