Why Chicago Contractors Are Switching to Engineered Lumber

Engineered Lumber Is Everywhere Now

Walk onto a new construction site in Chicago today and you'll see something that would have puzzled a framing crew 25 years ago: floor joists that look like small I-beams, headers made from layered veneer rather than solid wood, and rim boards that are perfectly straight and uniform. Engineered lumber products have gone from niche specialty items to mainstream construction staples, and Chicago's building community has embraced them for compelling reasons.

What Is Engineered Lumber?

Engineered lumber is manufactured by bonding wood veneers, strands, or fibers with adhesives under heat and pressure. The result is a product that's stronger and more dimensionally stable than the trees it came from. The main products are:

• LVL (Laminated Veneer Lumber): Thin veneers of wood glued in layers with the grain running parallel. Used for beams, headers, and ridge boards. LVL beams can span much farther than solid-sawn lumber of the same depth.
• I-Joists: An engineered product with LVL or solid-sawn flanges (top and bottom) connected by an OSB web (the middle). They're lightweight, don't shrink, twist, or crown, and come in lengths up to 60 feet. They've largely replaced 2x10 and 2x12 solid-sawn joists in new floor systems.
• LSL (Laminated Strand Lumber): Made from oriented wood strands bonded with resin. Used for studs, headers, and rim boards. LSL is remarkably straight and consistent.
• PSL (Parallel Strand Lumber): Long strands of wood bonded under high pressure. Extremely strong, used for columns and beams where heavy loads and long spans are needed. The brand name Parallam is the most recognized.

Why Contractors Love It

Consistency: This is the number-one reason. Every LVL beam of a given size has the same published strength value. There's no guessing, no rejecting twisted or bowed pieces, no weak knots in critical locations. When a framing crew installs an LVL header, they know exactly what it can support. This predictability speeds up framing and eliminates structural uncertainty.

Longer spans: Open floor plans are the norm in modern design, and open plans require longer clear spans. A 2x12 solid-sawn Douglas fir joist maxes out at about 18 feet for residential floor loads. An engineered I-joist of the same depth can span 24 feet or more, depending on the product. This eliminates the need for intermediate bearing walls or beams, giving architects and homeowners more design flexibility.

Dimensional stability: Solid-sawn lumber shrinks as it dries. In a floor system, this shrinkage causes nail pops in drywall, squeaky floors, and uneven surfaces. Engineered lumber is manufactured at controlled moisture content and barely shrinks after installation. Drywall contractors love working in buildings framed with I-joists because their ceilings and walls stay flat.

Material efficiency: Engineered lumber uses smaller, faster-growing trees more efficiently than solid-sawn lumber. Veneers and strands from trees too small for sawlog production become structural products that outperform old-growth timber. As the quality and size of available timber continues to decline, engineered products bridge the gap.

Considerations and Limitations

Engineered lumber isn't a universal replacement. It costs more per piece than solid-sawn lumber — an I-joist typically costs 20-40% more than the 2x equivalent. It also requires specific installation details: I-joists must have web stiffeners at bearing points, LVL beams cannot be notched without engineering approval, and all engineered products must be protected from moisture during construction.

Fire performance is another consideration. I-joists with thin OSB webs lose structural capacity faster in a fire than solid-sawn joists. Building codes and fire departments are well aware of this, and specific fire protection details apply to engineered wood framing.

What This Means for Your Project

If you're building new or doing a major renovation in Chicago, your contractor may specify engineered lumber for parts of the structure. This is a good thing — it generally means flatter floors, straighter walls, and fewer callbacks. We stock LVL beams, I-joists, and LSL products in standard sizes and can order specialty dimensions. Talk to us during the planning phase so your materials are ready when framing starts.