Choosing the Right Floor System

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Choosing the Right Floor System:

2x10s vs. I-Joists vs. Floor Trusses

When planning a new home or cottage, the floor system you choose plays a major role in overall performance, comfort, and long-term durability. Today’s builders typically consider three main options: traditional 2x10 dimensional lumber, engineered I-joists, and open-web floor trusses. While each has its place, the differences in structure, strength, and versatility can dramatically impact how your home feels and functions.

Here’s a deeper look at how these systems compare—and why floor trusses are becoming the preferred choice for modern construction.

2x10 Dimensional Lumber: The Traditional Approach

For decades, 2x10 lumber has been a go-to option for floor framing. It’s simple, widely available, and familiar to most builders. However, as homes have evolved to feature more open layouts and longer clear spans, the limitations of dimensional lumber have become more apparent.

2x10s can be prone to shrinking, twisting, and warping over time, which can lead to squeaky floors or uneven surfaces. The time it takes to find the competent 2x10s and check the crowns on each one adds to the overall timeline of the build. Their structural capacity also limits how far they can span without support, often requiring more beams, posts, or walls. For homes requiring wide-open spaces or complex mechanical runs, this traditional option may not offer the flexibility homeowners expect.

Source: k.engel.construction

Source: Turkstra

I-Joists: Engineered Strength with Some Limitations

Engineered I-joists offer a step up from standard lumber. Made from flanges of solid wood or LVL bonded to an OSB web, they provide consistent performance and can span greater distances than dimensional lumber. Their uniformity helps reduce floor movement and improve sound performance.

However, I-joists still come with limitations. The OSB web restricts the size and placement of openings for electrical, plumbing, and HVAC systems. While small holes can be strategically placed, larger mechanical runs often require careful planning—or costly workarounds. In homes with advanced mechanical systems or custom layouts, this can add friction to the build process.

Floor Trusses: Superior Strength, Flexibility, and Efficiency

Floor trusses stand apart thanks to their open-web design and engineering precision. Built off-site in controlled environments, they’re designed to meet exact spans, loads, and layout needs. This factory-engineered consistency creates a stable, predictable floor system that resists shrinkage, twisting, and movement.

But the biggest advantage? Unmatched flexibility.

The open-web structure allows mechanical systems—ducting, plumbing, wiring—to pass through freely without cutting, drilling, or notching. This eliminates many installation constraints and gives builders more freedom to design open-concept spaces without unnecessary bulkheads or dropped ceilings. Homes benefit from stronger, straighter floors and faster installation times with fewer on-site adjustments.

The ability to span long distances also reduces the need for interior bearing walls, making it easier to achieve large living areas, tall basements, and versatile floor plans.

Why Floor Trusses Come Out on Top

While each floor system has its place, floor trusses consistently offer the best balance of strength, efficiency, and design flexibility—especially for modern prefab and custom homes. Builders appreciate the speed and accuracy of pre-engineered components, and homeowners enjoy quieter, more stable floors with fewer long-term issues.