American Lumber: SPFs is the Clear Choice for USA

By Kim Drew

If you’ve been around the construction or lumber business for any amount of time, you’ve probably bumped into this alphabet soup before: an SPF or SPFs notation on the grade stamp. And maybe you’ve even had someone tell you there’s a big difference in strength, or that you should always go with SPF over SPFs. Well, it's time to set the record straight, because those old myths just don’t hold up anymore.

Grab a cup of coffee (or your favorite energy drink), because we’re diving into some long-overdue truths about SPFs-stamped lumber and why, if you're a builder, contractor, or just a hands-on DIY'er, SPFs might actually be the smarter, stronger, and more local choice.

Why SPFs Lumber Is the Clear Choice Over SPF: Clearing Up the Confusion Once and For All

First Things First: What Even Is SPFs?

Let’s decode this lumber lingo. SPF stands for Spruce-Pine-Fir, which is a grouping of similar softwood species. SPFs stands for Spruce-Pine-Fir south. What’s the difference? It’s not the type of tree. It’s where the tree grew. The little “s” at the end tells you that the lumber was milled from logs harvested in the United States, south of the Canadian border. No “s”? That lumber is 100-percent from Canadian trees. Simple, right? Well, it should be. But this one-letter difference has caused decades of confusion.

Is Canadian SPF Stronger?

This myth has been floating around the industry for more than 30 years, ever since new lumber strength values were implemented separately in the U.S. and Canada.

Here’s what really happened: back in the early ’90s, both countries decided to re-test the strength of their lumber. The U.S. went through its own sampling and testing protocol, and Canada did the same. As a result, the SPFs grouping ended up with slightly lower design values than SPF, even though—get this—they're often the exact same tree species, sometimes growing just yards apart, separated only by a line on a map.

“The idea that the same tree species growing within feet of each other, but separated by a border, and one being considered stronger, is absolutely ridiculous,” says Jeff Easterling, president of the Northeastern Lumber Manufacturers Association (NELMA). And he’s right.

Let’s Talk Numbers (and Real-Life Applications)

There are six lumber properties that testing assigns strength values to:

1. Fiber bending

2. Tension parallel to grain

3. Horizontal shear

4. Compression parallel to the grain

5. Compression perpendicular to the grain

6. Modulus of elasticity (a.k.a. how flexible the board is)

As stated above, yes, SPFs has different design values than SPF. But here’s the real kicker: For almost every typical construction use—especially repetitive use applications such as framing, wall studs, joists, and rafters—SPFs more than does the job. It’s not inferior, it’s just measured differently. If you’re doing basic framing work, SPFs is right there in the sweet spot of strength, usability, and availability.

SPFs is Graded Exactly the Same as SPF

Here's where some more confusion creeps in. People assume the grading systems are different between the U.S and Canada, but they’re not. Whether it's SPF or SPFs, construction-grade lumber (Select Structural, No. 1, No. 2, etc.) is graded using the same National Grading Rule criteria, administered by the American Lumber Standard Committee.

Translated: a No. 2 SPFs board is graded exactly the same way as a No. 2 SPF board. The standards, the quality control, the inspection—identical. The only difference is where the tree grew, and how that particular country did its strength testing.

SPFs is Already Everywhere—You Just Might Not Know It

Don’t let anyone tell you that SPFs is some fringe product only used by Northeast or Great Lakes traditionalists. Far from it.

Each year, about 2 billion board feet of SPFs lumber is produced and shipped throughout the U.S. from mills in the Northeast and Great Lakes regions. That’s a lot of framing, roofing, decking, and more happening with good ol’ American-grown SPFs.

And get this: Another 500 million board feet of SPFs lumber is actually produced in Canada. Yep. Canadian mills are also churning out SPFs-stamped lumber from logs harvested in the U.S. That alone should tell you how arbitrary this line-in-the-sand difference really is.

So, Why Pick SPFs?

Here are a few rock-solid reasons:

It’s American-Made. In an era when more folks want to support local and domestic products, SPFs is the obvious choice. It’s manufactured from logs grown and harvested right here in the U.S.A. Supporting the production of SPFs lumber translates directly to supporting United States lumber mills and their employees.

It Works Perfectly for Standard Building. Whether you’re building a home, a shed, or a home addition, SPFs has the strength you need. For repetitive framing systems, like wall studs or roof trusses, SPFs checks every box.

It’s Held to the Same Standards. SPFs lumber is graded to the exact same structural criteria as SPF. You're not getting a "lesser" product, you're getting a locally tested, locally proven one.

It’s Readily Available. Two billion board feet is a huge number. This lumber is in active use in most parts of the country, and your local yard is likely to have it ready to go.

It Helps End Confusion. When you choose SPFs and understand what it actually represents, you're helping push back against decades of misinformation in the building industry. Knowledge is power, and this knowledge supports local economies.

The Bottom Line: Don’t Be Fooled by One Letter

At the end of the day, SPFs is not just “good enough”—it’s the right choice for thousands of building applications. The myth that it's weaker or unfit for structural use is outdated, unfounded, and unsupported by the real facts.

If you’re a builder, contractor, or even a weekend DIY'er, understanding SPFs can help you make smarter purchasing decisions—ones that benefit your project and your bottom line.

Want to learn more and see the numbers for yourself? NELMA has released a free brochure titled The Facts About SPFs-Stamped Lumber to set the record straight. You can snag a copy at www.nelma.org.

Because when you strip away the misinformation and dig into the data, SPFs is more than just solid lumber: It’s a solid choice.