Tag Archives: Canadian SPF strength

Southern Pine is Not a Benefit!

Almost Anything Can be Sold as a Benefit

Over the years I have noticed one thing about sales people (and sales organizations), almost anything can be run up the flag pole as a benefit (oftentimes it is actually a feature) and if it is touted highly enough, a certain number of people will believe it.

Kind of reminds me of internet rumors.

I recently saw a quote produced for one of our clients by a competitor. The quote touted:

“ALL SOUTHERN PINE!   NO SPRUCE, NO WHITE PINE, NO HEM FIR *** BE SURE TO COMPARE!!!

Trusses #1 southern pine, all wall girts & roof purlins are 2×6 southern pine – BE SURE TO COMPARE!”

Sounds pretty darn important, doesn’t it? Southern Pine therefore must be stronger, right?

Wood Bending StrengthLet’s take a look at the facts. 2×6 #2 Southern Pine has a Fb (Fiberstress in Bending) value of 1000 inch-pounds. 1000 sounds like a pretty big number, so it must be the best. (You can check out these values for yourself at: https://www.southernpine.com/app/uploads/TABLE01_L1.pdf)

Well a fair amount of the framing lumber used in the United States is Canadian SPF (Spruce-Pine-Fir), which many people just refer to as ‘Spruce”. It turns out 2×6 #2 SPF has a Fb value of 1137.5 inch-pounds and 2×6 #2 Hem-Fir comes in at 1105! Both of them turn out to be stronger in bend than Southern Pine.

While I personally have not seen “White Pine” used as structural framing lumber, “Eastern White Pine” does have published structural values and a 2×6 would weigh in at only 747.5 inch-pounds.

Much of the Southern Pine grown today is harvested off farms where fast growth is the key to a good return on investment. Lumber from these tree lots tends to have very widely spaced growth rings. Some of these attributes resulted in Southern Pine strength values being degraded in recent years (here is an article I wrote pre-downgrade: https://www.hansenpolebuildings.com/2012/06/southern-pine/).

As far as workability, I’ve driven a few nails in my lifetime. I find SPF to be the most workable of all for being straight and easy to hand nail. Much of the Southern Pine I have used, had to be nailed up in a hurry, else it was prone to warp and try to twist itself into pretzels.