Most post-frame and pole buildings use lumber as the main material. If you’re building a new shed, barn, or hangar, do you know the lumber’s durability? Do you know if you’re using visual grade lumber or machine stress-rated lumber? Do you know the difference, or have you even heard of these two terms?
Visual Grade and Machine Stress-Rated Lumber Explained
Not all lumber is created equal. In the past two decades or so, lumber quality has waned considerably due to the proliferation of fast-growth, farmed lumber. Slower-growth, natural lumber, by contrast, is sturdier and lasts longer.
Wherever you acquire your lumber, it’s critical that the material undergoes machine testing. This is where the machine stress-rated (MSR) test enters the picture.
To evaluate the wood’s density, the MSR process uses sophisticated ultrasound equipment. Another variety of MSR testing includes a mechanical bending process. Both tests measure the amount of strength the wood can withstand.
Visual-grade (VG) lumber, by contrast, is an outdated method in which the lumber simply undergoes a visual inspection to determine its quality. Signs an inspector looks for include:
- Wood species
- Checks and splits
- Rot and decay
- Bark quality
- The position of holes and knots
It’s also common practice for some suppliers to designate lumber that failed machine testing as VG lumber.
According to the National Lumber Grading Association, MSR Lumber is about 25% stronger than its visual-grade counterpart. It’s absolutely vital to consider lumber strength when the construction needs to hold up against elements like wind, moisture, and hail.
We Only Use the Highest-Quality Lumber
Contact C&S Construction to schedule the construction of a new barn, shop, or building. We use the highest quality lumber to ensure the longevity of every one of our handiwork. Browse our gallery to see the professional craftsmanship of our work. Machine stress-rated lumber and visual grade lumber are vastly different, and we’re committed to using only the former.
Durable Lumber for all Residential & Business Construction
Serving customers from Pullman to Bonners Ferry and Wenatchee to Western Montana, including Spokane, Coeur D’Alene, Cheney, Pullman, Sandpoint, Wallace and the surrounding area since 1998