Visual Grade Lumber Vs Machine Stress-Rated Lumber: What’s the Difference?

Visual Grade/Machine-Stress Rated LumberMost post-frame and pole buildings require the use of lumber. If you’re having a new shed, barn, or hangar built, do you know the durability of the lumber? 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 (VG) & Machine Stress-Rated Lumber (MSR) Explained

Not all lumber is created equal. In the past 20 years or so, lumber quality has deteriorated due to the rise of fast-growth, farmed lumber. Slower-growth, natural lumber, by contrast, is sturdier and lasts longer.

Wherever you acquire your lumber, it’s essential that the material undergoes machine testing. This is where the machine stress-rated test comes in.

To test the wood’s structure and density the MSR process uses ultrasound equipment. Another variety of MSR testing includes a sophisticated mechanical bending process. Both tests determine the amount of strength the wood can handle.

VG lumber, by contrast, is an outdated process in which the lumber simply undergoes a visual inspection to determine its quality. Signs an inspector looks for include:

  • Species of wood
  • Checks and splits
  • Decay
  • Quality of bark
  • The position of knots and holes

It’s also not uncommon for suppliers to label lumber that failed machine testing as VG lumber.

According to the National Lumber Grading Association, MSR Lumber is about 25% stronger than its VG counterpart. It should be pointed out that it is absolutely vital to consider lumber strength when the construction needs to withstand elements like wind and snow.

We Only Use the Best Lumber

Contact C&S Construction to schedule the construction of a new barn, shop, or building. We only use the highest quality lumber so we ensure the longevity of every one of our buildings. Visit our gallery to see the professional craftsmanship of our work. Machine-stress rated lumber and visual grade lumber are vastly different, and we only stick to the former.

Edited by Justin Vorhees

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