Machine Rated Lumber Makes a Lot of Cents
Machine Rated Lumber Makes a Lot of Cents
deal with lumber defects that can affect connector
plate teeth embedment at critical joints.
It’s one thing to have a salesperson from an MSR producer tell you the advantages of using MSR lumber in your production process. It’s an entirely different thing—and much more persuasive—to have four veteran component manufacturers (CMs) give you the reasons they’re convinced it’s better than visually graded lumber.
Jess Lohse, president of Rocky Mountain Truss Co.; Jack Littfin, CEO and founder of Littfin Lumber; Dennis Westhoff, President of Lumber Specialties; and Tim W. Riegel, PE, Engineering Manager for Rigidply Rafters, provided their perspectives on when and why they use MSR instead of visually graded lumber. They focused on three main areas: the gains in efficiency in their production processes, the opportunities MSR creates due to its quality and consistency, and the advantages of having known and reliable lumber design values.
The Efficiency of MSR
“I think one of the greatest advantages of MSR is how it makes my production process more efficient,” said Littfin, who uses MSR lumber in almost all of his roof trusses. All the CMs agreed that more consistent lumber quality not only increased the amount of lumber they could use in the manufactured products for which it was purchased, but it also reduced production times due to less material handling. Westhoff explained, “one reason we use only MSR lumber is because it has drastically reduced the rate at which we have to cull lumber or rebuild trusses due to lumber defects.”
In addition to improving production efficiency, MSR also can contribute to the efficiency of the trusses themselves. “Because of the improved quality characteristics of MSR lumber, such as reduced wane of lumber at the joints, we are less likely to upsize our plates at the jig and our plate costs are accurate to design,” said Lohse. The CMs agreed that while the cost of MSR is higher, there were many ways to make back that cost, including the consistent ability to use smaller plates.
The Quality of MSR
Beyond lowering production costs, one of the biggest factors these CMs identified as a benefit of using MSR is reduced truss bracing. “Savings in the cost of bracing material for our customers, not to mention the reduction in the risk of injury from having to install less bracing, is one of the major reasons why we use MSR,” said Riegel. “It takes some time, but it isn’t difficult to convince your customers to embrace and pay for trusses made from MSR when they realize the cost benefits on the jobsite.”
Related to this is the increased bearing capacity MSR realizes through higher Fc| (compression perpendicular to grain) values. “This does require working with the customer, but we can usually convince them to use MSR in the top plate of the walls and eliminate a ply in a multi-ply girder truss in the process,” said Riegel.
There’s one last benefit the CMs have found to the quality and consistency of MSR. “When we looked at it, we found our rate of field repairs went down significantly when we switched to all MSR lumber,” said Westhoff. “I think a big part of that was we had less breakage from roll-off deliveries.”
The Reliability of MSR
The CMs agreed the value of having known and reliable lumber strength properties could not be overstated. “The lumber industry has gone down the path of trying to shift the risks of the structural performance of visually graded lumber onto end users like us,” said Lohse. He pointed out this has been a major challenge for members of the SBCA Board of Directors and is an ongoing battle. “The problem is we aren’t lumber graders, and that is far outside our scope of work.”
In the end, the CMs agreed that MSR allows them to achieve more accurate truss designs. “In most cases, you have greater assurance that what you are asking the lumber to do in a particular truss design [is possible] because each piece of lumber has been tested and verified to have at least the bending and elasticity strength properties printed on the grade stamp,” said Littfin.
When to Use MSR
Though the CMs agreed these were the advantages they realized through the use of MSR versus visually graded lumber, no two CMs took exactly the same approach to using MSR. “We use only MSR lumber in all applications because it’s easy for us to get and it makes our entire process more efficient than if we carried more grades,” said Westoff. “We use primarily MSR in our roof trusses, particularly wides in our top and bottom chords of our longer span trusses,” said Littfin. “We still use visually graded in webs and smaller trusses like jacks,” he adds, “because the savings really isn’t there for those applications.” Riegel, too, uses both. “We use two main grades of MSR for most products,” said Riegel, “though availability and price can play a role in what we purchase and use.”
In the end, these CMs choose to use MSR the way they do because they’ve found it reduces their costs and allows them to produce a more consistent, higher quality product, to the satisfaction of their customers.