Calling them “the most comprehensive lumber span calculators we’ve ever produced”, the Pacific Lumber Inspection Bureau (PLIB) has unveiled three new online calculators that provide users with structural lumber design tools digital previously unavailable.
PLIB’s design value comparison calculator, the first of its kind, allows users to determine applicable design values for an unlimited set of species combinations, an invaluable tool in today’s market, where multiple species are often delivered on construction sites.
“The problem of delivering multiple species to job sites is not new,” explained PLIB President Jeff Fantozzi, “but with the increased use of imported timber in recent years, we are getting more and more calls for help from code officials, labor superintendents and engineers who are trying to determine applicable design values for species and groups of species they have not encountered before.
In 2021, challenges created by the problem of multi-species presence on construction sites emerged in the state of North Carolina, resulting in disruptions at construction sites and in distribution yards. The complexity of determining common design values for a wide variety of species combinations has made it difficult for end users and code maintainers to use mixed species. The need for more user-friendly design aids was obvious.
“We developed the Design Value Comparison Calculator in response to this issue specifically,” Fantozzi said.
With the tool, users can enter any number of quality/species/region combinations they see on quality stamps to generate a table showing design values and specific gravity values for each individual group. , while also highlighting the values that apply to the group as a whole. According to Henry Morris, Director of Engineering for PLIB, “The tool saves timber designers, timber brokers and code maintainers hours – of time they previously spent extracting data from sheets calculators or printed tables. This greatly simplifies the use of virtually any structural lumber one might encounter in North American markets.
PLIB’s new Span Options Calculator allows users for the first time to generate a set of lumber size options capable of achieving spans based on user-entered design criteria and sizing information. species. A new Maximum Span Calculator provides the maximum span length, along with values for bending strength, shear strength, and bearing strength, for any combination of grade and species or species group based on design criteria entered by the user. Both range calculators are derived from the identical data set used in the Design Value Comparison Calculator.
The calculators include data for virtually every softwood lumber species that could be found in North America, as well as a wide range of hardwood species that could potentially be used in structural applications. The wide range of species choices, along with the ability to compare multiple combinations of options, make these digital wood design calculators the first of their kind and extremely useful tools for wood users.
Calculators can be found on both desktop and mobile versions of the PLIB website at www.plib.org/resources/calculators. They are accessible to the public and their use is free.
“PLIB is committed to supporting the continued and expanded use of wood in residential and commercial construction,” said Fantozzi, “The development of these calculators and their accessibility to all clearly contributes to fulfilling this commitment.”