Analyzing Substitutes for 2x4 SP Nos. 2 & 3

Originally published by: SBCAJanuary 30, 2012

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A key question that has been raised several times is, "What are the substitutes for truss designs that have used the existing 2x4 SP No. 2, when the new design values go into effect on June 1,2012?" One option is to specify a larger size and/or higher grade of visually graded SP lumber.  Another option is to specify mechanically graded lumber which includes Machine Stress Rated (MSR) and Machine Evaluated Lumber (MEL):

  1. 2x4 SP No. 2 can be replaced by:
    1. 2x6 SP No. 2 
    2. 2x4 SP No. 1 Non-dense and better SP visual grades.
    3. 2x4  MSR/MEL grades shown below:


       

    4. These are direct substitutes for 2x4 SP No. 2, but not all of the possible MSR/MEL grades will be produced.  The marketplace will eventually determine the most common grades.
    5. 1500f-1.6ER MSR and M-38 MEL are the closest direct substitutes for the current design values associated with SP No. 2 2x4s.
       
  2. 2x4 SP No. 3 and Stud grades can be replaced by:
    1. 2x6 SP No. 3
    2. 2x4 SP No. 2 Non-Dense and better SP visual grades
    3. 2x4 SP MSR/MEL grades shown below:


       

    4. These are direct substitutes for 2x4 SP No. 3, but not all of the possible MSR/MEL grades will be produced.  The marketplace will eventually determine the most common grades.
    5. 850f-1.4ER MSR and M-33 MEL are the closest direct substitutes for the current design values associated with 2x4 SP No. 3 and Stud 2x4s.