Truss Wood 2

[Wbruseski]

I am checking the bending stress on a truss overhang. Can anyone tell me the types of lumber that are typically used in truss design? The truss drawings are unavailable. I figured it's probably Southern Pine or Spruce-Pine-Fur. The project is in Florida. I will of course be conservative if I cannot narrow it down further. Of these types, it "construction grade" always used? What is the lowest grade used for truss design? Thank you for your input.

 

[LPPE]

Do you have access to the truss? If so, there may be grade stamps on the chords. Typically web members are a lower grade than the top and bottom chords. I cant help you on what species, though. I'm in the Northeast and we use DFL.

 

[blmcghee]

try your State Natural Resources Dept. for wood type. They may have a local agent who can can look at the wood and tell you exactly what kind it is.With this information specifications will bve easy to determine.

 

[bb29510]

Go to

http://www.chambertruss.com

they are in fla too. Very information page.

 

[dik]

Could be anything... but, in these environs... they use machine stress graded lumber. The material is run through a machine that flexes it and determines the stress level to use it at.

 

[Ron]

Most common truss material used in Florida is Southern Yellow Pine (SYP). Typical grading for trusses is No. 2-KD for top and bottom chords, No. 3 for diagonals.

 

[Wbruseski]

Ron,
Thanks for the info.

I do know that it is Southern Yellow Pine. Is this the same as "Southern Pine" in the NDS for Wood Construction? What is the "KD" in No.2-KD?

 

[Ron]

Wbruseski...yes, you can use the same material properties. The KD means Kiln Dried, which is a slightly higher grade designation.

 

[Trussdoc]

You may benefit from contacting Southern Forest Products Assn. 504 443 4464