dimensioned lumber as diaphragms 1

[bylar]

Can anyone supply me with good sound information on using dimensioned lumber as diaphragms. I had some information years back but I cannot seem to relocate it. I have many documents on plywood as diaphragms but I need to see the possibility of using dimensioned lumber.

I have been intrigued over the discussion on STAAD.]

I have it. I use it but I don't trust it and i adhor REI and their arrogance.

 

[oldrunner]

I don't quite understand your question. Do you mean something like a solid roof or floor made up of 2x members on edge - (or even 1" members)that is something like a bridge deck? Something like this also might be considered a rigid diaphragm. You should be aware that the rigid versus flexible diaphragms of plywood generated lots of discussion on the SEAINT Listserver over the past few years and comments as recent as last week were still being made.

 

[ofthesea]

See 1997 UBC Section 2315, especially see 2315.5.4 for heavy wood panel diaphragms. 2315.5.4 gives some recommendations for diaphragms using 2x or 1x dimensional lumber.

The UBC also allows dimensional lumber to be used as a diaphragm if "calculated by principles of mechanics" This leaves the door open for some engineering creativity.

Good Luck

 

[BuddyShowalter]

AF&PA's Wood Frame Construction Manual for One- and Two- Family Dwellings, SBC High Wind Edition, Table 3B contains shear capacities for 5/8" lumber sheathing attached straight and diagonally. Visit

http://www.awc.org/Standards/wfcm.html

for more information.

The 1997 Uniform Building Code contains design capacities for diagonally sheathed lumber diaphragms in section 2315.3. Visit

http://www.awc.org/Codes/bldgcode.html

for links to ICBO.

The International Building Code contains design capacities for diagonally sheathed lumber diaphragms in section 2306.3 Wood Diaphragms. Visit

http://www.awc.org/Codes/bldgcode.html

for links to ICC.

"Analysis Methods for Horizontal Wood Diaphragms" by Jephcott and Dewdney from proceedings of a Workshop on Design of Horizontal Wood Diaphragms (ATC-7-1) conducted by Applied Technology Council on November 19-20, 1980 (25 pages). Visit their website at

http://www.atcouncil.org/

to order.

HTH

Buddy Showalter, P.E.
AF&PA/AWC

 

[bylar]

Thanks for all the help. We just switched to the IBC and I am still finding it hard to get the time to study it,

Byron