Re: Can 2x6 T&G roof or floor consider to be a diaphragm?

Ken

 

Are the 2x6's perpendicular to framing or diagonal ?

 

Roof

perpendicular   = 100plf

 diagonal        =  250plf

 

Floor

perpendicular     = 100plf

perpendicular     = 500plf

w/ wood flooring

 

 diagonal            =  250plf

w/ wood flooring  =  600plf

 

 

I believe it is 2-16d's @ each support min.

2007 CHBC Table 8-8A

 

Joe Venuti
Johnson & Nielsen Associates
Palm Springs, CA

 

In a message dated 11/18/2009 3:43:03 A.M. Pacific Standard Time, mStuart@cmxengineering.com writes:

It is very likely that the existing deck was horizontally spiked together such that the spikes plus the T&G resistance will enable the deck to act as a diaphragm.

 

D. Matthew Stuart, P.E., S.E., F.ASCE, SECB

Senior Project Manager

Structural Department

Associate

Engineers and Consultants - CMX

200 Route 9

Manalapan, NJ 07726

732-577-9000 (Ext. 308)

908-309-8657 (Cell)

732-298-9441 (Fax)

mstuart@CMXEngineering.com

 

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From: ken ng [mailto:zy7up@yahoo.com]
Sent: Wednesday, November 18, 2009 1:07 AM
To: seaint@seaint.org
Subject: Can 2x6 T&G roof or floor consider to be a diaphragm?

 

1. 1.  I have a 1945 building and it has 2x6 T&G (2" Vert. and 6" Horiz) roof and the floor is nailed directly to beams at 54"o.c.  Can I consider these are flexural diaphragms with 54" existing nail spacing?

 

2.  2.  What about additional floor or roof joists that were added @ 18" o.c. with new nails at 18" o.c.  Will this be considered to be a diaphragm?

 

3.   3.  Or ½" plywood shall be added on top of existing 2x6 T&G?

 

4. 4.   The drawing plan called out some live load for Storage in 1945.  However the hand created drawing was not so clear to read.  I could not read the numbers if it's 50#, 75#, 100#, or 125#.  Does anyone know what was the 1945 UBC required for this year?