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RE: Use of Collar Ties in Light Frame Wo

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Dennis,

I think that the problem is at the connection of the rafter to the top of the 
wall/ceiling joists.  With the drop in the ridge being 2-inches, the end of 
the rafter (or wall) only has to move out 1/2".  This is hardly discernable 
to the naked eye.

I think that you are making a mistake in using collar ties that will not 
admit to a rational analysis.  While it is O.K. for a "dumb" carpenter to use 
these, "because that is the way he/she was taught," I think that you would be 
looking for "big trouble" if *you*, a professional engineer, used them and 
*knew* that they wouldn't comply with the engineered design requirements of 
the building code.  *You* know better!  *You* are educated!  *You* are a 
Professional Engineer!  *You* are capable of determining their adequacy!

I have crawled around enough in attics to know how difficult it is to really 
see things.  I have "crawling boards" that I use in attics so that my knees, 
elbows and whatnot don't have to support my body on ceiling joists.  I 
carry spare batteries and a spare bulb as on more than one occasion I had 
to replace one or the other in the attic.  With a 3:12 slope, you are lucky 
if you can get within 4-feet of the wall lying flat.  I don't know many 
people who have 4-foot long arms that can clear away insulation to see what 
is happening at the wall plate.  If you carry a toy rake, you can rake away 
some insulation, but still can't get close enough to see what is happening.  
With only a 1/2" movement required, the nail between the rafter and ceiling 
joist could be bent and the failure not visible.  I have seen at least one 
case where a nail bent and pulled out of a piece of wood and still remained 
in the joint between the two pieces it was tieing together.  (I have a photo 
of it, but don't remember the project, and, hence, where the photo is.)  
Without actually being able to look in the joint and seeing the bent nail, 
there was no other indication of what happened.

The white cellulose insulation that is common today frequently covers the 
ceiling joists and "educated" feet (or knees) have to be used to determine 
the condition of the joists.

Hope this helps.

Roger Turk

Dennis Wish wrote:

. > Roger,

. > I'm listening - where do you believe the problem might be or what I might 
. > do to find it. I believe the only structural problem is the ceiling. There
. > appears to be no other indication on the exterior of the building to
. > indicate a wall out of plumb, a crack in any of the stucco to suggest that
. > the rafter tails are pushing through (not nailed to the rafter ties).
. > I just don't see it. The rafters are sized properly if considered simply
. > supported. Even a 25'-0" long 2x6 rafter tie is appropriate for no load. I
. > just don't see were there is a problem other that the cracked ridge board
. > which you believe is non-structural and the ceiling deflection which I
. > believe I adequately covered.

. > Am I really missing something here or attempting to condemn conventional
. > construction for performing within its limits. please be more specific.
. > If anyone else see's something I am missing, please let me know!!!

. > Thanks

. > Dennis

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