Thanks all for your valuable input! Learnimg much through this experience. I'm sticking by reinforcing all the trusses, will have to see which way the owner will want to proceed.
mssquared48 Why would they mix rough cut and dimensional? Was that common back in the day? This is a pic of the top chord, albeit the adjacent truss but near same end. It shows a gap between the outer ply at bottom... This is also the truss where the water damage...
The owner's asking about the "required torque" but I can't find where that would be applicable (hence the question). I am suggesting 1/4 to 1/2 turn of the nut, starting in middle where there's the least amount of axial load, proceeding symmetrically to outer bearing locations, and making a few...
How much torque would you need to retighten the tension rods?
I did analyze the member but without taking a specimen for eval on the wood I don't know for sure if it would work. Needed DF No. 1 or better. Also, the dead/collateral load is more what was there originally with HVAC, stage...
OK, I had a hard time justifying the top chord bearing. Assumed it wasn't when I modeled it, but didn't know why they'd pocket it in the brick (except for stability).
Going to recommend reinforcing the bottom chord, repairing connections, investigating the plaster for loose pieces. Then we...
Here's a pic of the gap in the top chord bearing at brick. The outer ply has slipped to be offset-vertically from the others.http://files.engineering.com/getfile.aspx?folder=7c6c84d7-964a-4eed-bb0d-0078da57cfb1&file=top_chord_brg_gap.jpg
I reinspected the trusses that are accessible (about half of total) Found three connections in bottom chord where the plies were bolted together (staggered 18" o.c.) and bolt was too close to the end of the ply and thus failed. See pic with the gap in the ply. There's likely more at the inner...
Thanks all for yout input, will keep you posted.
JAE the owner and I discussed a similar fix at the original inspection, using a steel truss conficuration over each existing. If it comes to that it's good to know it's feasible.
OK so connections, I did see some gaps (not large, maybe 1/4") between the the bottom of the top chord and the angled 4x webs which I assume to be s result of the rotation due to deflection. I can clearly see the rods and threaded portion with nut above the top chord (at least in some areas)...
The re-roof was around 2003 and the owner is trying to find out what (if any) of the existing was removed prior to the new membrane install. From the attic/underside the original planks are visible.
Without any forensic structural engineering experience I've been asked to look into an HVAC remodel on a roof with problems. The building is a 90 year old theater with wood trusses spanning 50' between brick piers, 13'6" on center, about 4' tall, Howe style (I think, and top chord bearing from...