ICC-ES truss plates

[TheMoonlitKnight]

Hi, All. I need to design a solid-sawn truss-girder and was checking out the ICC-ES report on a few different types of MiTek truss plates. Based on reading the report, it seems pretty easy to size these plates - my previous understanding was that these tooth-like plates were only being used by truss manufacturers and not available for retail purchase. If they are available, is there anything to watch out for that isn't covered in the ICC-ES reports?

 

[RFreund]

How are you fastening (pressing) them to the trusses?

EIT

http://www.HowToEngineer.com

 

[TheMoonlitKnight]

Big, bold note on the drawings:

"All truss plates are pressed into the wood for the full depth of their teeth by
hydraulic-platen embedment presses, multiple roller presses that use partial
embedment followed by full-embedment rollers, or combinations of partial
embedment roller presses and hydraulic-platen presses that feed trusses into a
stationary finish roller press. Trusses must be assembled within the tolerances
provided by the Truss Plate Institute’s Quality Criteria for Metal Plate Connected
Wood Trusses, shown as Chapter 3 in ANSI/TPI 1 National Design Standard for
Metal Plate Connected Wood Truss Construction."

It comes directly from the ICC-ES report.

 

[RFreund]

I see I thought this was a different application or a situation where they did not have this type of equipment. "only being used by truss manufacturers" threw me off.

EIT

http://www.HowToEngineer.com

 

[SLTA]

I used to work at a place that manufactured trusses, and we always used the proprietary software from MiTek or similar to design the truss, and their engineer would stamp them. Load values for the plates always seemed rather hush-hush. "For retail purchase" indicates you're not going to manufacture the truss - why not have the folks who will, design it, too?

 

[TheMoonlitKnight]

RFreund: I wonder if when they call Simpson to order the plates, that Simpson will require that they are certified by ANSI/TPI to manufacturer the trusses?

slta: I thought there was a hush-hush aspect too, until I noticed in another post that the ICC-ES reports required the tabulation of allowable shear and tension forces for the plates and the lateral tooth to wood resistance.

Some back-story: It is a fire damage job of a single family home (a mansion of a house). The fire charred a portion of a truss-girder and some adjacent trusses.

We have never worked with this contractor before (we were recommended by somebody else), and he was not interested into getting a truss manufacturer involved as we initially requested. He essentially strong-armed my boss into agreeing to design a custom truss-girder to sister onto the existing one, among other, what I find to be, unreasonable requests. I have no idea why he didn't want to get a truss manufacturer involved as they are obviously very efficient at what they do.

I decided that, regardless of his preconceptions of how he was going to assemble the truss-girder, I was going to spec the assembly as if it were to be manufactured by a truss company. The allowable tolerances and quality of materials and assembly needs to match everything TPI specifies - no compromise on that part. I have a suspicion that he will realize that he can't do it as easily as he thought. I am interested to see how our closeout inspection will go...