11 7/8" TJI55QE 1

[SteelPE]

I am trying to add a new large RTU to an existing building. The building has wood roof joists supported by steel girders. The building was built in 1994 and we have a set of design documents from when they built the building (although they are very water stained and damaged).

The existing drawings call for 11 7/8” TJI/55QE wood joists at 32” o.c. and 11 7/8” TJI/35 wood joists at 24” o.c. (in different areas of the building).

What could the QE in the joist tag stand for? I have literature from truss joist for TJI/55 joists, but I have seen to this point tells me what QE could stand for.

 

[boo1]

http://www.scribd.com/doc/41753539/TJI-Residential-Catalog-Feb-1992#scribd

 

[SteelPE]

boo1,

I have that document already, does it say in there what QE could stand for? I see DF and SP but not QE.

 

[Triangled]

Have never seen the QE designation, but, I seem to remember that back then one could get the same TJIs with either microlam or solid sawn chords (SP or DF etc), and consequently, I think, different moment and deflection capacities. I know also that they'd often differentiate different grades of microlam by reference to the Modulus of Elasticity, E. ...wondering if the water stains somehow obscured a reference to 2.0E or 2E or ?E or similar.

 

[Triangled]

from an old TJ guy from memory:
"Have you heard of this..."
"Never. It's a misprint of 550e. Which designated osb Web and lower moe. 2.0 instead of base 2.2 I believe."

from another old TJ guy:
"It’s a TJI 55OE. Not “Q”."

 

[msquared48]

My first take was 550 too. Sometimes transcription is a b×=%€.

Mike McCann, PE, SE (WA)

 

[SteelPE]

Well, I guess I'm and idiot because now that I look at the drawings the little line that forms the Q is going in the wrong direction and must have some erroneous mark on the drawing or something created by the water stain.