Manufacturing

Lumber Design Values

No matter the species, component manufacturers (CMs) purchase and rely on the accuracy and reliability of many different lumber design properties, including: bending (Fb); shear parallel to grain (Fv), compression perpendicular to grain (Fc^), compression parallel to grain (Fc), tension parallel to grain (Ft), and modulus of elasticity (E and Emin).

Last June, Truss Components of Washington started doing something unconventional: holding regular meetings of production, design and office employees. General Manager Chad Johnson and Production Manager William Blankenship reflected on their six-month-old experiment, sharing why and how they brought these groups together and what the meetings have accomplished.

Just as there’s no one-size-fits-all housing solution, there’s no one-size-fits-all business model for CMs. For the sky-high prices and seasonal swings in the Greater Yellowstone area, tiny houses are uniquely suited to the needs of both buyers and builders.
Teton Truss Tiny Houses
Question: 

I would like to know the proper storage and shipping of wood trusses.

Question: 

When webs are cut is it alright that sometimes the grade mark is removed? From a liability standpoint, what is the rule with grade marks and web members?

Question: 

The grading rules usually permit some percentage of visually graded lumber to be below grade – I believe it is 5%. ANSI/TPI 1 requires that all lumber used in trusses be of the grade specified by the truss design. A strict interpretation of ANSI/TPI 1 would require that the fabricator cull the 5% that is off grade. What are your thoughts on this?

Question: 

If the truss design drawing specifies using 2x4 1650F SPF, can 2x4 No. 2 southern pine be used instead? What are some things that need to be checked?

Question: 

IBC 2012/2015 2303.4.6 and IBC 2012/2015 2303.4.7 state: 
2303.4.6 TPI 1 specifications. In addition to Sections 2303.4.1 through 2303.4.5, the design, manufacture and quality assurance of metal-plate-connected wood trusses shall be in accordance with TPI 1. Job-site inspections shall be in compliance with Section 110.4, as applicable.

Question: 

If you have the condition where you are out by the max tolerances of 1/2 in., how do you correct the situation? Do you shim the truss from the bottom? Shim from the top? I will assume you do not shave the truss off. What is the published corrective action for situations that cannot handle the variation in truss height?

Question: 

I am a structural engineer on a project with a wood trussed roof. I have noticed some variations in the peak height in a run of identical trusses. Do you have any information on tolerances for the final dimensions of manufactured trusses?