another question regarding h-series joists

huangyhg

another question regarding h-series joists
i forgot to ask this in my previous thread, but from the 75 year manual, what is the equation for the approximate moment of inertia of h-series joists using the allowable live load?  thanks

i have never herd of this, but on page xx, there is a table of effective moment of inertia of standard sji (j & h)joists. per the table, for a 20h6, the effective i = 122.8 the effective moment of inertia is the joist moment of inertia divided by 1.15.