For a three-span continuous beam, with deflection limited to L/360 of the span length, the minimum required cross-section area (A) of a joist section is in ?2. (Reference equation:
(:Fv'=0.9wl/bd(q)=150l b/f t²
Spacing of joist (s)=20 in
Fv'=190 psi
Joist span length (I)=48 in