Beam deflection refers to the bowing out of beams that can happen when stressed by heavy loads. While beam deflection looks scary, some amount of beam deflection is normal. According to RMI, beams are usually designed to accommodate deflection up to .55% of the beam’s length. To figure out what the allowable deflection is for your beams, take the beam’s length and divide it by 180. For a 96” beam, that comes to .53” of allowable deflection.
To then determine whether or not your current deflection falls within the acceptable range, measure the beam’s distance from the floor at the very end of the beam and at the middle of the beam. If the difference in distance is less than .53”, you’re good to go. If not, your beams may be overloaded. Remember to consult a material handling professional if you have any questions about beam deflection in your application.