This decision can only be made by the engineer performing the repairs. The rust should be removed down to sound metal with a wire brush and the section thickness measured with a micrometer. Grinding the rust off can be down; however, this may remove more material and result in thinner sections. If the rust exists along the full length of the member, this should be done at different locations to ensure and accurate cross section for analysis.

It will not be possible to tell the difference between a K-Series and KCS-Series joist with field measurements. The most likely difference between the two joist Series will be the difference in the interior diagonal web sizes. Because KCS-Series joist webs are designed for a constant shear and full load reversal, the interior webs will most likely all be the same angle size. For K-Series joists, the interior diagonal angles will most likely be different angle sizes.

Watch our KCS-Series Joist video.