Agricultural and Biosystems Engineering
Buildings that have been exposed to flood wa¬ters need to be evaluated for the extent of damage and the amount of cleanup and repairs necessary to restore them to a useable condition. The first thing to do with a building that has survived a flood is to check its structural strength. If the building has been moved, shifted, or twisted, it may not be safe to enter. Check the foundation, sill, plate, roof supports, and walls for damage. If there is extensive damage to the building, it probably will be less expensive to tear it down and start again with a new building as compared to attempting to repair the damaged structure. A “rule of thumb” is that if it costs over 60% to repair and restore, then it is usually best to build new.
Durland, G.R. (Bob), "After a Flood: Salvaging Flood-damaged Buildings" (2002). SDSU Extension Extra Archives. 12.