Unit support stand platform seismic restraint this item refers to the device that the air conditioner or heater sits upon, whether a small concrete slab that is tilted, undercut or damaged and unstable or whether the unit sits on a metal stand that is unstable or not secured to the roof. Many possibilities of an unstable or damaged mounting device exist. The unit may be placed on a damaged wood framed stand in a closet, in a garage or at some other location within the building, such as in the attic. It is important that the unit be secure to prevent damage to electrical lines and conduits and pipes carrying gasses, as well as damage to ducting. Pack dirt or concrete under mounting slabs that are undercut (after leveling if necessary) and replace slabs that are damaged beyond repair. Roof mounted units should be strapped to their stands, to prevent movement during earthquakes and normal unit vibrations. Contact a handyman service, a home repair service or an air conditioning contractor for assistance if necessary.