1. Make sure the railing manufacturer always performs project-specific engineering calculations.
2. Since vibration can occur on systems with longer structural members, make sure your post spacing is 48" on center or closer.
3. Consider strongly-welded systems in lieu of mechanically fastened railing to reduce or eliminate rattling.
4. Rethink systems with pass-through pickets. Even if the railing system's pickets are welded to the top and bottom rail, rattling or vibrations may still occur if the pickets are not welded to the "pass through" component.
5. Minimize whistling on mechanically fastened systems by placing snap-on covers on the bottom of vertical components (i.e. posts & pickets). Be sure a weep hole is present when these covers are used, in order to allow excess moisture to escape.