An improved insulation system is used to insulate {HEAD ~ the roof} of {TAIL ~ a metal building} 
of
An improved insulation system is used to insulate { HEAD ~ the roof } of { TAIL ~ a metal building }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL