The flexible sheets have a width which is greater than {TAIL ~ the width} of the insulating boards so that {HEAD ~ longitudinally extending edge portions} of the sheets project outwardly from the edges of the insulating boards 
The flexible sheets have a width which is greater than { TAIL ~ the width } of the insulating boards so that { HEAD ~ longitudinally extending edge portions } of the sheets project outwardly from the edges of the insulating boards
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH