The foil can then be rolled back to the corner and across the back for approximately 3 inches and taped into place.  These back tabs will be covered by the sheets that go across the back.

 

Once the side pieces are in place, a single sheet of foil will go up on each side across the back, across the top, and down the front so as to rest on that lip above the doors.    This last edge must not cover the light or thermostat bulb, but does not need to be taped.  Smaller sheets should not be taped together since the tape might burn through and the foil could drop on the chickens.  The lengths of foil needed for the various ovens are indicated on the table above.  Those final sheets can be taped so as to keep neat.