Here are more photos since last time I had trouble with uploading them in photobucket.
As I said before the walls and ceiling were covered with plastic and then strips of wood were screwed. The photo below shows the covered ceiling.
Here underneath, the unpainted strip is to support the main lights of the room. I have another which isn't present in the picture.
Then I cut the jablo to size and filled the space between the wooden strips.
Then I covered everything with plastic again.
including the ceiling....
and then on top I nailed the plastic panels..
I will post more photos as I go along...Now the plastic panels are all ready.