I have removed plaster from walls and ceilings and have installed new recessed lights in the ceiling. I installed the kind that was safe to use next to insulation. Now I am going to install 4 or 6 mil vapor barrier on the ceiling. My question is how close can I have the vapor barrier to the lights? It would be nice to have it sealed tight but not sure what to do.

Thanks

 

There are a few things to consider. First I am going to give the references to the code pertaining to the NEC. Second my recommendation. Third, is up to you do decipher.

410.XI covers some of your question.

(A). Combustible Materials. Luminaries (fixtures) shall not be installed So That adjacent combustible material will not be subjected to temperatures in excess of 90'C (194'F).

A letter from the manufacture should help for future problems, Stating that the fixture will not reach the 90'C temp, if not then no, it can not lay on the fixture. But then 410.66(A)(2)States(2) Type IC. A recessed luminaire (fixture) that is identified for contact with insulation, Type IC, shall be permitted to be in contact with combustible materials at recessed parts, points of support, and portions passing through or finishing off the opening in the building structure.

Now follow;

410.68
Luminaires (fixtures) shall be constructed so that adjacent combustible material is not subject to temperatures in excess of 90°C (194°F).

This tells me that the manufacture can not make a fixture of the recessed type that exceed 90'C....

My problem with giving you a "yes"/"no" is I don't want to be the one to decide if the plastic barriar is or is not going to catch fire I am trying not to be unreasonable just Cautious.