Recessed lights may look nice, but because of their construction they will extend into your attic space to allow for ventilation and room for wiring components. Most newer models will have a gasket that secures between the light fixture and the ceiling to prevent any air from the attic to leak out into the room itself, but over time these gaskets can come loose or deteriorate, and an air leak can form around the lighting fixture. If this occurs, there are ways to reseal the light and hold air in.
Determine the Fixture Type
There are two types of recessed lights: those that can make contact with insulating material and those that cannot. Recessed lights that allow for insulation to go directly on them will be labeled as "IC" fixtures. This distinction will be prominently displayed on the light and make it much easier to fix air leaks. Those that aren't distinguished as "IC fixtures" will get too hot and not have the proper sealing around them to safely put insulation directly on top of the opening without creating a fire hazard. If that is the case, additional measures must be taken to fix any air leaks that form.
IC Fixtures
An IC-rated recessed light requires only loose insulation to fix an air leak. Because the insulation can come in direct contact with the light, simply create a solid blanket of insulation material across the attic floor, running up flush with the recessed lighting fixture on all sides. This will prevent any air from traveling from the attic into the room itself and vice versa.
Non-IC Fixtures
Non-IC recessed light fixtures require some additional preparation and care to ensure there is no risk of fire. Because the fixtures can disperse so much heat around them inside the attic, it is important that no loose insulation comes within 3 inches of the fixture on all sides. Additionally, there can be no covering put directly over the fixture, as it requires room to vent off any hot air. To make up for these restrictions, use the floor joists already installed in the attic along two sides of the fixture. Using scrap wood, create a wall on the other two sides of the fixture, in essence boxing in the light, with the joists being two sides of that box. Make sure that the two walls that you install are at least 3 inches each away from the fixture, and use wood glue to secure them in place and eliminate any gaps. This will allow you to place loose insulation along the outside of each piece of wood, up to the 3 inches from the fixture. Note that this method won't completely eliminate air leaks if they occur directly around the fixture, but it will significantly cut down on the amount of air that reaches the light and seeps through.
Tags: loose insulation, around them, contact with, fixture sides, from attic