Stephen writes from Dallas, Texas: "I have rental houses with can lights. Is there a product that can retrofit an old can light that allows me to blow in insulation in the attic without worrying about contact to the can light?"

Answer: Lights must be IC rated for the insulation to come in contact with them. If the lights are not IC rated, the insulation must stay 3 inches away. If your can lights are not rated to be in contact with the insulation the only way you can put insulation over them is to build a box around them. The other option, of course, is to replace the lights.