In older homes, how can we check to see if there is already insulation in the wall cavities?
One easy way to determine if there is insulation in the wall cavities, or if they are empty, is to remove an electrical receptacle cover. Turn off the power to the circuit. Take a kitchen butter knife and carefully slide it along the outside of the electrical box and in the open cavity. If there is any insulation, you should be able to feel it when you slide the knife on the outside of the electrical box.
