Diy Insulate Garage Door . Rolls of reflective foil insulation are a good option for standard metal garage doors. Doing a second layer of foam board will increase the effectiveness of the insulation. DIY Garage Door Insulation Installation in Steamy Arizona Insulfoam from www.insulfoam.com 3 steps & most effective way to insulate your garage door to reduce heat gain: It's almost too easy, but well worth it! Nasa tech garage door insulation kit.