Robert, that is about what I was trying to do 30 years ago. The duct tape may scorch. The weight of all of those tapes may add up.
For really light weight, I used cardboard covered with aluminum foil and tiny pieces of duct tape. That works for a while. A piece of Masonite works pretty good, also.
It kind of depends on what you are trying to accomplish. For summer use, you probably don't really need any board underneath the burner, or a piece of aluminum foil at most. For winter snow, the Masonite works, but you only need about 6"x6", and then cover it with aluminum foil. Basically, that is just to keep the burner from melting its way down into the snow.