Heated Raised Floor?

I will be in the process of installing an electric radiant floor on a raised/platform floor. In the past I have had problems with the pipes under the floor freezing during the winter. Do you think the radiant floor pad will induce enough heat to prevent future freeze ups? The floor is raised by 2x8'S on end with 3/4 inch plywood subfloor. I am planning on tiling on top of this. There is currently heat tape on the pipes....but to insulate area properly would mean to rip ou the subfloor and toilet to get at the pipes. Any suggestions or agreements? I am also planning on venting the one side of the platform to allow the cold air to escape and not aculate. This will be covered with an ordinary grate. Thanks