I am installing 3 1/4 inch cherry hardwood in my living room and will use black paper under it. Over the infloor heating in the main floor master bedrooom I already installed engineered floating flooring , gluing the the joints togeather . I also used black paper in this room and used tuck taper to seal the overlapped joints . LATER ! I read the directions which states I should use a specific type of foam under the flooring . The floor is nice and warm and I do not notice any "slaps" or wobbles etc as I walk over it . The floor is 15/16 chipboard then I installed ,glued and screwed , 3/8 plywood over this . Does anyone know of any problems I may encounter by doing the installation with only the black paper ??