i was told here that underlayment grade plywood will be a significant expense in the overall installation of glue-down vinyl ... to be honest i don't even understand why i need the underlayment ( i am working right now to find somebody who would remove the carpet so i can get a closer look at subfloor, without actually committing to installation - most of them only will remove the carpet if i also buy a new floor installation from them ) perhaps i could remove the carpet myself ? i just don't want to break my neck dragging it downstairs to the basement because the carpet is not really that old and i'm thinking of putting it to use in basement gym. could i do it myself ? anyway assuming i need the underlayment 1/4" plywood what would make such plywood "underlayment grade" ? i recently bought some 1/4" plywood to make a box for my TV when moving - the plywood was fairly cheap and the TV was very well protected. i don't think it was "underlayment grade" ? but what does it mean anyway ?