my basement is dry. i want to have finish half with a carpet and half with wood tiles. several questions: -is it wise to put the wood tiles directly on the concrete? will minor surface irregularities bother it? do i have to fix small (<1/8 inch) cracks in the slab? - i want to have a moisture barrier under the carpet. is this advisable, will it force me to put a sub-floor in? i have 7 1/2 to 8 feet of height but would like to keep as much as possible.