I am remodelling a bathroom and completely gutted it. I have 3/4 inch subfloor down and will be putting 1/2 underlayment then tile. When is the best time to put up drywall on the walls. Should I put up drywall before or after the underlayment or does it matter? What I've read is to keep the drywall 1/4 inch up off the floor but don't know if that is subfloor, underlayment, or finished floor. Thanks.