Walk it. Bounce on it a little. Any flex or bounce means the substrate isn't solid enough for tile — you'll need to add cement backer board or self-leveling compound first. Tile needs a dead-still surface. If the floor moves, the tile will eventually crack.

Sometimes, yes — but only if the existing tile is completely solid, fully bonded, and the added height won't cause problems with doors, transitions, or drain heights. We always check first. Installing over loose or hollow tile is just stacking one problem on top of another.

It depends on the tile. Rectified tile (machine-cut with very precise edges) can go as tight as 1/16". Handmade or natural stone tile needs more — usually 3/16" to 1/4" — because the edges aren't perfectly uniform. Your tile installer should match the joint width to the tile, not just default to one size.

A standard bathroom floor and shower surround is typically a 3–5 day project when done properly — and that's with cure time built in. If someone's quoting you a one-day tile job on a full bathroom, ask them how they're handling the cure window. The answer tells you a lot.

For backsplashes, laundry room floors, small bathroom updates — DIY is doable with some patience. For full shower surrounds, wet areas, or anything with complex patterns or large-format tile, we'd strongly encourage calling a pro. The margin for error is small, and water damage is expensive. We've seen $4,000 tile jobs turn into $15,000 water remediation projects. It happens more than you'd think.