Hello, I'm remodeling my bathroom and have a quick question about the sub flooring. Right now I'm down to 1x10s that are nailed into the joists below. I'm planning on putting in tile. The question I have is: do I need additional sublfooring (plywood) over the 1x10s before I put down hardiboard (underlayment?) for the tile, or can I just put the hardboard right down on the 1x10s? I've seen a few different things out there about this, but it might just be me misinterpreting. I'd like to not put the plywood down as it will make the finish grade of the tile a half-inch or more above the hardwood floor outside the bathroom...thoughts?
No you can not just lay tile board over it.
Those old boards flex and are never totally flat.
Tile board adds no strength to the subfloor.
What's the size, spacing and spans of the floor joist?
Going to have to add decking screws to those old boards and go over the floor with at least 1/2" A/C subfloor rated plywood.
Thin set under the 1/4 tile board.
A marble threshold in the middle of the door opening and tile up to it.
When posting in forums, letting us know your location will help others give better feedback/advice/solutions to your questions