Curbless Entry and the Recessed Floor
Recessing a shower floor into the framing is the only honest way to get a genuinely flat entry. The detail worked through at walk in shower installation lakewood ca nexusphiladelphia is that recess, because a Lakewood shower on a wood framed floor cannot simply lose two inches of height without somebody looking at the joists first.
Where the Height Goes
A conventional shower gains height: the pan, the slope and the tile all sit on top of the subfloor, and the curb holds the water in. A curbless one has to give that height back, which means the deck under the shower drops by around two inches so the finished tile lands level with the floor outside it.
Sistering and Notching
Joists can be notched only within strict limits and never in the middle third of a span. The usual answer is to sister a member alongside and hang a lowered section from it, or to frame a shallow dropped platform between joists running the right way. This is a structural decision, and on a large opening it belongs on a drawing.
When the Framing Says No
On a concrete slab the deck cannot drop, so the whole bathroom floor is built up instead and the shower stays at slab level. That works and it moves the height difference to the door of the room. The other route is a low threshold of half an inch with a bevel, which is not curbless but reads and behaves almost the same.
Containment Without a Curb
Water stays in through slope and distance rather than through a barrier. That means a longer wet zone, a drain positioned to catch flow before it reaches the opening, and often a linear drain set at the entry itself. Waterproofing has to extend well past the shower opening onto the main floor, usually by at least a couple of feet.
Get the Sequence Right
Framing, then the recess, then the drain body set to the finished height, then the membrane, then a flood test, then tile. Deciding on a curbless entry after the floor is framed means paying to reframe it, which is why this is the first question asked about a shower rather than a detail chosen at the tile stage.