Use your spirit level across multiple axes of the subfloor. If the floor slants significantly, plan to use a self-leveling underlayment compound or build a reinforced mortar bed to support the tub’s weight.

What ? (e.g., concrete slab or plywood joists)

Apply a bead of silicone sealant around the back of the overflow insert and press it firmly into the opening.

It is vastly easier to install the waste and overflow plumbing while the tub is out of the alcove.

– Used to build structural wall ledgers and supportive basin framing.