Should you a use self leveling product over the slope towards a drain in the concrete floor in basement bathroom? We are wanting to install luxury vinyl plank in the bathroom and most sites say to have a perfectly level floor for it. The problem is, the concrete was purposefully made to have a slope towards the drain (built in 2015). Should we level it first or is that a mistake? I’d say the lowest spot is about 1” difference. The bathtub was installed with shims to compensate. I don’t want it to be obvious that the flooring isn’t level. Can someone please help me on what I should do for this?
The problem isn't level, it's flat. Your flooring simply won't accommodate the compound bends that a dish in the concrete presents. You'll get open gaps at the joints and the tile may lift, creating voids underneath.
You'll want to investigate whether you can heat and bend your flooring to make it conform to the shape needed, or whether you can make extra cuts to allow it to fit the floor.
If you decide to level the floor, cut a disk of material the same thickness as the repair and slightly larger than the drain. Tape it down securely to seal the opening. Make your patch, then install a cleanout cover over the drain. You could also extend the drain with the right parts.