Thank you in advance for any advice. I have read through other threads, picking up pieces of advice, but haven't seen anything that aligns with my project.
I am replacing a 30 x 60 tub with a tile shower. I plan to use a Proline drain by Quickdrain. Since this is an above floor waste line, their system utilizes flat and sloped polypropylene (http://quickdrainusa.com/info.php) honeycomb material as the base for the shower floor. This honeycomb material is thinset to the floor.
My subfloor is 3/4" plywood @ 24" o/c steel joists. There are some minor low and high spots. I would like to ensure a firm and flat floor. I could use some advice re: the correct materials and sequencing to accomplish a firm and flat floor.
My initial thought was to fill low spots with Henry 549, then glue and screw 3/4" plywood. However, based on what I have read it seems like there can be problems (break up) screwing through a floor patch compound (Henry did say I can if I drill pilot holes first, but I am hesitant). Am I using the right materials, but need different sequencing, or should I be using different materials (e.g., ditra, hardibacker, etc)?