Leveler for Balcony

[g8rdan23]

I am working on a balcony remodeling/repair on a residential condo. The existing concrete balcony does not provide any slope, so needless to say there is a problem with ponding water. Another problem is that the interior concrete surface is only ½” higher than the balcony, in an area where wind blown rain is normal, so we are building up a 4 ½” curb and providing a sloped surface at ¼” : 12”. The leveler will have a sonoguard water proofing membrane over it and 3/8” ceramic tile thin set on top of that. I was wondering if anyone could recommend a high strength product that will be used to create the slope…

Thanks