Have you ever used this Custom Building Product
"Redgard" antifracture membrane? Does it work????
I always used Mapelastic and it works just fine but the price is really expensive. I saw Redgard at home depot and it cost around 30$ for 110 square feet of coverage and you set like Mapelastic, with the 3/16" notched trowel first and flat the ridges with the flat part.