Hello I'm a newbie here and desperately need some advise. I have an exterior patio plywood deck covered with Floor Tex. I had a 5 X 10 area that was replaced. I used MH ready patch for the edges, and knotholes, & screw heads. Sanded it smooth, painted it over with three coats of the Floor Tex....Well we had rain the other day and the repaired exterior area has cracked. I am in process of peeling it off. I need your expertise on what putty, paste or filler should be used that wont crack or shrink. I thank you in advance for your assistance.