Adhesive performance on exposed decks.

[jay]

when you say cast deck can you explain is it poured concrete 1 piece or made up of sections

 

[Geoff Hunt]

Its a pre cast plank (made up sections)

 

[jay]

So i take it has cracked on the sections or joins.These joins should of been carried through the tile surface (as a movement joint or expansion joint)
The other thing you may want to consider is most pre cast slabs are formed in boxing molds witch are coated in a release agent (to save the boxing) was the slabs cleaned before tiling started

hope this helps