Plane projection problem (the element is more higher than the control)

Question

I have a Grid witch contains a User Control. I want to make a flip effect and i'm applying a projection to the grid. The projection is rotating from Y axis from 0 to 180 degree. The problem is that during the animation the projection is increasing the height of my grid and the user control causing them to go out of the current page. If i scale the grid the animation don`t look well. If anyone could tell me how to resolve this i would be grateful.

Thanks.