Problem in adding elements to grid layout on Runtime.

I'm working on grid layout with content size fitter.
When I add button to grid it expand from both sides.
I want to expand the container to Only down side.

Here are screen shorts

It's the screen without play nothing on screen.



After play I'm getting this the middle part of container is visible not top said
I have to scroll to top for view




I want like this top part of container should be visible


So plz
Can any one tell me how to do it