Man, what is it with all guys and the volume of the drums?!? Geez, instead of going out to Home Depot and trying to construct some shield (that wont work in a church anyway re: ceiling heights)......JUST TURN DOWN!!!
If its the drummers fault, ask him or her to play with brushes or hot rods.
if its anyone else's fault, turn the amp down. Twist. That's a lot easier and probably in the end going to be more musical than building a sound dam.
If the drummer is still too loud, or refuses to play with anything other than sticks - fire them.
ajc