Anyone ever used a cinder block heater for brooder?

[smileygreen64]

I am wanting to transition to brooding outside instead of indoors. I plan on making it basically the same as a normal coop and run, with a enclosed sheltered spot and a large run. I know some people use cinder blocks with light bulbs inside to keep water from freezing . I was thinking the same concept would work for a brooder heater. My idea was getting some cinder blocks and some concrete bricks and stepping stones like you would have around a garden and building a structure with different heights so the chicks could move under them depending on the outside temperature. Cinder blocks would be the back of the structure with heat lamps in the holes. Then the entire thing would become a big heat sink once it had time to heat up. I would have to play with it a bit to see what kind of temperatures I can generate and how many bulbs and what kind of wattage I would need.

Anyone tried something similar or have and ideas or thoughts about it? I would appreciate any advice I could get.