headers for a window in a block wall
 

I want to cut a whole on the exterior of the house and place a window I know what tools I have to use and have a plan to cut it but I dont know if I have to use a header for the window or not and if I do how and what do I make it out of?

The main supporting member in block or brick is usually a steel angle or "T" beam, 3/8-1/2 thick. Sometimes a prestressed concrete beam is used.