At many construction sites, I've seen where the concrete guys have layed 1 course of L-shaped blocks around the perimeter of a foundation. These L-shaped blocks act as a form for the concrete slab that is poured inside the perimeter. Can anyone tell me what the proper name of these L-shaped blocks is, and where I can purchase them??
I think what you are looking for is a hollow header or solid header block depending on whether or not it is cored. A masonry supply house or a local building supply house. I've never seen them at a big box store.