What type of concrete support is typically found above a fireplace opening?

The type of concrete support typically found above a fireplace opening is a lintel. A lintel is a horizontal structural element that spans the opening of a fireplace, providing support for the weight of the masonry or structure above it. It is essential for transferring loads from above down to the sides of the opening, ensuring the stability of the fireplace and surrounding wall.

In the context of a fireplace, the lintel supports not just the bricks or stone that form the chimney but also any other loads that may be present, such as the roof structure or upper floors. Proper installation of a lintel is crucial to avoid cracking or structural failure in the wall above the fireplace.

Column, foundation, and retaining wall do not serve the same function in this specific scenario. A column typically supports vertical loads from above, while a foundation is the base that supports the entire structure at ground level. A retaining wall is designed to hold back soil or other materials and is not relevant to the direct support of a fireplace opening. Thus, the most appropriate choice for the support found above a fireplace is indeed the lintel.