What is sheathing used for in concrete work?

Sheathing in concrete work primarily serves the purpose of holding and forming concrete. This involves the use of materials that create a mold or framework into which the concrete is poured. Sheathing materials, such as plywood or boards, ensure that the concrete maintains its desired shape and alignment during the curing process.

When concrete is poured, it has a very fluid consistency. Without sheathing, the concrete would not be able to maintain its form and could spread unevenly, leading to structural issues after it hardens. By effectively containing the concrete, sheathing plays a crucial role in achieving the correct dimensions and structural integrity of the final product.

While sheathing may provide some degree of insulation or affect other properties, its primary function in this context is related to shaping and containing the concrete mix until it solidifies. This makes option B the correct choice for the question regarding the use of sheathing in concrete work.