What barrier must be placed between concrete form and base plate?

The correct choice of a sill gasket as the barrier between the concrete form and the base plate is essential for a few reasons. A sill gasket serves as a waterproof and air-tight barrier that prevents moisture from the concrete slab from migrating into the base plate material. This is particularly important as moisture can lead to problems such as rot, mold growth, or deterioration of both the structure and the base plate over time.

Moreover, the use of a sill gasket also helps in preventing thermal bridging, which occurs when heat flows through conductive materials. This can enhance the energy efficiency of the building by reducing heat loss in colder seasons. Additionally, sill gaskets can provide an added level of cushioning, which can help in adapting to slight irregularities in the surface of the concrete, ensuring a more secure and stable anchor for the structure being built.

Other materials like plastic sheeting or insulating foam do not provide the same level of connection and sealing that a sill gasket does. While they might offer some level of insulation or moisture barrier on their own, they do not replace the specific function that a sill gasket fulfills in a construction context.