Gypsum underlayments can be placed at various compressive strengths, depending on the requirements of each job. These strengths range from 1,200 to 5,500 psi.
Why, and where, is poured gypsum underlayment used? It's popular for leveling condominium and apartment floors, particularly in fast-track construction projects where pre-formed concrete planks are used in the structure. Pre-formed planks require complete leveling and surfacing before any floor coverings may be installed.