System and method for improved portland cement basecoat plasters

A method of using a lightweight plaster, the method comprising:

• a. performing a first step of making a lightweight plaster by mixing together in a mixer a first aggregate constituting between about 40 and 70% by weight of the plaster product and a binder constituting between about 20 and 40% by weight of the plaster product, and adding to the mixer a synthetic substitute aggregate occupying a same volume as the first aggregate plus or minus 10%;
• b. performing a second step of making a lightweight plaster by mixing together in a mixer a product of step (a) with water;
• c. applying the lightweight plaster as a coating to a vertical wall including a lath, lattice, or other substrate, to a thickness of about ⅜″ to ⅞″, such that the lightweight plaster acts as a base coat to plumb the vertical wall and to create a base to receive a finish coat application, the finish coat application being a stucco or acrylic synthetic finish or finish coat, such that only one lightweight plaster coating is required rather than two or more;
• and
• d. applying the finish coat application onto the lightweight plaster coating,
• e. such that a lightweight plaster coating is made and used to allow an end user to apply a plaster coating that is less in weight than prior plaster coatings while realizing no loss of yield per bag, and in which a lightweight plaster coating is achieved that provides greater insulative properties as compared to traditional base coats.