Plaster

PLASTER

Exterior plaster is almost always necessary on pressed block buildings. If the blocks are all earth, a protective covering is critical. Traditional three-coat stucco is the most common, utilizing 20-gauge chicken wire or 17-gauge self-furring stucco wire. The former is common, the latter - superior. The wire is covered with a scratch coat, a second (brown) coat, and a color coat of cement stucco. In cold climates, a layer of rigid insulation can be placed between the blocks and the stucco.

There is debate in the earth-building industry regarding a vapor barrier between the blocks and the stucco. Purists feel the vapor barrier will prevent the wall from "breathing" while others think that protecting the wall from water is the foremost consideration. A single-story building with adequate roof overhangs and thickened wainscoting is another solution. Other finish coats include synthetic (acrylic) stucco paint. If the blocks are, in fact, completely stabilized (waterproofed), it is possible to leave them exposed.

Interior earth plasters are a desirable finish because they are inexpensive, non-toxic, aesthetically pleasing, breathable and require no wire. There are many formulas for earth plaster, but the basic ingredients are typically clayey earth or sand. Other components can be lime, Portland cement, straw, cactus juice, ox blood, wheat paste, and a host of other possibilities limited only by the imagination.

There are a variety of adobe sealers available, both manufactured and natural.

Earth Block, Inc.

P.O. Box 3605
Pagosa Springs, CO 81147
Jim or Nora Hallock
Phone: 970-883-2456
Email: earthblock@juno.com