A Fine Finish: Natural Wall Finishes, Nontoxic Paints and Clay Plasters

Enlarge Image Image Gallery American Clay offers a wide variety of color pigment options. Photo By Bo Parker

A new wall finish can transform your home. Finishes protect walls from the elements and from daily wear, and they play an important role in regulating indoor temperature and humidity. Natural finishes, which undergo minimal processing and are generally nontoxic, can be made from clay, lime, chalk, casein, rock dusts, earth pigments, and natural plant extracts such as oils and waxes. These naturally beautiful materials bathe walls in color and texture while balancing relative humidity, creating a more comfortable indoor environment.

Natural finishes are essential for buildings made of straw bales, cob and non-stabilized adobe because these materials must “breathe” to remain healthy. However, their use is hardly limited to those types of homes. They’re compatible with all wall types, though some walls require a nontoxic primer.

• Don’t use conventional paints, which often are petroleum-based and contain poisonous chemicals and volatile organic compounds (VOCs).

• Do consider making your own clay plaster using local soils.

DIY or buy?

You can buy pre-manufactured natural finishes such as clay-based paints and plasters at specialty building supply stores. You can also make handmade finishes such as clay plaster and limewash using simple ingredients. Homemade finishes are less predictable than those out of a can or a packet, so it’s essential to assess performance, texture and appearance by testing wall patches before application.

Homemade clay plaster or paint