An earthen floor, also called an adobe floor, is a floor made of dirt, raw earth, or other unworked ground materials. It is usually constructed, in modern times, with a mixture of sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, finely chopped straw

Straw

Straw is an agricultural by-product, the dry stalks of cereal plants, after the grain and chaff have been removed. Straw makes up about half of the yield of cereal crops such as barley, oats, rice, rye and wheat. It has many uses, including fuel, livestock bedding and fodder, thatching and...

 and clay

Clay

Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

, mixed to a thickened consistency and spread with a trowel on a sub-surface such as concrete

Concrete

Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...

. Once dry, it is then usually saturated with several treatments of a drying oil

Drying oil

A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air. The oil hardens through a chemical reaction in which the components crosslink by the action of oxygen . Drying oils are a key component of oil paint and some varnishes...

.

Benefits

1. Variety of colors, textures, and materials
2. Can be installed over nearly any subflooring
3. Integrates well with in-floor radiant heat tubing
4. One of the cheapest flooring methods, green
   Environmentalism
   Environmentalism is a broad philosophy, ideology and social movement regarding concerns for environmental conservation and improvement of the health of the environment, particularly as the measure for this health seeks to incorporate the concerns of non-human elements...
   
    or otherwise.

History

Earthen floors were predominant in most houses until the mid 14th century in Europe, and persist to this day in many parts of the world. In medieval times, almost all peasant housing had earthen floors, usually of hardpacked dirt topped off with a thin layer of straw for warmth and comfort.
Soil in the southwestern parts of the US contain nearly a perfectly mixed ratio of adobe.

In China, most cottages and smaller houses also had earthen floors, made of rammed earth

Rammed earth

Rammed earth, also known as taipa , tapial , and pisé , is a technique for building walls using the raw materials of earth, chalk, lime and gravel. It is an ancient building method that has seen a revival in recent years as people seek more sustainable building materials and natural building methods...

 and sealed with raw linseed.

Earthen floors were discovered in ancient Greece, and in many other early developing civilizations.

Construction

In modern times, most earthen floors are often laid over the top of a subfloor of tamped gravel and then a mixture of clay, sand and fiber are mixed and leveled onto the tamped subfloor. These layers can be 1/8 to 1/4 of an inch thick. The thinner layers will dry faster but require a better subfloor for strength or more layers. Earthen floors can be laid over the top of previously installed wood floors but weight can become an issue.

Finishing

A drying oil like Linseed oil

Linseed oil

Linseed oil, also known as flaxseed oil, is a clear to yellowish oil obtained from the dried ripe seeds of the flax plant . The oil is obtained by cold pressing, sometimes followed by solvent extraction...

 is usually used to seal the floor and protect it from wear and tear. A final coat of perilla oil

Perilla oil

Perilla oil is obtained from the seeds of herbs of the genus Perilla, usually from the species Perilla frutescens. The seeds contain 35 to 45 percent oil which is obtained by pressing. Perilla oil is used along with synthetic resins in the production of varnishes...

 and a wax sealing finish are also used on high traffic flooring areas.

External links

• http://www.dancingrabbit.org/newsletter/Newsletter0701-floors.php (6 parts sand, 2 parts clay, 1 part finely chopped straw)
• http://www.housealive.org/newsletter-archive/earthen-floors.html (5 in road base + 1 in [70% sand, 30% clay and about 10% straw])
• Gelles, David, "Down and Dirty", The New York Times
  The New York Times
  The New York Times is an American daily newspaper founded and continuously published in New York City since 1851. The New York Times has won 106 Pulitzer Prizes, the most of any news organization...
  
  , February 8, 2007
• http://www.LanderLand.com (step by step how to)