El tapial transpira. Como el adobe, es higroscópico y tiene capacidad de difusión; también posee buena capacidad para almacenar frío o calor y tiene una emisión radiactiva muy baja. No es buen aislante, pero su grosor le proporciona una gran inercia térmica.

Es semejante al adobe "Adobe (construcción)"), en cuanto a la composición del material: tierra con algún aditivo —como paja o crin de caballo— para estabilizarlo, o pequeñas piedras para conseguir un resultado más resistente. Pero se distingue por el modo de hacer la fábrica. Los muros se levantan por tongadas de tierra húmeda entre unos maderos o tablas que forman un encofrado, al modo del hormigón en masa, apisonando cada tongada con un pisón.

No vale cualquier tipo de tierra para construir tapiales y, para mejorarlas generalmente se le añade áridos para aumentar la maleabilidad de la tierra y cal para añadirle propiedades ligeramente hidrófugas y mejorar la resistencia de los muros (tapia real). Hay que hacer también análisis del suelo que se va a utilizar, y es conveniente definir las proporciones de arena, arcilla y la cantidad de sílice que hay es este último elemento.

El tapial tiene una densidad de entre 1800 y 2100 kg/m³,[5]​ y una resistencia a compresión en torno a 1500 kPa (≈15 kg/cm²),[5]​ si bien esta resistencia depende mucho del tipo de tapial y su composición, pudiendo existir oscilaciones normalmente no superiores al 30 %. Su estabilidad dimensional es muy buena (0,012 mm/m °C),[5]​ y también sus propiedades como aislamiento acústico: un muro de 40 cm tiene una atenuación acústica de 56 dB[5]​. No es buen aislante térmico ya que la arcilla seca y compacta con la que se ejecuta tiene una conductividad térmica (λ) de 1,50 W/m·K,[6]​ lo que para espesores ordinarios de 50 cm supone una resistencia térmica (R) de 0,33 m²·K/W y una transmitancia térmica (U) de 3,00 W/m²·K, niveles de aislamiento térmico que se consiguen con una pared de ladrillo hueco de sólo 12 centímetros de grosor (1/2 pie), considerando para este λ=0,32 W/m·K.[6]​ Su calor específico (c) de entre 1670 y 2500 J/kg·K[6]​ y los notables espesores de las paredes, proporciona sin embargo una gran inercia térmica, lo que se traduce en que las construcciones mantienen en el interior una temperatura constante, ajustada a la media diaria de la temperatura exterior. Por esta razón, en climas continentales donde en verano los días son calurosos y las noches frescas, el interior se mantiene fresco. Sin embargo en invierno, en esos mismos climas, las construcciones de tapial son frías.

El tapial resiste muy mal la tracción, por lo que no admite cargas horizontales y es frecuente que se fisure con el tiempo. Asimismo es muy sensible a la erosión y a los agentes atmosféricos, exigiendo un mantenimiento cuidadoso de sus paramentos exteriores, que en España normalmente se revestían con mortero de cal o bastardo y se pintaban con lechada de cal. Por esta razón las construcciones se encalan periódicamente.

Internal reinforcements

A solution to stabilize compacted earth or rammed earth walls against the horizontal impacts of the earthquake is to use vertical elements of wood or bamboo within the wall, anchored to the foundation and fixed to the chains. Horizontal reinforcement elements are ineffective and can even be dangerous, because the earth cannot be compacted well beneath them and since the reinforcement element does not have an anchor with the earth, the section is weakened at these points and horizontal breaks may appear during the earthquake.

A system of rammed earth panels reinforced with bamboo was developed in 1978 as part of a research project at the Research Institute of Experimental Constructions (FEB) of the University of Kasse, and was successfully implemented in Guatemala with the University of Francisco Marroquin (UFM) and the Center for Appropriate Technology (CEMAT). In this project, elements 80 cm long and one story high were built from bamboo-reinforced rammed earth using a T-shaped metal formwork 80 cm long, 40 cm high and 14 to 30 cm thick. The stability of the elements was obtained with 4 bamboo rods of 2 to 3 cm thickness and T section. These elements were fixed at the base to a bamboo chain within a stone masonry plinth (cyclopean concrete) and at the top to a rectangular bamboo chain.

In 1998, the Experimental Construction Research Institute (FEB) and scientists from the University of Santiago de Chile developed another research project for an anti-seismic house made of reinforced rammed earth. The house was built in 2001 and has 55 m² of useful area. The design is governed by the idea of ​​separating the structure of the roof from that of the walls. The roof rests on columns independent of the solid rammed earth walls, causing both elements to move according to their own frequency in the event of an earthquake. The 40 cm rammed earth walls are L and U shaped. The right angle formed in these elements is replaced by a 45 degree angle to stiffen the corner. The rammed earth wall rests on a 50 cm thick cyclopean concrete foundation. The vertical reinforcements of the rammed earth are made up of coligüe canes (Chilean bamboo) 2.5 to 5 cm thick, fixed to the upper chain and anchored in the foundation. The chain is made up of two poplar logs in the shape of a ladder on the walls. The windows and doors are floor to ceiling and do not have solid wall segments over the openings. Likewise, the tympanum of the east and west facades was built with a structurally isolated partition to avoid the danger of solid materials falling during the earthquake.

The constructions carried out with this technique have bioclimatic properties since they have a "botijo" or "clay pot" effect, maintaining a relatively stable temperature inside throughout the year, both in summer with extreme heat and in winter with intense cold. In the tropics the average internal temperature of the year is about 25 °C, regardless of external temperatures.

Due to its extremely low energy content, it is currently seen as a construction technique that minimizes the environmental impact and greenhouse gas emissions: one of the main postulates of Sustainable Architecture.

To ensure the stability of the work once finished, it is advisable to use soil that has been removed for a year and exposed to the elements. Sometimes the clay mass can be lightened and strengthened by adding crushed straw, dried grasses or horsehair.

In many old buildings there are small, almost vertical holes in the rammed earth walls whose purpose is to evacuate water in case of rain or extreme humidity. For this reason it must be isolated from the ground; Very normally, a stone plinth or plinth must be made, often dry-rigged, to prevent it from absorbing moisture from the ground, especially when it rains.

The particularity of these mixed constructions is that as we move from the more humid areas, where this technique is used, to the more arid areas, an increasingly higher percentage of rammed earth is used in the construction of houses, to the detriment of other materials, due to the fact that it works better in dry climates and the ease of working and maintaining the rammed earth in these places.

On the contrary, in some places rammed earth is used only for the lower part of the house, due to the difficulty of raising the earth to a certain height, resolving the walls of the upper floors with adobe "Adobe (construction)").

Sometimes reeds or sticks arranged in a certain way are added inside the walls to increase resistance while maintaining the "elasticity" of the construction without adding weight.

Logically, it is an inappropriate construction technique for places with an extremely rainy climate due to the erosion that water can cause on the walls if they do not receive adequate maintenance. If an adequate foundation is made, with superior waterproofing, the possibility of humidity due to capillarity is minimal.

In any case, it is a form of construction that requires frequent but simple periodic maintenance, replacing the mud lining, since any type of rain, and even more so in so-called dry climates, in which when it rains it can be very strong, which erodes the exterior part of the wall. A very impermeable cement mortar lining should never be made, which would degrade the wall due to lack of ventilation and moisture evaporation.

With tapial all types of structures were built such as houses, haystacks, walls for animal pens, even walls for fortresses.

• - Adobe.

• - Bahareque.

• - Brencas.

• - Quincha.

• - Fujian Tulou, Chinese rammed earth construction from southwestern Fujian.

• - Thermal inertia.

• - Thermal mass.

• - Cob (construction) "Cob (construction)").

• - Cement floor.

• - Selective ventilation.

• - Bioclimatic architecture.

• - Sustainable architecture.

• - Basilio Pavón Maldonado, "WALLS OF TAPIAL, MASONRY, SHELL AND BRICK IN WESTERN ISLAM (The architectural remains of the Reconquista. Inventory and classifications).[2].

• - Cortés, A. (1996) "Tests for the Use of Raw Land in construction with the use of Solar Energy in the Pampas Zone." Renewable Energy and Environment Magazine - ASADES. [3].

• - Cortés, A. (1996) "Possibilities of Raw Earth in construction in the Pampas Zone. Use of Solar Energy." Minutes of the 19th Work Meeting of the Argentine Solar Energy Association, T.I., 02.1, Mar del Plata.

• - CYTED - Ibero-American Science and Technology for Development Program. (1995) "Recommendations for the development of technical standards for adobe, rammed earth, brick and soil-cement blocks construction." Habiterra - Graphic Editions E.G. - La Paz (Bolivia) (1st ed.).

• - Di Bernardo, E. and Cortés, A. "Construction of a passive solar building in soil-cement." [4].

• - The cement floor [5].

• - Self-sufficiency digital magazine. Various articles on earth constructions. [6].

• - Soils stabilized with cement. FOM Order 891/2004 (Spain). [7] Archived March 20, 2007 at the Wayback Machine.

• - Viñuales Graciela (Compiler). Celia M. Martins Neves, Mario O. Flores, L. Silvio Rios. (1994). "Earth architectures in Latin America." Science and Technology for Development Program. Habiterra - Impressions South America - Buenos Aires.

• - Viñuales, Graciela María (1981). "Restoration of earth architectures".. San Miguel de Tucumán, Argentine Research Institute for the History of Architecture and Urbanism, 1981.

• - Constructed Land / Terre Construite: association for the study of land as a construction material and cooperation between France and Argentina [8].

• - Minke, Gernot (2005). "Construction Manual for anti-seismic earth homes." Kassel, Germany. Research Institute for Experimental Constructions (FEB) University of Kassel. (2005).

• - Wikimedia Commons hosts a multimedia category on Tapial.

• - Terre Construite/Tierra Construida: site of the cooperation and training association between France and Argentina on earth as a construction material.

• - Manual for the rehabilitation of homes built in adobe and rammed earth, Colombia 2005.

• - construTIERRA Network: Research network with land in Spain.

• - The restoration of the rammed earth in the Iberian Peninsula: criteria, techniques, results and perspectives (Review).

El tapial transpira. Como el adobe, es higroscópico y tiene capacidad de difusión; también posee buena capacidad para almacenar frío o calor y tiene una emisión radiactiva muy baja. No es buen aislante, pero su grosor le proporciona una gran inercia térmica.

Es semejante al adobe "Adobe (construcción)"), en cuanto a la composición del material: tierra con algún aditivo —como paja o crin de caballo— para estabilizarlo, o pequeñas piedras para conseguir un resultado más resistente. Pero se distingue por el modo de hacer la fábrica. Los muros se levantan por tongadas de tierra húmeda entre unos maderos o tablas que forman un encofrado, al modo del hormigón en masa, apisonando cada tongada con un pisón.

No vale cualquier tipo de tierra para construir tapiales y, para mejorarlas generalmente se le añade áridos para aumentar la maleabilidad de la tierra y cal para añadirle propiedades ligeramente hidrófugas y mejorar la resistencia de los muros (tapia real). Hay que hacer también análisis del suelo que se va a utilizar, y es conveniente definir las proporciones de arena, arcilla y la cantidad de sílice que hay es este último elemento.

El tapial tiene una densidad de entre 1800 y 2100 kg/m³,[5]​ y una resistencia a compresión en torno a 1500 kPa (≈15 kg/cm²),[5]​ si bien esta resistencia depende mucho del tipo de tapial y su composición, pudiendo existir oscilaciones normalmente no superiores al 30 %. Su estabilidad dimensional es muy buena (0,012 mm/m °C),[5]​ y también sus propiedades como aislamiento acústico: un muro de 40 cm tiene una atenuación acústica de 56 dB[5]​. No es buen aislante térmico ya que la arcilla seca y compacta con la que se ejecuta tiene una conductividad térmica (λ) de 1,50 W/m·K,[6]​ lo que para espesores ordinarios de 50 cm supone una resistencia térmica (R) de 0,33 m²·K/W y una transmitancia térmica (U) de 3,00 W/m²·K, niveles de aislamiento térmico que se consiguen con una pared de ladrillo hueco de sólo 12 centímetros de grosor (1/2 pie), considerando para este λ=0,32 W/m·K.[6]​ Su calor específico (c) de entre 1670 y 2500 J/kg·K[6]​ y los notables espesores de las paredes, proporciona sin embargo una gran inercia térmica, lo que se traduce en que las construcciones mantienen en el interior una temperatura constante, ajustada a la media diaria de la temperatura exterior. Por esta razón, en climas continentales donde en verano los días son calurosos y las noches frescas, el interior se mantiene fresco. Sin embargo en invierno, en esos mismos climas, las construcciones de tapial son frías.

El tapial resiste muy mal la tracción, por lo que no admite cargas horizontales y es frecuente que se fisure con el tiempo. Asimismo es muy sensible a la erosión y a los agentes atmosféricos, exigiendo un mantenimiento cuidadoso de sus paramentos exteriores, que en España normalmente se revestían con mortero de cal o bastardo y se pintaban con lechada de cal. Por esta razón las construcciones se encalan periódicamente.

Internal reinforcements

A solution to stabilize compacted earth or rammed earth walls against the horizontal impacts of the earthquake is to use vertical elements of wood or bamboo within the wall, anchored to the foundation and fixed to the chains. Horizontal reinforcement elements are ineffective and can even be dangerous, because the earth cannot be compacted well beneath them and since the reinforcement element does not have an anchor with the earth, the section is weakened at these points and horizontal breaks may appear during the earthquake.

A system of rammed earth panels reinforced with bamboo was developed in 1978 as part of a research project at the Research Institute of Experimental Constructions (FEB) of the University of Kasse, and was successfully implemented in Guatemala with the University of Francisco Marroquin (UFM) and the Center for Appropriate Technology (CEMAT). In this project, elements 80 cm long and one story high were built from bamboo-reinforced rammed earth using a T-shaped metal formwork 80 cm long, 40 cm high and 14 to 30 cm thick. The stability of the elements was obtained with 4 bamboo rods of 2 to 3 cm thickness and T section. These elements were fixed at the base to a bamboo chain within a stone masonry plinth (cyclopean concrete) and at the top to a rectangular bamboo chain.

In 1998, the Experimental Construction Research Institute (FEB) and scientists from the University of Santiago de Chile developed another research project for an anti-seismic house made of reinforced rammed earth. The house was built in 2001 and has 55 m² of useful area. The design is governed by the idea of ​​separating the structure of the roof from that of the walls. The roof rests on columns independent of the solid rammed earth walls, causing both elements to move according to their own frequency in the event of an earthquake. The 40 cm rammed earth walls are L and U shaped. The right angle formed in these elements is replaced by a 45 degree angle to stiffen the corner. The rammed earth wall rests on a 50 cm thick cyclopean concrete foundation. The vertical reinforcements of the rammed earth are made up of coligüe canes (Chilean bamboo) 2.5 to 5 cm thick, fixed to the upper chain and anchored in the foundation. The chain is made up of two poplar logs in the shape of a ladder on the walls. The windows and doors are floor to ceiling and do not have solid wall segments over the openings. Likewise, the tympanum of the east and west facades was built with a structurally isolated partition to avoid the danger of solid materials falling during the earthquake.

The constructions carried out with this technique have bioclimatic properties since they have a "botijo" or "clay pot" effect, maintaining a relatively stable temperature inside throughout the year, both in summer with extreme heat and in winter with intense cold. In the tropics the average internal temperature of the year is about 25 °C, regardless of external temperatures.

Due to its extremely low energy content, it is currently seen as a construction technique that minimizes the environmental impact and greenhouse gas emissions: one of the main postulates of Sustainable Architecture.

To ensure the stability of the work once finished, it is advisable to use soil that has been removed for a year and exposed to the elements. Sometimes the clay mass can be lightened and strengthened by adding crushed straw, dried grasses or horsehair.

In many old buildings there are small, almost vertical holes in the rammed earth walls whose purpose is to evacuate water in case of rain or extreme humidity. For this reason it must be isolated from the ground; Very normally, a stone plinth or plinth must be made, often dry-rigged, to prevent it from absorbing moisture from the ground, especially when it rains.

The particularity of these mixed constructions is that as we move from the more humid areas, where this technique is used, to the more arid areas, an increasingly higher percentage of rammed earth is used in the construction of houses, to the detriment of other materials, due to the fact that it works better in dry climates and the ease of working and maintaining the rammed earth in these places.

On the contrary, in some places rammed earth is used only for the lower part of the house, due to the difficulty of raising the earth to a certain height, resolving the walls of the upper floors with adobe "Adobe (construction)").

Sometimes reeds or sticks arranged in a certain way are added inside the walls to increase resistance while maintaining the "elasticity" of the construction without adding weight.

Logically, it is an inappropriate construction technique for places with an extremely rainy climate due to the erosion that water can cause on the walls if they do not receive adequate maintenance. If an adequate foundation is made, with superior waterproofing, the possibility of humidity due to capillarity is minimal.

In any case, it is a form of construction that requires frequent but simple periodic maintenance, replacing the mud lining, since any type of rain, and even more so in so-called dry climates, in which when it rains it can be very strong, which erodes the exterior part of the wall. A very impermeable cement mortar lining should never be made, which would degrade the wall due to lack of ventilation and moisture evaporation.

With tapial all types of structures were built such as houses, haystacks, walls for animal pens, even walls for fortresses.

• - Adobe.

• - Bahareque.

• - Brencas.

• - Quincha.

• - Fujian Tulou, Chinese rammed earth construction from southwestern Fujian.

• - Thermal inertia.

• - Thermal mass.

• - Cob (construction) "Cob (construction)").

• - Cement floor.

• - Selective ventilation.

• - Bioclimatic architecture.

• - Sustainable architecture.

• - Basilio Pavón Maldonado, "WALLS OF TAPIAL, MASONRY, SHELL AND BRICK IN WESTERN ISLAM (The architectural remains of the Reconquista. Inventory and classifications).[2].

• - Cortés, A. (1996) "Tests for the Use of Raw Land in construction with the use of Solar Energy in the Pampas Zone." Renewable Energy and Environment Magazine - ASADES. [3].

• - Cortés, A. (1996) "Possibilities of Raw Earth in construction in the Pampas Zone. Use of Solar Energy." Minutes of the 19th Work Meeting of the Argentine Solar Energy Association, T.I., 02.1, Mar del Plata.

• - CYTED - Ibero-American Science and Technology for Development Program. (1995) "Recommendations for the development of technical standards for adobe, rammed earth, brick and soil-cement blocks construction." Habiterra - Graphic Editions E.G. - La Paz (Bolivia) (1st ed.).

• - Di Bernardo, E. and Cortés, A. "Construction of a passive solar building in soil-cement." [4].

• - The cement floor [5].

• - Self-sufficiency digital magazine. Various articles on earth constructions. [6].

• - Soils stabilized with cement. FOM Order 891/2004 (Spain). [7] Archived March 20, 2007 at the Wayback Machine.

• - Viñuales Graciela (Compiler). Celia M. Martins Neves, Mario O. Flores, L. Silvio Rios. (1994). "Earth architectures in Latin America." Science and Technology for Development Program. Habiterra - Impressions South America - Buenos Aires.

• - Viñuales, Graciela María (1981). "Restoration of earth architectures".. San Miguel de Tucumán, Argentine Research Institute for the History of Architecture and Urbanism, 1981.

• - Constructed Land / Terre Construite: association for the study of land as a construction material and cooperation between France and Argentina [8].

• - Minke, Gernot (2005). "Construction Manual for anti-seismic earth homes." Kassel, Germany. Research Institute for Experimental Constructions (FEB) University of Kassel. (2005).

• - Wikimedia Commons hosts a multimedia category on Tapial.

• - Terre Construite/Tierra Construida: site of the cooperation and training association between France and Argentina on earth as a construction material.

• - Manual for the rehabilitation of homes built in adobe and rammed earth, Colombia 2005.

• - construTIERRA Network: Research network with land in Spain.

• - The restoration of the rammed earth in the Iberian Peninsula: criteria, techniques, results and perspectives (Review).