2.2
Muros de mampostería con cámara
Los muros de mampostería con cámara presentan un espacio hueco entre las capas exteriores e interiores, conectados únicamente por tirantes metálicos r…
Un muro de cavidad de mampostería consta de dos wits separados por un espacio hueco. Las cuerdas exterior e interior están conectadas mediante bridas de mampostería resistentes a la corrosión para la estabilidad estructural.
Cuando el agua penetra en el exterior de la cavidad, entra en la cavidad y es recogida por una delgada membrana impermeable llamada tapajuntas, que se instala en la parte inferior de la cavidad y se drena a través de orificios de drenaje.
Además, el material antihumedad aplicado en el lado de la cavidad del interior protegerá los interiores de la penetración de agua y también servirá como barrera de aire.
Durante la construcción, los escombros, como los excrementos de mortero, pueden bloquear el sistema de drenaje, por lo que es crucial mantener la cavidad limpia. El uso de material de deflexión de mortero puede ayudar a evitar el bloqueo del drenaje en la cavidad.
La cavidad facilita el aislamiento acústico y la colocación de conductos para la distribución de servicios públicos dentro de un edificio.
Además, la inserción de tableros aislantes de plástico de espuma rígida en la cavidad puede proporcionar aislamiento térmico.
Las paredes de la cavidad pueden ser portantes o no portantes. En los muros de cavidades portantes, el wythe interior soporta cargas estructurales, mientras que el wythe exterior no estructural es una chapa.
En los muros no portantes, el wythe interior proporciona soporte lateral al wythe exterior a través de los tirantes de mampostería.
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Q1: What are the two main components of a masonry cavity wall?
A masonry cavity wall consists of two wythes—an outer wythe and an inner wythe—separated by a hollow space. These wythes are connected using corrosion-resistant masonry ties that provide structural stability. The cavity between them serves multiple functions, including moisture management, insulation placement, and utility distribution.
Q2: How does water drainage work in a cavity wall system?
When water penetrates the outer wythe, it enters the cavity and is collected by flashing, an impervious membrane installed at the cavity's bottom. The water then drains out through weep holes. Dampproofing material applied to the cavity side of the inner wythe prevents water from reaching interior spaces and also functions as an air barrier, protecting the building from moisture damage.
Q3: Why is keeping the cavity clean during construction important?
Debris like mortar droppings can block the drainage system, preventing water from exiting through weep holes and compromising the wall's moisture protection. Using mortar deflection material or beveled bed joints helps prevent mortar from entering the cavity. Traditional practices involved placing steel ties to catch droppings, which are then removed, but modern deflection methods are more effective and easier to implement.
Q4: What are the differences between load-bearing and non-load-bearing cavity walls?
In load-bearing cavity walls, the inner wythe supports structural loads while the outer wythe functions as a nonstructural veneer. In non-load-bearing cavity walls, the inner wythe provides only lateral support to the outer wythe through masonry ties, supporting only its own weight. Both configurations use corrosion-resistant ties to maintain structural connection between the wythes.
Q5: How can cavity walls provide thermal insulation?
Rigid foam plastic insulating boards can be inserted within the cavity space to provide thermal insulation and mitigate heat transfer through the wall assembly. This placement leverages the existing hollow space without requiring additional structural modifications, making it an efficient method for improving the building's energy performance while maintaining the cavity's drainage and moisture management functions.
Q6: What additional functions does the cavity space serve beyond moisture control?
Beyond moisture management, the cavity facilitates sound insulation, reducing noise transmission through the wall. It also provides space for placing conduits and utilities for building distribution systems. The hollow space allows for flexible routing of electrical, plumbing, and mechanical systems without compromising the structural integrity of the masonry wythes.
Q7: How do masonry ties contribute to cavity wall performance?
Corrosion-resistant masonry ties connect the outer and inner wythes, providing essential structural stability and lateral support. In non-load-bearing walls, ties support the outer wythe's weight and resist lateral forces. Their corrosion resistance ensures long-term durability and prevents deterioration that could compromise the wall's structural integrity and the connection between wythes.