Advantages of (AAC) Autoclaved Aerated Concrete

Energy Efficient:

High energy efficiency in a building is desirable for many reasons. By reducing heating and cooling requirements, lower operating costs and equipment sizes are achieved. Better temperature and humidity control will provide greater comfort for the building occupants. The reduced energy requirement of a building also helps conserve natural resources such as oil, coal, propane, natural gas, etc., thereby reducing emission of pollutants into the atmosphere. Both the reduction in energy usage and pollutants should be considered over the total useful life of the building.

It is widely recognized that AAC buildings are very energy efficient. This efficiency is due to a combination of high R-value, thermal mass and air-tightness.

A recent study in the U.S. shows that an 8” AAC wall performs much better than a conventional wood stud wall system. As with a concrete wall, the mass of an AAC wall stores thermal energy when the ambient temperature is higher than the wall temperature. That energy is released when the ambient temperature drops below the wall temperature. This moderating effect can result in significant savings, especially in climates where temperatures vary widely during a 24-hour period. And, in a typical wood frame house, exterior air moving through the wall can account for up to 30% of the heating or cooling costs.  An 8” AAC wall achieves an R-30 rating versus a 2x6 wood stud wall at R-19.

The manufacturing process creates millions of tiny air cells that provide excellent thermal resistance. This thermal resistance combined with the benefits of thermal mass inertia, whole wall coverage and low air infiltration eliminates the need for additional insulation.

Fire Resistant:

A danger of many conventional materials is that of toxic fumes produced when they burn. The same properties that make AAC thermally efficient also provide exceptional fire resistance characteristics. AAC is an inorganic material that does not burn. The melting point of AAC is over 2900~F (1600~C), more than twice the typical temperature in a building fire of 1200~F (650~C.) An 8” AAC exterior wall easily exceeds a four hour ASTM E-119 fire rating, while a typical AAC floor system or 4” interior wall easily exceeds a two hour rating.  An Autoclaved Aerated Concrete has the industry’s highest UL rating, as a construction material.

               
                This AAC house survived a devastating fire in California 
                              while neighboring homes were destroyed.

U.S. fire departments respond to an average of 396,000 house fires per year, accounting for 3,030 deaths, nearly one every two hours. Most were from toxic fumes generated from traditional materials burning, not flames. Since AAC is an inorganic material that does not burn, it does not release these toxic gases in the event of a fire.

Environmentally Friendly:

AAC is well known as an environmentally friendly construction material. The production of AAC requires only a fraction of the energy compared to other materials. The manufacturing process emits no pollutants and creates no by-products or toxic waste products.

AAC is manufactured from common and abundant natural raw materials. The finished product is up to five times the volume of the raw materials used, making it extremely resource-efficient and environmentally friendly. Manufacturing waste is recycled into the raw material mixing process. AAC is recyclable, inert, nontoxic. AAC is not a source of chemical off-gassing that can cause indoor air pollution and illnesses.

In the U.S., it is estimated that 80 to 90 percent of an average person's time is spent indoors; at home, work and in other buildings. A number of issues must be addressed concerning these buildings and their environmental friendliness. Indoor air quality, safety, comfort, energy consumption and waste, noise, and in general how "healthy" a building is, are some of the more important issues.

It is widely known that some of the poorest quality air we breathe is in our homes and the buildings we work in. Many materials used in construction contain toxic substances and off-gas. It is not unusual for construction materials to pollute indoor air with formaldehydes, benzene, arsenics, and other chemicals that are classified as hazardous to human health. Even fiberglass insulation, a commonly used material, is classified as a carcinogen by the U.S. Government. AAC is an inorganic material that contains no toxic substances. It does not slowly decompose and off-gas. Since AAC is both a structural and insulation material, it allows the elimination of other materials that can contribute to poor indoor air quality. With the mineral based plaster coatings commonly used on the interior of AAC, complete elimination of toxic materials from the walls is possible. 

Strong:

Dimensional accuracy and compressive strength allow AAC to be used in many load bearing applications, whether it is a large, small or tall job. Installed using thin bed mortar, the resulting wall functions as a monolithic structure.

Durable:

Durability, and its environmental impact, is an important factor when considering use of a building material. A structure that does not need major repairs and renovation every twenty years or so (as many wood products require) can save money, inconvenience, energy and other resources. This is of tremendous advantage to the building owner, creating a better investment and value up-front and long-term. AAC has proven to be a very durable material. There are numerous structures worldwide, many over 60 years old, in excellent condition. AAC will not rot, warp, rust, corrode, or otherwise decompose. AAC provides a very low maintenance building, saving considerable time and money in upkeep over the life of the building. Although damage to an AAC wall is unlikely, repair is simple using a AAC repair mortar.

The durability of finishes, both exterior and interior, plays an important role environmentally. With AAC, any number of interior and exterior coatings or applications are possible. More common coatings, such as a stucco type finish, along with interior plaster, aid in creating a more environmentally friendly structure. The stucco type finish used on AAC is very durable and requires little maintenance. These finishes can be integrally colored with mineral pigments, eliminating the need for frequent painting. Interior plaster applied to AAC is durable, yet easy to repair. Veneered plaster can be left unpainted, providing a pleasing appearance.

AAC will not rot, warp, rust, corrode, or otherwise decompose. Termites and other pests do not eat it. AAC will not burn. The millions of tiny cells in AAC cushion buildings from major force, preventing progressive collapse. AAC has withstood earthquakes in Japan, the frigid temperatures of northern Europe, the harsh salt air of the French Riviera, and the hillside fire-prone regions of Southern Europe.

Lightweight:

Weighing approximately 20% the weight of normal concrete. AAC provides significant benefits where weight is a concern in building design. AAC is ideal for renovations. The product provides beneficial installer safety and fatigue features.

Workable:

AAC can be easily cut and shaped using standard construction tools. Window trim and decorative features can easily be created on the job site. 

Dimensionally Accurate:

State-of-the-art cutting equipment produces blocks that are dimensionally accurate to within 1/8”, making AAC easy to install.

Low Maintenance:

AAC is an inorganic material impervious to rot, insects, and other pests. Since the walls are solid, it is not possible for insects to inhabit and breed in them as in most wall systems. Without concern of termites and other insects damaging or inhabiting the AAC portion of the structure, chemical treatments can be reduced or eliminated. This prevents the need of putting these chemicals into the ground, or the indoor air, with their associated environmental and health threats.

Buildings constructed over sixty years ago in many different climates have proven AAC to be one of the most durable building materials available. Recommended where termites are a concern.

Low Construction Costs:

In addition to these outstanding product features, independent studies has shown AAC to be a cost-effective alternative to existing building materials. The homeowner can get all the benefits of AAC without paying a high premium for the extra sound, fire and thermal insulation features.

Sound Absorbent:

A commonly overlooked environmental problem in residential construction is that of noise. The solid wall construction of a building made of AAC provides excellent sound abatement, greatly reducing outside environmental noise, providing a quieter, more comfortable interior for the occupants.

AAC's porous structure and high surface mass, coupled with its ability to dampen mechanical vibration energy, make for a building material that provides an outstanding defense against noise pollution.