Paneles aislantes are membrane walls used to prevent air from entering the panel which is made of a highly-porous material. Thermal resistance for paneles aislantes is less conventional but increasingly popular. However, there are serious downfalls to using this type of insulation. The panel has to maintain its vacuum over a long period of time, but air still gradually enters the panel as the pressure of the panel normalizes with its surrounding air and its resistance value deteriorates. Conventional insulation does not depend on the evacuation of the air for its thermal performance, which is why it is not susceptible to this form of deterioration.


In addition, thermal resistance type of insulation for paneles aislantes is provided by products that cannot be cut to fit as with conventional insulation because it would destroy the vacuum. Therefore, non-standard sizes must be custom made, which increases the costs that are already high enough. As a result, thermal resistance products for paneles aislantes are generally kept out of traditional housing situations. However, their low thermal conductivity makes them useful in situations in which strict insulation requirements or space constraints make traditional insulation useless or impractical.   


In the same category of household insulation products and methods is the fire cement — cemento refractario. It is a building material used to cover the exterior of a building in both commercial and domestic applications.

In appearance, cemento refractario consists of overlapping horizontal boards but it is also manufactured in a sheet form. Cemento refractario is a very heavy product but it is also fragile before installation, which is why it must be handled carefully in order to avoid chipping and breakage.


Cemento refractario can be painted before or after installation, but it is advisable to paint the whole wall after installation. Furthermore, users should only purchase products that have been tested by accredited laboratories which can guarantee that the cemento refractario is free from asbestos or other harmful materials such as inorganic fiber.

Nevertheless, regardless of its organic and safety quality, any type of cemento refractario is non combustible and can easily substitute traditional timber fascia and barge board materials. Therefore, cemento refractario is appropriate for use in heater construction. The main requirements of cemento refractario used in heater construction are the following: high density, large aggregate and high tolerance to thermal shock. 


There are several methods of applying el cemento refractario. It can be gunned, rammed or poured. Pouring is the easiest for the studio potter without elaborate equipment. Cemento refractario comes in a coarse aggregate form and is mixed with water. The more water used, the weaker el cemento refractario. The best results come from adding water until the aggregate almost loses suspension and starts to settle. It requires a couple of minutes to mix 50 pounds in a five gallon bucket with the aid of a mixer and an electric drill. Cemento refractario begins to harden in about 30 minutes so that entire sections must be mixed and cast in that period of time to be free of seams.  


If cemento refractario breaks down at some point in the future, the present lining can be taken out and another cast in its place. The only disadvantage to using cemento refractario is the extra time required to construct the forms. There are many types of cemento refractario available — ranging from 50% to 95% alumina. The higher the alumina, the higher the cost.   

Refractory company engineers are very helpful in calculating the amount of cemento refractario required per job and arch thickness. But, before calling a company for information, the exact dimensions of the proposed construction (including span of arch and arch rise) have to be known.



Learn more about paneles aislantes and find out more about cemento refractario.