Roof Insulation-- Using Umbrella effect

If we google the term ‘roof insulation’, we will find numerous products for insulation. But what we in hot regions fail to realize is that almost all such products, are designed to insulate against cold weather and not the hot weather. For insulating against cold, one needs padding but for insulating against heat, all one needs is to block the sunlight which is the only cause of heat transmission. In winters we buy a padded jacket but in summer; what we need is an umbrella to protect us from the sun which is the cause of heat. No rocket science or state of the art insulating material is required to block the sun. Unfortunately most home owners as well as building industry professionals in hot regions, fail to realize the fact.

Roofs are responsible for absorbing the bulk of heat in any building. Almost 80% of heat is conducted into the top floor of a building through the roof. The question is how to provide a shade to the roof? But before discussing this, we need to first go through the question that comes before which is; why to insulate at all?’.

WHY TO INSULATE

Insulation is required in both Air conditioned and ventilated environments. In case of air conditioned premises, insulation serves as an excellent energy saving measure. The temperature of a concrete roof exposed to sunlight gets several degrees higher than the normal atmospheric temperature and thus, act as a heating coil of a heater. The compressor of an air condition has to run almost continuously to cool down the temperature of the ceiling but this is a race which an air conditioner can hardly win as constant sunlight is a source of constant heat. Concrete roofs may take several hours to cool down even after the sun sets. This may cause huge losses in terms of energy resulting in enormous electricity bills. In air conditioned premises the cost of insulation is usually recovered within a year.

In non air-conditioned premises, insulation can bring down the temperature inside the premises to under body temperature (98.5 F) or (38 C) thus making living conditions comfortable. Please keep in mind that a single degree over body temperature makes the environment considerably uncomfortable. This is like a single degree fever can make you feel ill. You feel perfectly all right when the body temperature is 98.5 but when it reaches 99.5 you start to feel lethargic.

HOW TO BLOCK THE SUN AND PROVIDE SHADE TO ROOFS

As I said that no rocket science is required in insulating against heat and what is required is to block the sun-rays. In olden days when the homes were smaller and plots were bigger, people use to plant trees around to provide shade to the building areas. You may find such old homes today with old and tall trees surrounding the constructed area.

In present times the commercial buildings as well as residential ones are built on smaller plots of land with no room to plant trees around to provide an umbrella effect. Also that the height of buildings makes it impossible for trees to provide shelter.

In such cases a system is required to provide shade. This can be easily achieved by something called Raised Flooring. Raised flooring was actually invented to conceal wires and cable network in office floors which can be easily made to run under it. But it can be used for another function; which is to block the sun over roofs. How it can be installed is visible in the above picture. Just make sure that the tile material is UV resistant and can survive the sun.

During my waterproofing career, I noticed that people installed some fancy insulating systems over the roofs that were not only costly but also created problems like allowing water to retain in those materials or creating cracks in screading on top of them etc. What I noticed is that after the insulating material gets soaked with water during rains, it looses its insulation ability, as the R-value of the insulating material becomes irrelevant and that of water becomes relevant. Water off-course is not a bad conductor and thus the purpose of insulating material dies-- and the insulation system fails.

BENEFITS OF USING RAISED FLOORING FOR INSULATION PURPOSE: Moreover; raised flooring has many other benefits that are not possible with other insulating techniques which are used in the industry today in countries like Pakistan. For example:

• Raised flooring is the best option in old buildings where water lines on the roof does not allow the application of other insulating systems. Almost all multi storied commercial buildings have a complex network of water and air-conditioner pipes over the roof.
• Raised flooring is off-course much cheaper in cost as compared to other options as it does not require any civil works.
• Raised flooring can be a good option for tenants. Usually the landlords refuse to spend on insulation but in this case the tenants can lay the raised flooring themselves to save on Air-conditioning cost and remove at the time they leave premises. The raised flooring can be re-used on new premises or can be sold.
• In case of other options, all water pipes and air-conditioning ducts need to be dismantled and then lay again over the insulation and screading. In Raised flooring, they can be easily concealed under the flooring without any repair work.